Information processing method, information processing system, and program

Abstract

This information processing method is executed by a computer and involves acquiring interface model information indicating an interface model for two or more solid materials (S11), simulating a reaction of the two or more solid materials on the basis of the acquired interface model information (S12), and outputting progress information indicating the degree of progress of the reaction on the basis of reaction information relating to the reaction obtained by simulation (S13 to S15).

Description

Information processing method, information processing system, and program

[0001] The present disclosure relates to a technique for estimating the reaction of two or more solid materials.

[0002] Non-Patent Document 1 discloses a method for determining the reactivity and decomposition products of an interface by performing molecular dynamics (MD) calculations on an interface model between lithium (Li) metal and a solid electrolyte.

[0003] Patent Document 1 discloses a method of performing MD calculations on an interface model of a metal material, performing structural relaxation, and calculating interface energy.

[0004] Japanese Patent Application Laid-Open No. 2022-62524

[0005] Tao Cheng, Boris V. Merinov, Sergey Morozov, and William A. Goddard, III, ACS Energy Lett. 2017, 2, 1454-1459, “Quantum Mechanics Reactive Dynamics Study of Solid Li-Electrode / Li6PS5Cl-Electrolyte Interface”

[0006] The present disclosure provides an information processing method and the like that makes it easy to estimate the degree of progress of a reaction between two or more solid materials.

[0007] An information processing method according to one aspect of the present disclosure is an information processing method executed by a computer, which acquires interface model information indicating an interface model for two or more solid-state materials, performs a simulation of a reaction of the two or more solid-state materials based on the acquired interface model information, and outputs progress information indicating a degree of progress of the reaction based on reaction information regarding the reaction obtained by the simulation. Note that this comprehensive or specific aspect may be realized by an apparatus, a system, an integrated circuit, a computer program, or a computer-readable recording medium, or may be realized by any combination of a method, an apparatus, a system, an integrated circuit, a computer program, and a recording medium. The computer-readable recording medium includes, for example, a non-volatile recording medium such as a CD-ROM (Compact Disc-Read Only Memory).

[0008] According to the present disclosure, it is easy to estimate the degree of progress of a reaction between two or more solid materials.

[0009] FIG. 1 is a block diagram showing an overall configuration including an information processing system according to an embodiment. FIG. 2 is a schematic diagram showing an example of operation by the information processing system according to an embodiment. FIG. 3 is a schematic diagram showing an example of calculation of the degree of progress of a reaction. FIG. 4 is a diagram showing an example of a radial distribution function for lithium metal. FIG. 5 is a diagram showing an example of a radial distribution function for iodine crystals. FIG. 6 is a diagram showing an example of a radial distribution function for lithium iodide crystals. FIG. 7 is a diagram showing an example of calculation of the end time of a reaction using a radial distribution function. FIG. 8 is a diagram showing an example of calculation of the end time of a reaction using a radial distribution function. FIG. 9 is a diagram showing an example of calculation of the end time of a reaction using a radial distribution function. FIG. 10 is a diagram showing an example of calculation of the volume of a reaction product using a coordination number. FIG. 11 is a flowchart showing an example of operation of the information processing system according to an embodiment. FIG. 12 is a flowchart showing an example of operation of calculating the end time of a reaction by the information processing system according to an embodiment. FIG. 13 is a flowchart showing an example of operation of calculating the volume of a reaction product by the information processing system according to an embodiment. FIG. 14 is a diagram showing an example of a first image and a second image displayed on a display unit in the embodiment. FIG. 15 is a diagram showing another example of a second image displayed on the display unit in the embodiment. FIG. 16 is a diagram showing examples of a first image and a third image displayed on the display unit in the embodiment. FIG. 17 is a diagram showing an example of a fourth image displayed on the display unit in the embodiment. FIG. 18 is a diagram showing an example of a fifth image displayed on the display unit in the embodiment. FIG. 19 is a schematic diagram showing an example of calculation of the end time of a reaction using a SOAP descriptor. FIG. 20 is a schematic diagram showing an example of calculation of the end time of a reaction using a SOAP descriptor. FIG. 21 is an explanatory diagram of a reaction occurrence region in an interface model. FIG. 22 is a schematic diagram showing an example of calculation of the volume of a reaction product using a histogram. FIG. 23 is a diagram showing an example of an interface model. FIG. 24 is a diagram showing another example of an interface model. FIG. 25 is a diagram showing yet another example of an interface model.

[0010] (Knowledge that led to the present disclosure) In calculations in recent material development, prediction of reaction rates for reactions between molecules (e.g., gas-phase reactions, etc.) and reactions between molecules and solid surfaces (e.g., catalytic reactions, etc.) can be performed relatively easily and accurately using theories or tools such as transition state theory or the Global Reaction Route Mapping (GRRM) method. On the other hand, no calculation method has been found for the reaction rate of reactions between solid materials (e.g., sintering reactions, etc.).

[0011] For this reason, even if a material with a certain composition is predicted to exhibit good properties, when attempting to mix and react the solid materials contained in that composition to synthesize that material, there is no way to predict how long the reaction should last, or whether synthesizing that material will take so long that it is practically impossible, and the current situation requires a lot of trial and error in experiments.

[0012] Non-Patent Document 1 discloses a method for determining the reactivity and decomposition products of an interface by performing molecular dynamics (MD) calculations on an interface model between lithium (Li) metal and a solid electrolyte. ６ P.S. ５ An interface model was created using Cl, and first-principles MD calculations were performed on the interface model to simulate the chemical reactions that occur at the interface. This interface model is based on the crystalline structure of lithium metal and the solid electrolyte Li ６ P.S. ５ This model is obtained by cutting the Cl crystal structure along a certain crystal orientation plane and gluing the cut surfaces together.

[0013] In Non-Patent Document 1, in order to show that LiCl crystals are generated as a result of the chemical reaction at the interface, the radial distribution function (RDF), which is one of the structural characteristics of the interface model, is compared before and after MD calculation. In the comparison, an RDF peak characteristic of LiCl crystals that was not present before the MD calculation appears after the MD calculation, so the method in Non-Patent Document 1 can show that LiCl crystals are generated by the chemical reaction. However, the method in Non-Patent Document 1 cannot determine the amount of LiCl crystals generated, i.e., the amount of reaction product, and therefore cannot derive the reaction rate.

[0014] Patent Document 1 discloses a method for calculating the interfacial energy by performing MD calculations on an interface model of a metal material, performing structural relaxation, and then calculating the interfacial energy. In the method of Patent Document 1, the MD calculations are used to predict a stable interfacial structure and derive the interfacial energy from the energy difference between the interfacial structure and the structure of the original material, and does not assume that a chemical reaction occurs at the interface. Therefore, the method of Patent Document 1 cannot derive the reaction rate.

[0015] In order to solve the above problems, an information processing method according to a first aspect of the present disclosure is an information processing method executed by a computer, which acquires interface model information indicating an interface model for two or more solid materials, performs a simulation of a reaction of the two or more solid materials based on the acquired interface model information, and outputs progress information indicating the degree of progress of the reaction based on reaction information regarding the reaction obtained by the simulation.

[0016] This has the advantage of making it easier to estimate the degree of reaction progress, rather than simply estimating the reaction products of two or more solid materials. It is possible to grasp the degree of reaction progress without actually synthesizing two or more solid materials. In other words, depending on the degree of reaction progress, users can determine whether or not experimental verification is necessary and set experimental conditions, leading to more efficient material development.

[0017] Also, for example, in the information processing method according to the second aspect of the present disclosure, in the first aspect, the process of outputting the progress information may output the progress information including characteristic information indicating the characteristics of the structure generated by the reaction.

[0018] This has the advantage that it is easy to estimate the characteristics of the structure generated by the reaction of two or more solid materials. Also, by converting the characteristics of the structure into a quantity that indicates the characteristics and outputting it, it has the advantage that it is easy to quantify thresholds such as the time when a chemical reaction starts or ends.

[0019] Furthermore, for example, in the information processing method according to the third aspect of the present disclosure, in the first or second aspect, the two or more solid materials may be a first solid material and a second solid material, and the process of acquiring the interface model information may acquire first structural model information indicating a first structural model for the structure of the first solid material and second structural model information indicating a second structural model for the structure of the second solid material, and generate the interface model by combining the first structural model and the second structural model based on the acquired first structural model information and second structural model information.

[0020] This has the advantage of making it easier to estimate the degree of reaction progress between the first solid material and the second solid material. The degree of reaction progress can be grasped without actually synthesizing the first solid material and the second solid material. In other words, depending on the degree of reaction progress, the user can determine whether or not experimental verification is necessary and set experimental conditions, leading to more efficient material development.

[0021] Also, for example, in the information processing method according to the fourth aspect of the present disclosure, in the first or second aspect, the simulation may be a simulation using a molecular dynamics method, and the reaction information may include first data indicating the interface model corresponding to a start time of the simulation, and second data indicating the interface model corresponding to an end time of the simulation.

[0022] This has the advantage of making it easier to estimate the degree of reaction progress between two or more solid materials. It is possible to grasp the degree of reaction progress without actually synthesizing two or more solid materials. In other words, depending on the degree of reaction progress, users can determine whether or not experimental verification is necessary and set experimental conditions, leading to more efficient material development.

[0023] Furthermore, for example, in the information processing method according to the fifth aspect of the present disclosure, in the fourth aspect, in the process of outputting the progress information, if the interface model indicated by the second data includes a reaction occurrence region in which atoms contained in each of the two or more solid materials are mixed, the progress information including information indicating that the reaction has occurred may be output, and if the interface model indicated by the second data does not include the reaction occurrence region, the progress information including information indicating that the reaction has not occurred may be output.

[0024] This has the advantage of making it easier to estimate whether a reaction between two or more solid materials has occurred. It is possible to grasp the degree of reaction progress without actually synthesizing two or more solid materials. In other words, depending on the degree of reaction progress, users can determine whether or not experimental verification is necessary and set experimental conditions, leading to more efficient material development.

[0025] Also, for example, in the information processing method according to the sixth aspect of the present disclosure, in the fourth or fifth aspect, the process of outputting the progress information may calculate the speed of the reaction based on the difference between the start time and the end time, and output the progress information including the calculated speed of the reaction.

[0026] This has the advantage of making it easier to estimate the reaction rate of two or more solid materials. It is possible to grasp the reaction rate without actually synthesizing two or more solid materials. In other words, depending on the reaction rate, users can determine whether or not experimental verification is necessary and set experimental conditions, leading to more efficient material development.

[0027] Furthermore, for example, in an information processing method according to a seventh aspect of the present disclosure, in any one of the first to sixth aspects, the simulation is a simulation using a molecular dynamics method, and in the process of outputting the progress information, the radial distribution function of one or more atoms included in the interface model during the execution of the simulation may be output as characteristic information indicating the characteristics of the structure generated by the reaction included in the progress information.

[0028] This has the advantage of making it easier to estimate the degree of reaction progress between two or more solid materials. It is possible to grasp the degree of reaction progress without actually synthesizing two or more solid materials. In other words, depending on the degree of reaction progress, users can determine whether or not experimental verification is necessary and set experimental conditions, leading to more efficient material development.

[0029] Furthermore, for example, in the information processing method according to the eighth aspect of the present disclosure, in the seventh aspect, in the process of outputting the progress information, the time at which a predetermined peak included in the radial distribution function disappears at the start time of the simulation may be estimated as the end time of the reaction, and the progress information including the estimated end time of the reaction may be output.

[0030] This has the advantage that it is easy to estimate the completion time of a reaction between two or more solid materials, and further, it has the advantage that it is easy to quantify the reaction rate.

[0031] Furthermore, for example, in the information processing method according to the ninth aspect of the present disclosure, in the seventh or eighth aspect, the process of outputting the progress information may calculate the volume of the reaction product produced by the reaction based on the coordination number of the atoms included in the interface model with respect to a predetermined crystal axis, and output the progress information including the calculated volume of the reaction product.

[0032] This has the advantage that it is easy to estimate the volume of the reaction product produced in the reaction of two or more solid materials, and it also has the advantage that it is easy to quantify the reaction rate.

[0033] Also, for example, in the information processing method according to the tenth aspect of the present disclosure, in the ninth aspect, the process of outputting the progress information may calculate a reaction time indicating the time from when the reaction starts to when it ends based on the difference between the start time and the end time, calculate a rate of the reaction based on the calculated reaction time and the volume of the reaction product, and output the progress information including the calculated rate of the reaction.

[0034] This has the advantage of making it easier to estimate the reaction rate of two or more solid materials. It is possible to grasp the reaction rate without actually synthesizing two or more solid materials. In other words, depending on the reaction rate, users can determine whether or not experimental verification is necessary and set experimental conditions, leading to more efficient material development.

[0035] Also, for example, in an information processing method according to an eleventh aspect of the present disclosure, in any one of the first to tenth aspects, the process of performing the simulation may involve performing a structural relaxation calculation of the interface model based on the acquired interface model information, and performing the simulation on the interface model after the structural relaxation calculation has been performed.

[0036] As a result, even if the gaps between solid materials in an interface model are too large to perform a simulation, the gaps between the solid materials can be reduced to make the simulation easier to perform. Generally, structural relaxation calculations can perform calculations to reduce such gaps faster than molecular dynamics calculations, making it easier to shorten the simulation time. Since the simulation time is shortened, the computer executing the information processing method can save computing resources.

[0037] In addition, an information processing system according to a twelfth aspect of the present disclosure includes a display control unit that, after a first image accepting input of first solid material information indicating a first solid material and second solid material information indicating a second solid material is displayed on a display unit, causes the display unit to display a second image indicating progress information indicating the degree of progress of the reaction between the first solid material and the second solid material, the progress information being generated based on the input first solid material information and second solid material information.

[0038] This allows the user to understand the progress of the reaction between the first solid material and the second solid material by looking at the second image. The progress of the reaction can be understood without actually synthesizing the first solid material and the second solid material. In other words, depending on the progress of the reaction, the user can determine whether or not experimental verification is necessary and can formulate experimental conditions, which leads to more efficient material development.

[0039] Furthermore, for example, in the information processing system according to the thirteenth aspect of the present disclosure, in the twelfth aspect, the display control unit may further display on the display unit a third image showing first interface model information generated based on the input first solid material information and the second solid material information, and the first interface model information may show a first interface model including a boundary region between the first structure and the second structure, which is generated by contact between the first solid material having a first structure including a plurality of first atoms and the second solid material having a second structure including a plurality of second atoms.

[0040] This allows the user to understand what kind of interface model is used to simulate the reaction by looking at the third image, which allows the user to visually confirm not only the composition information of the material but also its structure information, making it easier to confirm whether the expected reaction can be simulated.

[0041] Also, for example, in an information processing system relating to a fourteenth aspect of the present disclosure, in the thirteenth aspect, the display control unit may further display on the display unit a fourth image that accepts input of calculation method information indicating a calculation method that can be executed on the first interface model, and may further display on the display unit a fifth image that indicates second interface model information generated based on the input calculation method information.

[0042] The display control unit further displays a fourth image on the display unit, which accepts input of calculation method information indicating calculation methods that can be executed on the first interface model. This allows a user to select a calculation method that they want to execute on the interface model by looking at the fourth image. By presenting options in advance, even a user who is not familiar with calculation methods can select a calculation method that is appropriate to a certain extent, making it easier to perform chemical reaction simulations.

[0043] The display control unit further causes the display unit to display a fifth image indicating second interface model information generated based on the input calculation method information.

[0044] This allows the user to understand the interface model after the simulation is performed by looking at the fifth image. By visualizing the interface model after the simulation is performed, it becomes easier to confirm whether a chemical reaction is occurring, and the user can determine whether or not experimental verification is necessary and determine the experimental conditions, leading to more efficient material development.

[0045] In addition, a program according to a fifteenth aspect of the present disclosure causes a computer to execute the steps of acquiring interface model information indicating an interface model for two or more solid materials, performing a simulation of a reaction of the two or more solid materials based on the acquired interface model information, and outputting progress information indicating a degree of progress of the reaction based on reaction information regarding the reaction obtained by the simulation, wherein each of the two or more solid materials includes a plurality of atoms.

[0046] This has the advantage of making it easier to estimate the degree of reaction progress, rather than simply estimating the reaction products of two or more solid materials. It is possible to grasp the degree of reaction progress without actually synthesizing two or more solid materials. In other words, depending on the degree of reaction progress, users can determine whether or not experimental verification is necessary and set experimental conditions, leading to more efficient material development.

[0047] Furthermore, the information processing method of the present disclosure can be realized as a computer program that causes a computer to execute the characteristic processes included in the information processing method of the present disclosure. Needless to say, such a computer program can be distributed on a computer-readable non-transitory recording medium such as a CD-ROM or via a communication network such as the Internet.

[0048] Hereinafter, the embodiments will be specifically described with reference to the drawings.

[0049] The embodiments described below are comprehensive or specific examples of the present disclosure. The numerical values, shapes, materials, components, component placement and connection configurations, steps, and step order shown in the following embodiments are merely examples and are not intended to limit the present disclosure. Furthermore, among the components in the following embodiments, components that are not described in the independent claims that represent the highest concepts are described as optional components. Furthermore, each figure is a schematic diagram and is not necessarily an exact illustration. Furthermore, the same components are designated by the same reference numerals in each figure.

[0050] Furthermore, the information processing system according to the embodiment of the present disclosure may be configured so that all components are included in one computer, or may be configured as a system in which multiple components are distributed across multiple computers.

[0051] (Embodiment) Hereinafter, an information processing system (information processing method or program) according to an embodiment of the present disclosure will be described with reference to the drawings.

[0052] [Information Processing System] First, the configuration of an information processing system used in the embodiment will be described.

[0053] 1 is a block diagram showing an overall configuration including an information processing system 100 according to an embodiment. The information processing system 100 is configured as a computer such as a personal computer or a server. That is, the information processing system 100 may be realized by cloud computing, for example. In the embodiment, the information processing system 100 will be described as being a stationary computer.

[0054] The information processing system 100 includes an acquisition unit 11, a processing unit 12, an output unit 13, and a storage unit 14. The information processing system 100 is also connected to an input unit 2, a display control unit 30, and a display unit 3. The input unit 2, the display control unit 30, and the display unit 3 are configured by an information terminal used by a user, such as a smartphone, a tablet terminal, or a personal computer.

[0055] The input unit 2 and the display control unit 30 may both be connected to the information processing system 100 via a LAN (Local Area Network) or the like, or may be connected to the information processing system 100 via a network such as the Internet.

[0056] The input unit 2 is an input interface that accepts user input and is configured, for example, with a keyboard, a touch sensor, a touchpad, or a mouse. The input unit 2 accepts input operations by the user and outputs a signal corresponding to the input operation to the information processing system 100. In the present disclosure, the display unit 3 and the input unit 2 are configured independently of each other, but they may be configured integrally like a touch panel. In the present disclosure, the information processing system 100 does not include the display unit 3 or the input unit 2, but may include these.

[0057] The input unit 2 accepts input of solid material information indicating each of two or more solid materials desired by the user. In the embodiment, the input unit 2 accepts input of first solid material information indicating a first solid material and second solid material information indicating a second solid material. Of course, the input unit 2 may accept input of solid material information for each of three or more solid materials. The information accepted by the input unit 2 is, for example, the material name (including the compound name) of the solid material, a composition formula indicating the composition of the solid material, or a crystal structure of the solid material.

[0058] The display control unit 30 causes the display unit 3 to display images and the like based on information output from the output unit 13 of the information processing system 100 .

[0059] The display unit 3 displays images and the like under the control of the display control unit 30. The display unit 3 is, for example, a liquid crystal display, a plasma display, an organic EL (Electro-Luminescence) display, or the like, but is not limited to these.

[0060] The acquisition unit 11 acquires interface model information indicating interface models for two or more solid-state materials. The acquisition unit 11 is an entity that executes the step of acquiring interface model information in the information processing method of the present disclosure. In the embodiment, the acquisition unit 11 acquires first structural model information indicating a first structural model for the structure of the first solid-state material based on first solid-state material information received by the input unit 2. Furthermore, the acquisition unit 11 acquires second structural model information indicating a second structural model for the structure of the second solid-state material based on second solid-state material information received by the input unit 2.

[0061] Here, when the crystal structures of the first solid material and the second solid material are input to the input unit 2, the acquisition unit 11 acquires first structural model information in which the crystal structure of the input first solid material is used as the first structural model, and second structural model information in which the crystal structure of the input second solid material is used as the second structural model. On the other hand, when the crystal structures of the first solid material and the second solid material are not input to the input unit 2, the acquisition unit 11 may acquire the first structural model information and the second structural model information by, for example, acquiring the first structural model and the second structural model corresponding to the material names (or composition formulas) of the first solid material and the second solid material, respectively, from an external database. Furthermore, the acquisition unit 11 may acquire the first structural model information and the second structural model information by, for example, inputting the material names (or composition formulas) of the first solid material and the second solid material to a prediction system capable of predicting structural models and acquiring the first structural model and the second structural model predicted by the prediction system.

[0062] The acquisition unit 11 then acquires the interface model by generating an interface model that combines the first structural model and the second structural model based on the acquired first structural model information and second structural model information. Specifically, the acquisition unit 11 uses appropriate material analysis software to generate the interface model by superimposing any crystal plane of the first structural model on any crystal plane of the second structural model. In the process of generating the interface model, the crystal plane to be used may be determined by, for example, specifying Miller indices, or a default crystal plane may be used. Furthermore, in the process of generating the interface model, a certain degree of distortion may be allowed, and the degree of distortion to be allowed may be set appropriately by the user.

[0063] The processing unit 12 executes a simulation of a reaction of two or more solid materials based on the interface model information acquired by the acquisition unit 11. The processing unit 12 is an entity that executes the step of executing a simulation in the information processing method of the present disclosure. In the embodiment, the processing unit 12 executes a structural relaxation calculation of the interface model based on the interface model information acquired by the acquisition unit 11, and executes a simulation on the interface model after the structural relaxation calculation has been executed.

[0064] Here, the structural relaxation calculation is a calculation that optimizes the lattice constant of the interface model and the coordinates (positions) of each atom in the interface model. Specifically, the structural relaxation calculation calculates the force acting on each atom in the interface model using first-principles calculations and optimizes the coordinates of each atom so that the force acting on each atom is zero or below a threshold. When the structural relaxation calculation of the interface model is performed, for example, even if the gaps between solid materials in the interface model are too large to perform a simulation, the gaps between the solid materials can be reduced to make the simulation easier to perform. Note that the user can appropriately set whether or not to perform the structural relaxation calculation. If the structural relaxation calculation is not performed, the processing unit 12 performs a simulation on the interface model acquired by the acquisition unit 11.

[0065] In the embodiment, the processing unit 12 executes a simulation by performing a molecular dynamics calculation (MD calculation) on the interface model after the structural relaxation calculation. That is, the simulation executed by the processing unit 12 is a simulation using the molecular dynamics method. Details of the processing executed by the processing unit 12 will be described later.

[0066] The output unit 13 outputs images, etc. to the display control unit 30, thereby displaying the images, etc. on the display unit 3. The output unit 13 also outputs progress information indicating the degree of progress of a reaction, based on reaction information regarding the reaction obtained by the simulation in the processing unit 12. The output unit 13 is the entity that executes the step of outputting the progress information in the information processing method of the present disclosure. Specifically, the output unit 13 outputs the progress information by displaying an image representing the progress information generated by the processing unit 12 on the display unit 3. Details of the processing executed by the output unit 13 will be described later.

[0067] Here, the progress information may include, for example, information indicating whether a reaction of two or more solid materials has occurred. Furthermore, if a reaction of two or more solid materials has occurred, the progress information may include information indicating the time required for the reaction (i.e., reaction time) or the reaction rate. Furthermore, if a reaction of two or more solid materials has occurred, the progress information may include, for example, characteristic information indicating the characteristics of the structure produced by the reaction.

[0068] The characteristic information may include, for example, a radial distribution function (RDF), a bond order parameter, or a coordination environment such as a coordination number. Furthermore, the characteristic information may include, for example, a SOAP (Smooth Overlap of Atomic Positions) descriptor. In the embodiment, an example in which the radial distribution function and the coordination number are used as the characteristic information will be described. An example in which the SOAP descriptor is used as the characteristic information will be described in a modified example.

[0069] The storage unit 14 is a recording medium for storing data (including programs) used in various processes that can be executed by the information processing system 100. The recording medium is, for example, a hard disk drive, a RAM (Random Access Memory), a ROM (Read Only Memory), or a semiconductor memory. Note that such a recording medium may be volatile or non-volatile.

[0070] [Processing] Next, an example of processing executed by the information processing system 100 according to the embodiment will be described with reference to the drawings. Fig. 2 is a schematic diagram showing an example of operation of the information processing system 100 according to the embodiment. As shown in Fig. 2(a), first, the input unit 2 receives input of solid material information indicating each of two or more solid materials. In the example shown in Fig. 2(a), the input unit 2 receives information indicating the structure of lithium metal as first solid material information (e.g., a CIF (Caltech Intermediate Form) file) and information indicating the structure of iodine crystal as second solid material information (e.g., a CIF file).

[0071] Next, as shown in (b) of FIG. 2, the acquisition unit 11 of the information processing system 100 acquires an interface model by generating it based on the solid material information received by the input unit 2. In the example shown in (b) of FIG. 2, the acquisition unit 11 generates an interface model consisting of 120 lithium atoms and 72 iodine atoms. Next, as shown in (c) of FIG. 2, the processing unit 12 of the information processing system 100 acquires an interface model after the structural relaxation calculation by performing a structural relaxation calculation based on the interface model information acquired by the acquisition unit 11. In the structural relaxation calculation, the lattice constant may be variable.

[0072] Next, as shown in FIG. 2(d), the processing unit 12 of the information processing system 100 generates time-series data of the interface model by performing MD calculations (i.e., simulations using the molecular dynamics method) using the interface model after the structural relaxation calculation as the initial structure. FIG. 2(d) shows the interface model corresponding to the last data among the time-series data of the interface model. In the MD calculations, the lattice constant is fixed. Here, the MD calculations were performed for a total of 5,000 steps, with each step being 2 fs (femtoseconds). In other words, the MD calculations were performed for 10 ps (picoseconds). The MD calculations were performed while the set temperature of the interface model was increased at a constant rate from 0 K to 300 K. In the MD calculations, the set temperature of the interface model may be maintained at a constant temperature, or may be further increased to simulate a sintering reaction, for example.

[0073] Next, the output unit 13 of the information processing system 100 outputs progress information based on reaction information related to the reaction obtained by the simulation in the processing unit 12. Here, the output unit 13 outputs the progress information using, as reaction information, an interface model corresponding to the first data and an interface model corresponding to the last data among the time-series data of the interface model obtained by the MD calculation. In other words, the reaction information includes first data indicating the interface model corresponding to the start time of the simulation and second data indicating the interface model corresponding to the end time of the simulation.

[0074] FIG. 3 is a schematic diagram showing an example of calculation of the reaction progress. As shown in FIG. 3(a), the interface model has a region where lithium atoms and iodine atoms are mixed, unlike the initial structure before MD calculation. FIG. 3(b) is an enlarged view of the region surrounded by the dashed line in FIG. 3(a). FIG. 3(c) shows the known crystal structure of lithium iodide. As shown in FIG. 3(b), the region where lithium atoms and iodine atoms are mixed contains many tetrahedral structures of iodine atoms centered on lithium atoms. All of these tetrahedral structures are very similar to the crystal structure of lithium iodide shown in FIG. 3(c).

[0075] In other words, when the interface model shown in Figure 3 is displayed on the display unit 3, the user can visually check the interface model and determine that all of the iodine atoms present in the initial structure have reacted with lithium atoms, resulting in lithium iodide as the reaction product.

[0076] In the interface model shown in FIG. 3, the volume of the region where lithium iodide is generated, that is, the volume V of the reaction product, is V = 4293 [Å ３ ] can be visually calculated by the user. In addition, the number of crystalline structures of the generated lithium iodide is 72, which corresponds to the number of iodine atoms, since all iodine atoms have reacted. Therefore, the output unit 13 can calculate the reaction rate by receiving the input of the volume of the reaction product and the number of reaction products from the input unit 2. Here, the reaction rate v is expressed as v = 72 / V / N Ａ / 10 ps ≒ 2.79 x 10 １５ [mol / m ３ / s]. Ａ " is Avogadro's number. Therefore, the output unit 13 can output progress information including the reaction speed v. In this way, in the process of outputting progress information, the reaction speed v is calculated based on the difference between the start time and the end time of the simulation, and progress information including the calculated reaction speed v can be output.

[0077] 3, the output unit 13 calculates the reaction rate using information obtained by the user's visual inspection (the number of reaction products and the volume of the reaction products). However, if more complex reaction products are produced or if unknown reaction products are produced, it may be difficult to accurately calculate the reaction rate using the above method. Furthermore, in the example shown in FIG. 3, the execution time of the MD calculation is taken as the reaction time, so the estimated reaction time may be longer than the actual reaction time.

[0078] Therefore, in the following, we will explain a process that can solve the above problems: a process for calculating the reaction time using a radial distribution function, which is a type of characteristic information that indicates the characteristics of an interface model; and a process for calculating the volume of a reaction product using a coordination number, which is also a type of characteristic information.

[0079] First, the process of calculating the reaction time using the radial distribution function will be described. The radial distribution function for a certain atom represents the correlation between the distance from that atom to other atoms and the probability that other atoms exist at that distance. The radial distribution function of the interface model is expressed by calculating the average of the radial distribution functions for atoms in the interface model, and is a feature of the interface model that makes it easy to understand the distribution of distances between atoms in the interface model.

[0080] FIG. 4 is a diagram showing an example of a radial distribution function for lithium metal. In the graph shown in FIG. 4, the vertical axis represents the radial distribution function "g(r)" and the horizontal axis represents the interatomic distance "r". This is also true for the graphs shown in FIGS. 5 to 9 described below. As shown in FIG. 4, a peak of the radial distribution function occurs for each distance between lithium atoms. The radial distribution function may be defined by focusing on a certain atom and expressing the number of atoms located around it as a function of the distance r. In FIG. 4, l(Li0-Li0) may be the interatomic distance between lithium atoms in the crystal structure of lithium.

[0081] 5 is a diagram showing an example of the radial distribution function for iodine crystals, in which peaks appear at each distance between iodine atoms.

[0082] 6 is a diagram showing an example of the radial distribution function for lithium iodide crystal. As shown in FIG. 6, a peak of the radial distribution function occurs for each distance between lithium atoms. In addition, a peak of the radial distribution function occurs for each distance between iodine atoms. In addition, a peak of the radial distribution function occurs for each distance between lithium atoms and iodine atoms. In this way, when a crystal structure contains multiple types of atoms, the radial distribution function is defined for each combination of two atoms.

[0083] 7 is a schematic diagram showing an example of calculating the end time of a reaction using a radial distribution function. The top three graphs in FIG. 7 represent, from left to right, the radial distribution function for lithium atom-lithium atom, the radial distribution function for lithium atom-iodine atom, and the radial distribution function for iodine atom-iodine atom in the interface model before MD calculation. The bottom three graphs in FIG. 7 represent, from left to right, the radial distribution function for lithium atom-lithium atom, the radial distribution function for lithium atom-iodine atom, and the radial distribution function for iodine atom-iodine atom in the interface model after MD calculation.

[0084] 7, the radial distribution function for iodine atoms is shown to have a peak at an interatomic distance of approximately 3 Å, which existed before the MD calculation, but disappeared after the MD calculation (see the area surrounded by the dashed line). This means that the iodine crystals in the solid materials (lithium metal and iodine crystals) were consumed and the reaction was completed.

[0085] That is, the output unit 13 (in the process of outputting the progress information) can estimate the time at which a predetermined peak included in the radial distribution function disappears at the start time of the simulation as the end time of the reaction, and output the progress information including the estimated end time of the reaction. Note that the output unit 13 (in the process of outputting the progress information) may also estimate the time at which a new peak appears in the radial distribution function during the execution of the simulation and the peak stops fluctuating with the passage of time as the end time of the reaction, for example.

[0086] 8 and 9 are schematic diagrams showing examples of calculations of the end time of a reaction using a radial distribution function. Both FIGS. 8 and 9 show time-series data of the characteristics of the interface model (here, radial distribution function) obtained by MD calculation. In each of FIGS. 8 and 9, the solid line represents the radial distribution function for lithium atom-lithium atom, the dotted line represents the radial distribution function for iodine atom-iodine atom, and the thick solid line represents the radial distribution function for lithium atom-iodine atom. Also, (a) of FIG. 8 shows data at the start of the MD calculation, and (b) of FIG. 8 shows data 1 ps after the start of the MD calculation. Also, (a) of FIG. 9 shows data 2 ps after the start of the MD calculation, (b) of FIG. 9 shows data 3 ps after the start of the MD calculation, and (c) of FIG. 9 shows data 4 ps after the start of the MD calculation. The vertical axis of the graphs shown in FIGS. 8 and 9 represents the radial distribution function "g(r)" and the horizontal axis represents the pair separation distance "r".

[0087] As shown in Figures 8 and 9, when focusing on the radial distribution function for iodine atoms, the peak that occurred near an interatomic distance of 3 Å gradually decreases over time. This indicates that the iodine crystals are being consumed, that is, the reaction is progressing. Then, as shown in Figure 9(c), the peak disappears 4 ps after the start of the MD calculation. Therefore, the output unit 13 (in the process of outputting progress information) estimates the time 4 ps after the start of the MD calculation as the end time.

[0088] Next, a process for calculating the volume of the reaction product using the coordination number will be described. First, the output unit 13 calculates the coordination number of each atom (here, lithium atom and iodine atom) included in the interface model using the interface model at the end time of the above-mentioned reaction. The coordination number can be calculated using an appropriate algorithm such as crystalNN implemented in pymatgen. For details of this algorithm, please refer to the literature (Hillary Pan, Alex M. Ganose, Matthew Horton, Muratahan Aykol, Kristin A. Persson, Nils ER Zimmermann, and Anubhav Jain, Inorg. Chem. 2021, 60, 3, 1590-1603, "Benchmarking Coordination Number Prediction Algorithms on Inorganic Crystal Structures").

[0089] Figure 10 is a schematic diagram showing an example of calculating the volume of a reaction product using coordination number. Figure 10 shows a graph in which the calculated coordination number is plotted against the c-axis coordinate. In Figure 10, the vertical axis represents the coordination number, and the horizontal axis represents the fractional coordinate in the c-axis direction. Also, in Figure 10, circles represent the number of iodine atoms coordinated to a lithium atom, and crosses represent the number of lithium atoms coordinated to an iodine atom.

[0090] As already explained, all iodine atoms present in the solid material are present in the reaction product after the reaction is completed. This corresponds to the fact that the number of lithium atoms coordinated to each iodine atom is not zero in FIG. 10 . Note that the coordination number is, by definition, expressed as a non-negative integer. Therefore, in other words, the fact that all iodine atoms present in the solid material are present in the reaction product corresponds to the fact that the number of lithium atoms coordinated to each iodine atom is 1 or more in FIG. 10 . The proportion of the region of the fractional coordinate in the c-axis direction where the number of lithium atoms coordinated to each iodine atom is 1 or more in the entire region (hereinafter referred to as the "specific region") can be considered to be the proportion of the reaction product in the entire interface model.

[0091] Therefore, it is possible to calculate the volume of the reaction product based on the ratio of the specific region to the entire region. In other words, the output unit 13 (in the process of outputting the progress information) can calculate the volume of the reaction product generated by the reaction based on the coordination number of the atoms included in the interface model with respect to a predetermined crystal axis (here, the c-axis), and output the progress information including the calculated volume of the reaction product.

[0092] In the example shown in FIG. 10, the specific region is in the range of c = [0.0, 0.1] and the range of c = [0.35, 1.0]. Therefore, the output unit 13 can calculate the ratio of the specific region to the entire region as 0.75. Then, the output unit 13 can calculate the volume of the reaction product by multiplying the volume of the interface model by this ratio. In this example, the volume V of the reaction product is V = 5448 × 0.75 = 4086 [Å]. Then, the output unit 13 calculates the reaction rate v as v = 72 / V / N Ａ / 4 ps ≒ 7.32 x 10 １５ [mol / m ３ / s] can be calculated.

[0093] In this way, by using feature information indicating the features of the interface model, the information processing system 100 can calculate the reaction time and reaction rate with higher accuracy than when using information obtained by visual inspection by a user. Furthermore, by using the feature information, the information processing system 100 can calculate the reaction time and reaction rate even when, for example, more complex reaction products are produced or unknown reaction products are produced.

[0094] [Operation] The following describes the operation (i.e., information processing method) of the information processing system 100 according to the embodiment. Fig. 11 is a flowchart showing an example of the operation of the information processing system 100 according to the embodiment.

[0095] (Step S10) The acquisition unit 11 acquires solid material information. In this embodiment, the solid material information includes first solid material information and second solid material information. The solid material information is input by the user using the input unit 2, and is acquired by the acquisition unit 11.

[0096] (Step S11) The acquisition unit 11 acquires interface model information. In the embodiment, the acquisition unit 11 acquires first structural model information and second structural model information based on the first solid-state material information and second solid-state material information, respectively, received by the input unit 2. Then, the acquisition unit 11 acquires the interface model by generating an interface model based on the acquired first structural model information and second structural model information.

[0097] (Step S12) The processing unit 12 executes a simulation based on the interface model information acquired by the acquisition unit 11. In the embodiment, the processing unit 12 executes a structural relaxation calculation of the interface model based on the interface model information acquired by the acquisition unit 11, and executes a simulation on the interface model after the structural relaxation calculation has been executed. The processing unit 12 also executes an MD calculation as the simulation.

[0098] (Step S13) The output unit 13 acquires a reaction time based on reaction information related to the reaction obtained by the simulation in the processing unit 12. Here, for example, when the user visually checks the interface model displayed on the display unit 3 and determines that a reaction product is being produced, the output unit 13 acquires the execution time of the simulation as the reaction time. The output unit 13 also acquires the reaction time by calculating the end time of the reaction using, for example, a feature of the interface model (here, a radial distribution function). An example of the operation of calculating the end time of the reaction will be described below with reference to FIG. 12. FIG. 12 is a flowchart showing an example of the operation of calculating the end time of the reaction by the information processing system 100 according to the embodiment.

[0099] (Step S131) ​​First, the output unit 13 calculates time-series data of features from the time-series data of the interface model obtained by simulation. Here, the output unit 13 calculates time-series data of the radial distribution function for each atom included in the interface model from the time-series data of the interface model.

[0100] (Step S132) Next, the output unit 13 detects the time when the feature pattern changes and acquires the detected time as the end time. Here, the output unit 13 detects the time when a predetermined peak included in the radial distribution function disappears at the start time of the simulation and acquires the detected time as the end time of the reaction.

[0101] (Step S14) Returning to FIG. 11 , the output unit 13 acquires the volume of the reaction product based on the reaction information related to the reaction obtained by the simulation in the processing unit 12. Here, when the output unit 13 determines that a reaction product has been generated by, for example, visually inspecting the interface model displayed on the display unit 3, the output unit 13 acquires the volume of the reaction product input by the user using the input unit 2. Furthermore, the output unit 13 acquires the volume of the reaction product by calculating the volume of the reaction product using, for example, the characteristics of the interface model (here, the coordination number). An example of the operation of calculating the volume of the reaction product will be described below with reference to FIG. 13 . FIG. 13 is a flowchart showing an example of the operation of calculating the volume of the reaction product by the information processing system 100 according to the embodiment.

[0102] (Step S141) First, the output unit 13 acquires an interface model at the end time of the reaction.

[0103] (Step S142) Next, the output unit 13 calculates and acquires the coordination number of each atom included in the interface model with respect to a predetermined crystal axis (here, the c-axis).

[0104] (Step S143) Then, the output unit 13 calculates the volume of the reaction product based on the calculated coordination number. Here, the output unit 13 calculates the ratio of the reaction product to the entire interface model based on the coordination number, and calculates the volume of the reaction product by multiplying the ratio by the volume of the interface model.

[0105] 11 , the output unit 13 outputs progress information. Here, the output unit 13 calculates the reaction rate based on the reaction time acquired in step S13 and the volume of the reaction product acquired in step S14, and outputs progress information including the calculated reaction rate.

[0106] If the interface model corresponding to the end time of the simulation does not contain any reaction products, the output unit 13 outputs progress information including information indicating that no reaction has occurred without executing steps S13 and S14. That is, if the interface model indicated by the second data (the interface model corresponding to the end time of the simulation) contains a reaction occurrence region in which atoms contained in each of two or more solid materials are mixed, the output unit 13 outputs progress information including information indicating that a reaction has occurred. On the other hand, if the interface model indicated by the second data does not contain a reaction occurrence region, the output unit 13 outputs progress information including information indicating that no reaction has occurred.

[0107] [Example of Use] An example of use of the information processing system 100 according to the embodiment will be described below. Fig. 14 is a diagram showing an example of a first image and a second image displayed on the display unit 3 in the embodiment. (a) of Fig. 14 shows an example of a first image displayed on the display unit 3 by the display control unit 30. The first image is an image that accepts input of first solid material information indicating a first solid material and second solid material information indicating a second solid material. In the embodiment, the first image includes a first input area for inputting the first solid material information, a second input area for inputting the second solid material information, an execution icon called "Execute Reaction Sim," and an execution icon called "Modify."

[0108] The first input area displays a text box for inputting the material name (or composition formula) of the first solid material and a first structural model corresponding to the input first solid material. The second input area displays a text box for inputting the material name (or composition formula) of the second solid material and a second structural model corresponding to the input second solid material. As already described, if the user inputs the crystal structures of the first and second fixed materials into the input unit 2, the crystal structure of the input first fixed material is displayed as the first structural model, and the crystal structure of the input second fixed material is displayed as the second structural model on the display unit 3. On the other hand, if the crystal structures of the first and second solid materials are not input into the input unit 2, the first structural model and the second structural model corresponding to the first and second solid materials, respectively, obtained from, for example, an external database, are displayed on the display unit 3.

[0109] The user inputs the material names (or composition formulas) of the first and second solid materials into the first and second input areas, respectively, and selects the execution icon "Run Reaction Sim." This causes the processing unit 12 to execute the simulation, and then the output unit 13 outputs progress information. If the user wishes to modify the information they have entered, they can select the execution icon "Modify" to modify the input content as appropriate.

[0110] 14(b) shows an example of a second image that the display control unit 30 causes the display unit 3 to display. The second image is an image showing progress information indicating the progress of the reaction between the first solid material and the second solid material, generated based on the input first solid material information and second solid material information. The second image is displayed on the display unit 3 after the user selects an execution icon called "Run Reaction Sim" in the first image. The second image includes the name (or composition formula) of the reaction product generated by the reaction between the first solid material and the second solid material, the reaction rate, and an execution icon called "Display Structure." When the user selects the execution icon called "Display Structure," the display unit 3 displays an interface model after the simulation has been executed.

[0111] Here, if the result of the simulation by the processing unit 12 is that no reaction products are generated, the second image shown in FIG. 15 is displayed on the display unit 3. FIG. 15 is a diagram showing another example of the second image displayed on the display unit 3 in the embodiment. In the example shown in FIG. 15, the second image includes the character string "error" indicating that no reaction products are generated, an execution icon "Return to setting screen," and an execution icon "Exit." If the user selects the execution icon "Return to setting screen," the first image is displayed again on the display unit 3. Furthermore, if the user selects the execution icon "Exit," the operation of the information processing system 100 is terminated.

[0112] As shown in Figure 14(b) and Figure 15, the user can understand the progress of the reaction between the first solid material and the second solid material by looking at the second image. Here, the user can understand whether a reaction has occurred by looking at the second image. Furthermore, the user can understand the speed of the reaction if a reaction has occurred by looking at the second image.

[0113] FIG. 16 shows examples of a first image and a third image displayed on the display unit 3 in the embodiment. (a) of FIG. 16 shows an example of a first image displayed on the display unit 3 by the display control unit 30. The first image shown in (a) of FIG. 16 differs from the first image shown in (a) of FIG. 14 in that it includes an execution icon called "Interface Model Generation" instead of the execution icons called "Reaction Sim Execution" and "Modification." The user inputs the material names (or composition formulas) of the first and second solid materials in the first and second input fields, respectively, and selects the execution icon called "Interface Model Generation." The acquisition unit 11 then generates an interface model based on the input first solid material information and second solid material information. This interface model is referred to as the "first interface model."

[0114] The first interface model is a model including a boundary region between a first structure and a second structure, which is generated by contact between a first solid material having a first structure including a plurality of first atoms and a second solid material having a second structure including a plurality of second atoms, where the first atoms are lithium atoms, the first structure is a crystalline structure of lithium metal, the second atoms are iodine atoms, and the second structure is a crystalline structure of iodine crystals.

[0115] (b) of Fig. 16 shows an example of a third image that the display control unit 30 causes to be displayed on the display unit 3. The third image is an image showing the first interface model information. As shown in (b) of Fig. 16, the third image includes an image showing the interface model (first interface model) generated by the acquisition unit 11. By looking at the third image, the user can understand what kind of interface model is to be used to simulate the reaction.

[0116] 17 is a diagram showing an example of a fourth image displayed on the display unit 3 in the embodiment. The display control unit 30 may display the fourth image on the display unit 3 after displaying the third image on the display unit 3, or may display the fourth image on the display unit 3 alongside the third image. The fourth image is an image that accepts input of calculation method information indicating a calculation method that can be executed on the interface model (first interface model) generated by the acquisition unit 11. In the embodiment, the fourth image includes a first setting area for inputting settings for the structural relaxation calculation, a second setting area for inputting settings for the MD calculation, and an execution icon labeled "Execute calculation."

[0117] The first setting area displays a check box for selecting whether or not to perform a structural relaxation calculation, and a character string representing the convergence condition of the structural relaxation calculation. The convergence condition of the structural relaxation calculation may be changeable as appropriate by user input. The second setting area displays a check box for selecting whether or not to perform an MD calculation, and a character string representing the calculation time and temperature conditions of the MD calculation. The temperature condition of the MD calculation may be changeable as appropriate by user input.

[0118] The user selects the calculation method they want to execute in the first setting area and the second setting area, and then selects the execution icon "Execute calculation." This causes the processing unit 12 to execute at least one of a structural relaxation calculation and an MD calculation. When the processing unit 12 executes an MD calculation, the output unit 13 outputs progress information. By viewing the fourth image, the user can select the calculation method they want to execute on the interface model.

[0119] FIG. 18 is a diagram showing an example of a fifth image displayed on the display unit 3 in the embodiment. The display control unit 30 causes the display unit 3 to display the fifth image after the simulation in the processing unit 12 is completed. The fifth image is an image showing second interface model information generated based on the input calculation method information. As shown in FIG. 18, the fifth image includes an image showing the interface model (second interface model) after the simulation (here, MD calculation) in the processing unit 12 is performed, the name (or composition formula) of the reaction product, the reaction rate, and an execution icon called "feature extraction." Note that if no reaction product is generated as a result of the simulation by the processing unit 12, the name of the reaction product and the reaction rate are not included in the fifth image.

[0120] When the user selects the execution icon "Feature Extraction," time-series data of the interface model features (e.g., radial distribution function) are displayed on the display unit 3. By looking at the fifth image, the user can understand the interface model after the simulation is executed.

[0121] [Advantages] As described above, the information processing system 100 (information processing method) according to the embodiment can output progress information indicating the degree of progress of the reaction by executing a simulation of the reaction of two or more solid materials. Therefore, the information processing system 100 according to the embodiment has the advantage of easily estimating the degree of progress of the reaction rather than simply estimating the reaction product of two or more solid materials. Therefore, the information processing system 100 according to the embodiment has the advantage of easily allowing a user to grasp, for example, the rate of the reaction of two or more solid materials, how the reaction of two or more solid materials will proceed, or whether a reaction will not occur at all.

[0122] (Modifications) Hereinafter, an information processing system (information processing method) according to one or more aspects of the present disclosure has been described based on embodiments, but the present disclosure is not limited to the above-described embodiments. As long as it does not deviate from the spirit of the present disclosure, various modifications that a person skilled in the art can conceive of to the above-described embodiments may also be included in the present disclosure.

[0123] For example, the output unit 13 (in the process of outputting progress information) may calculate the reaction completion time using a SOAP descriptor as feature information indicating the features of the interface model. Here, the SOAP descriptor is a descriptor used to express the local atomic environment. The SOAP descriptor captures the local chemical environment around the atom, is coded as a mathematical expression, and is used for comparing different atomic configurations.

[0124] The output unit 13 calculates time-series data for a large number (e.g., several hundred) of SOAP descriptors for the interface model, and extracts time-series data in which the value of the SOAP descriptor changes relatively significantly over time from the calculated time-series data for the large number of SOAP descriptors. FIG. 19 is a schematic diagram showing an example of calculating the end time of a reaction using SOAP descriptors. FIG. 20 is a schematic diagram showing an example of calculating the end time of a reaction using SOAP descriptors. FIG. 19 shows nine time-series data in which the value of the SOAP descriptor changes relatively significantly over time. FIG. 20 shows an example of time-series data for the SOAP descriptors. In each graph shown in FIGS. 19 and 20, the vertical axis represents the value of the SOAP descriptor, and the horizontal axis represents the number of steps in the MD calculation, in other words, the calculation time. As shown in FIGS. 19 and 20, in many of the time-series data for the SOAP descriptors, the value of the SOAP descriptor is saturated at approximately the 2000th step. Therefore, the output unit 13 can estimate that the reaction has finished at the 2000th step of the MD calculation, in other words, 4 ps after the start of the simulation. Note that the output unit 13 may, for example, calculate the number of steps at which the value of the SOAP descriptor saturates for each of the time-series data of a large number of SOAP descriptors, and estimate a representative value of these numbers of steps (for example, the average, mode, or median) as the end time of the reaction.

[0125] Furthermore, for example, the output unit 13 (in the process of outputting progress information) may calculate the volume of the reaction product using a histogram as feature information indicating the features of the interface model. FIG. 21 is an explanatory diagram of a reaction occurrence region in an interface model. FIG. 21 shows an interface model after a reaction in which lithium metal is the first solid material and iodine crystals are the second solid material. In FIG. 21 , a large amount of lithium iodide, the reaction product, is present in the region surrounded by a solid line, and this region corresponds to the reaction occurrence region. Here, if it is possible to quantitatively distinguish between the reaction occurrence region (i.e., the region where lithium atoms and iodine atoms are mixed) and other regions (i.e., the region where only lithium atoms are present), it is possible to calculate the proportion of the reaction occurrence region to the entire interface model, thereby enabling the volume of the reaction product to be calculated.

[0126] FIG. 22 is a schematic diagram showing an example of calculating the volume of a reaction product using a histogram. (a) of FIG. 22 is a histogram generated by the output unit 13 based on the interface model shown in FIG. 21. This histogram represents the number of lithium atoms and iodine atoms included in the interface model shown in FIG. 21 along a predetermined crystal axis (here, the c-axis) in 25 bins. As shown in (a) of FIG. 22, this histogram includes regions where iodine atoms are present and regions where they are not, even in the reaction product region, making it difficult to accurately distinguish the reaction product region. Therefore, widening the bin width of the histogram is considered, but this reduces the resolution of the reaction product region, making it difficult to accurately distinguish the reaction product region.

[0127] Therefore, here, the output unit 13 smoothes the histogram shown in FIG. 22(a) by converting it into a Gaussian function with an appropriate standard deviation (here, σ = 1.2) (see FIG. 22(b)). Then, the output unit 13 calculates the ratio of the number of iodine atoms to the number of lithium atoms from the Gaussian function (see FIG. 22(c)). In FIG. 22(c), the solid line represents the ratio of the number of iodine atoms to the number of lithium atoms (hereinafter referred to as the "first ratio"), and the dashed line represents the ratio of the number of iodine atoms to the number of lithium atoms in the entire interface model (hereinafter referred to as the "second ratio"). The output unit 13 then estimates the range where the first ratio is lower than the second ratio as the reaction occurrence region. In the example shown in FIG. 22(c), the reaction occurrence region is in the range of c = [0.0, 0.08] and the range of c = [0.36, 1.0]. Therefore, the ratio of the reaction occurrence region to the entire interface model can be calculated to be approximately 0.75.

[0128] Furthermore, for example, the output unit 13 (in the process of outputting progress information) may estimate the reaction occurrence area by analyzing an image of an interface model such as that shown in Figure 21 using image recognition technology such as semantic segmentation.

[0129] In addition, for example, in the embodiment, the interface model is a model in which any one crystal plane of the crystal structure of the first solid material and any one crystal plane of the crystal structure of the second solid material are superimposed, but is not limited to this. Examples of the interface model are listed below.

[0130] Fig. 23 is a diagram showing an example of an interface model. In Fig. 23, "A1" is a figure representing the crystal structure of a first solid material on a two-dimensional plane, and [A2] is a figure representing the crystal structure of a second solid material on a two-dimensional plane. The same applies to Fig. 24 described below. As shown in Fig. 23(a) and Fig. 23(b), the interface model may be a model in which two crystal planes of a certain crystal structure overlap with crystal planes of another solid material.

[0131] FIG. 24 is a diagram showing another example of an interface model. In FIG. 24, "A3" is a figure representing the crystal structure of a third solid material in a two-dimensional plane, and [A4] is a figure representing the crystal structure of a fourth solid material in a two-dimensional plane. As shown in FIGS. 24(a), 24(b), and 24(c), the interface model may be a model in which the crystal planes of three or more solid materials are superimposed. Also, as shown in FIG. 24(b), the interface model may be a model in which the crystal planes of two or more other solid materials overlap on the crystal plane of a certain solid material. Also, as shown in FIG. 24(c), the interface model may be a model in which the crystal planes of two different solid materials overlap on each of two crystal planes of a certain solid material.

[0132] Fig. 25 is a diagram showing yet another example of an interface model. In Fig. 25, each tetrahedron represents a crystal structure of a different solid-state material. As shown in Fig. 25(a) and Fig. 25(c), the interface model may be a three-dimensional model in which the crystal planes of multiple solid-state materials are superimposed.

[0133] In the above embodiment, the information processing system is configured with the acquisition unit 11, the processing unit 12, and the output unit 13, but is not limited to this. For example, in the above embodiment, the information processing system may be configured with the display control unit 30 and the display unit 3, as shown by "100A" in Fig. 1 .

[0134] In the above-described embodiments, each component may be configured with dedicated hardware, or may be realized by executing a software program suitable for each component. Each component may be realized by a program execution unit such as a CPU (Central Processing Unit) or a processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory.

[0135] The following cases are also included in this disclosure:

[0136] (1) The at least one device is specifically a computer system comprising a microprocessor, a ROM (Read Only Memory), a RAM (Random Access Memory), a hard disk unit, a display unit, a keyboard, a mouse, etc. A computer program is stored in the RAM or hard disk unit. The at least one device achieves its function when the microprocessor operates in accordance with the computer program. Here, the computer program is composed of a combination of multiple instruction codes that indicate commands to a computer to achieve a predetermined function.

[0137] (2) Some or all of the components constituting at least one of the above devices may be configured as a single system LSI (Large Scale Integration). A system LSI is an ultra-multifunctional LSI manufactured by integrating multiple components on a single chip, and specifically, is a computer system configured to include a microprocessor, ROM, RAM, etc. A computer program is stored in the RAM. The system LSI achieves its functions by the microprocessor operating in accordance with the computer program.

[0138] (3) Some or all of the components constituting at least one of the above devices may be configured as an IC card or a standalone module that can be attached to the device. The IC card or module is a computer system configured from a microprocessor, ROM, RAM, etc. The IC card or module may include the above-mentioned ultra-multifunctional LSI. The IC card or module achieves its functions when the microprocessor operates in accordance with a computer program. This IC card or module may be tamper-resistant.

[0139] (4) The present disclosure may be embodied as the methods described above, a computer program for implementing these methods on a computer, or a digital signal comprising the computer program.

[0140] The present disclosure may also be a computer program or a digital signal recorded on a computer-readable recording medium, such as a flexible disk, a hard disk, a CD (Compact Disc)-ROM, a DVD, a DVD-ROM, a DVD-RAM, a BD (Blu-ray (registered trademark) Disc), or a semiconductor memory, or a digital signal recorded on such a recording medium.

[0141] The present disclosure may also be applied to transmitting a computer program or a digital signal via a telecommunications line, a wireless or wired communication line, a network such as the Internet, or data broadcasting.

[0142] Furthermore, the program or digital signal may be recorded on a recording medium and transferred, or the program or digital signal may be transferred via a network or the like, so that the program or digital signal may be implemented by another independent computer system.

[0143] The present disclosure, for example, has the effect of appropriately assisting a user in predicting the reaction of two or more solid materials, and can be used in a computer device or system for displaying information related to the prediction process.

[0144] REFERENCE SIGNS LIST 11 Acquisition unit 12 Processing unit 13 Output unit 14 Storage unit 2 Input unit 3 Display unit 30 Display control unit 100, 100A Information processing system

Claims

1. An information processing method executed by a computer, comprising: acquiring interface model information indicating an interface model for two or more solid materials; executing a simulation of a reaction of the two or more solid materials based on the acquired interface model information; and outputting progress information indicating the progress of the reaction based on reaction information regarding the reaction obtained by the simulation.

2. The information processing method according to claim 1, wherein the process of outputting the progress information includes outputting the progress information including characteristic information indicating characteristics of a structure generated by the reaction.

3. The information processing method according to claim 1 or 2, wherein the two or more solid materials are a first solid material and a second solid material, and the process of acquiring the interface model information comprises acquiring first structural model information indicating a first structural model for a structure of the first solid material and second structural model information indicating a second structural model for a structure of the second solid material, and generating the interface model by combining the first structural model and the second structural model based on the acquired first structural model information and second structural model information.

4. The information processing method according to claim 1 or 2, wherein the simulation is a simulation using a molecular dynamics method, and the reaction information includes first data indicating the interface model corresponding to a start time of the simulation, and second data indicating the interface model corresponding to an end time of the simulation.

5. The information processing method of claim 4, wherein the process of outputting the progress information includes outputting the progress information including information indicating that the reaction has occurred when the interface model represented by the second data includes a reaction occurrence region in which atoms contained in each of the two or more solid materials are mixed, and outputting the progress information including information indicating that the reaction has not occurred when the interface model represented by the second data does not include the reaction occurrence region.

6. The information processing method according to claim 4, wherein the process of outputting the progress information comprises calculating a rate of the reaction based on the difference between the start time and the end time, and outputting the progress information including the calculated rate of the reaction.

7. An information processing method according to claim 1 or 2, wherein the simulation is a simulation using a molecular dynamics method, and the process of outputting the progress information includes outputting a radial distribution function of one or more atoms included in the interface model during the execution of the simulation as characteristic information indicating characteristics of the structure generated by the reaction included in the progress information.

8. The information processing method according to claim 7, wherein in the process of outputting the progress information, a time at which a predetermined peak contained in the radial distribution function disappears at the start time of the simulation is estimated to be the end time of the reaction, and the progress information including the estimated end time of the reaction is output.

9. The information processing method of claim 8, wherein the process of outputting the progress information calculates the volume of a reaction product produced by the reaction based on the coordination number of the atoms included in the interface model with respect to a specified crystal axis, and outputs the progress information including the calculated volume of the reaction product.

10. The information processing method of claim 9, wherein the process of outputting the progress information comprises: calculating a reaction time indicating the time from when the reaction starts to when it ends based on the difference between the start time and the end time; calculating a rate of the reaction based on the calculated reaction time and the volume of the reaction product; and outputting the progress information including the calculated rate of the reaction.

11. An information processing method as described in claim 1 or 2, wherein the process of performing the simulation comprises: performing a structural relaxation calculation of the interface model based on the acquired interface model information; and performing the simulation on the interface model after the structural relaxation calculation has been performed.

12. An information processing system comprising: a display control unit that causes a first image for accepting input of first solid material information indicating a first solid material and second solid material information indicating a second solid material to be displayed on the display unit, after which a second image showing progress information indicating a degree of progress of a reaction between the first solid material and the second solid material is displayed on the display unit, the progress information being generated based on the input first solid material information and the second solid material information.

13. The information processing system of claim 12, wherein the display control unit further displays a third image on the display unit indicating first interface model information generated based on the input first solid material information and second solid material information, and the first interface model information indicates a first interface model including a boundary region between the first structure and the second structure, which is generated by contact between the first solid material having a first structure including a plurality of first atoms and the second solid material having a second structure including a plurality of second atoms.

14. The information processing system of claim 13, wherein the display control unit further causes the display unit to display a fourth image that accepts input of calculation method information indicating a calculation method that can be executed on the first interface model, and further causes the display unit to display a fifth image that indicates second interface model information generated based on the input calculation method information.

15. A program that causes a computer to execute the steps of: acquiring interface model information indicating an interface model for two or more solid materials; executing a simulation of a reaction of the two or more solid materials based on the acquired interface model information; and outputting progress information indicating a degree of progress of the reaction based on reaction information regarding the reaction obtained by the simulation, wherein each of the two or more solid materials includes a plurality of atoms.

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