Information processing device, information processing method, and information processing program

Abstract

The present invention improves calculation accuracy when calculating an aggregate. This information processing device comprises: a first acquisition unit that acquires a basic model when calculating an aggregate; a binding determination unit that determines the presence or absence of binding between atoms in the basic model; a constraint condition setting unit that sets a constraint condition between atoms determined to be bound; and a second acquisition unit that acquires an initial model, which is an initial structure model for calculating the aggregate, by instructing a relaxation calculation by disposing, in a calculation space, a relaxation calculation model in which the basic model is disposed in plurality and the constraint condition is set between atoms.

Description

Information processing device, information processing method, and information processing program

[0001] The present disclosure relates to an information processing device, an information processing method, and an information processing program.

[0002] In the case of performing calculations on aggregates (calculation of the reaction of aggregates, calculation of the physical properties of aggregates, etc.), relaxation calculations are performed when generating the initial structure of the model of the aggregate to be calculated (referred to as the "initial model"), because performing relaxation calculations makes it possible to generate an initial model with less arbitrariness.

[0003] JP 2023-178831 A JP 2023-63964 A

[0004] On the other hand, in large-scale calculations of systems that involve aggregates containing three or more molecules, or aggregates including organic polymers, crystals, amorphous materials, etc., if bonds are not described in the interactions between atoms (only interactions between atoms or between atoms and electrons are taken into account), unintended reactions (unintended recombination or scission of bonds between atoms) may occur during relaxation calculations. As a result, when calculating an aggregate using the generated initial model, appropriate calculation results may not be obtained.

[0005] The present disclosure improves the accuracy of calculations when performing aggregation calculations.

[0006] A first aspect of the present disclosure is an information processing device comprising: a first acquisition unit that acquires a basic model when performing calculations on an aggregate; a bond determination unit that determines whether or not there is a bond between each atom in the basic model; a constraint condition setting unit that sets constraint conditions between atoms that are determined to be bonded; and a second acquisition unit that acquires an initial model, which is a model of an initial structure for performing calculations on the aggregate, by instructing the device to perform a relaxation calculation by placing a relaxation calculation model in a calculation space in which a plurality of the basic models are arranged and in which the constraint conditions are set between atoms.

[0007] A second aspect of the present disclosure is the information processing device according to the first aspect, wherein the bond determination unit calculates a distance between each atom in the basic model, and determines whether or not a bond exists between each atom based on the calculated distance and a cutoff radius.

[0008] A third aspect of the present disclosure is the information processing device according to the first aspect, wherein the bond determination unit determines that an atom located within a cutoff sphere relative to an atom of interest is bonded to the atom of interest, or determines that atoms whose cutoff spheres overlap or touch each other are bonded.

[0009] A fourth aspect of the present disclosure is the information processing device according to the first aspect, wherein the constraint condition is a parameter for calculating a force acting between atoms determined to be bonded.

[0010] A fifth aspect of the present disclosure is the information processing device according to the fourth aspect, wherein the forces acting between the atoms include a force acting in a direction to decrease the distance between the atoms when the distance between the atoms increases in a relaxation calculation, and a force acting in a direction to increase the distance between the atoms when the distance between the atoms decreases.

[0011] A sixth aspect of the present disclosure is the information processing device according to the fifth aspect, wherein the parameters include a distance in an equilibrium state between the atoms determined to be bonded and a spring constant between the atoms determined to be bonded.

[0012] A seventh aspect of the present disclosure is the information processing device according to the fourth aspect, wherein the forces acting between the atoms include a force acting in a direction that decreases the distance between the atoms when the distance between the atoms increases in a relaxation calculation.

[0013] An eighth aspect of the present disclosure is an information processing device according to the seventh aspect, wherein the parameters include a distance in an equilibrium state between atoms determined to be bonded and a rubber spring constant between the atoms determined to be bonded, and the rubber spring constant is zero when the distance between the atoms is equal to or less than the distance in the equilibrium state, and is equal to or greater than a predetermined threshold when the distance between the atoms is greater than the distance in the equilibrium state.

[0014] A ninth aspect of the present disclosure is an information processing device according to the fifth or seventh aspect, further comprising a stable structure calculation unit that calculates a stable structure of the basic model, and the distance between the atoms in an equilibrium state is calculated based on the distance between atoms that are determined to be bonded, among the distances between each atom when the stable structure of the basic model is calculated.

[0015] A tenth aspect of the present disclosure is the information processing device according to the first aspect, wherein a molecular dynamics method is used for the relaxation calculation.

[0016] An eleventh aspect of the present disclosure is an information processing device according to the first aspect, further comprising a third acquisition unit that acquires a predetermined calculation result by instructing the device to perform a calculation of the aggregate using the initial model.

[0017] A twelfth aspect of the present disclosure is an information processing method, wherein a computer executes the following steps when calculating an aggregate: acquiring a basic model; determining whether or not there is a bond between each atom in the basic model; setting constraint conditions between atoms determined to be bonded; and acquiring an initial model, which is a model of an initial structure for calculating the aggregate, by instructing a relaxation calculation to be performed by arranging a relaxation calculation model in a calculation space in which a plurality of the basic models are arranged and in which the constraint conditions are set between atoms.

[0018] A thirteenth aspect of the present disclosure is an information processing program that causes a computer to execute the following steps when calculating an aggregate: acquiring a basic model; determining whether or not there is a bond between each atom in the basic model; setting constraint conditions between atoms that are determined to be bonded; and acquiring an initial model, which is a model of an initial structure for calculating the aggregate, by instructing a relaxation calculation model in which a plurality of the basic models are arranged and the constraint conditions are set between atoms to be arranged in a calculation space and to perform a relaxation calculation.

[0019] According to the present disclosure, it is possible to improve the calculation accuracy when calculating aggregates.

[0020] FIG. 1 is a diagram illustrating an example of the functional configuration of an information processing device. FIG. 2 is a diagram illustrating an example of the hardware configuration of an information processing device. FIG. 3 is a diagram illustrating a specific example of basic model acquisition processing by a basic model acquisition unit. FIG. 4 is a diagram illustrating a specific example of stable structure calculation processing by a stable structure calculation unit. FIG. 5 is a diagram illustrating a specific example of bond determination processing by a bond determination unit. FIG. 6 is a diagram illustrating a specific example of relaxation calculation model creation processing by a relaxation calculation model creation unit. FIG. 7 is a diagram illustrating a specific example of constraint condition setting processing by a constraint condition setting unit. FIG. 8A is a first diagram illustrating a specific example of initial model acquisition processing by an initial model acquisition unit of a comparative example. FIG. 8B is a second diagram illustrating a specific example of initial model acquisition processing by an initial model acquisition unit of a comparative example. FIG. 9 is a diagram illustrating a specific example of initial model acquisition processing by an initial model acquisition unit. FIG. 10 is a flowchart showing the flow of aggregate calculation processing by an information processing device.

[0021] Hereinafter, each embodiment will be described with reference to the accompanying drawings. In this specification and drawings, components having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0022] [First embodiment] <Functional configuration of information processing device> First, the functional configuration of an information processing device according to the first embodiment will be described. Fig. 1 is a diagram showing an example of the functional configuration of an information processing device. An information processing device 100 according to the first embodiment has an information processing program installed therein, and by executing the information processing program, the information processing device 100 functions as each unit shown in Fig. 1.

[0023] Specifically, the information processing device 100 functions as a molecular dynamics calculation unit 110. The information processing device 100 functions as a basic model acquisition unit 121, a stable structure calculation unit 122, a bond determination unit 123, a relaxation calculation model creation unit 124, a constraint condition setting unit 125, and an initial model acquisition unit 126. The information processing device 100 functions as a calculation result acquisition unit 130.

[0024] The molecular dynamics calculation unit 110 performs molecular dynamics calculation, which is an example of calculation in which bonds are not described in the interactions between atoms (only interactions between atoms or interactions between atoms and electrons are taken into account). Specifically, the molecular dynamics calculation unit 110 performs relaxation calculation using the molecular dynamics method on a relaxation calculation model (described in detail below) under set constraint conditions, and generates an initial state (referred to as an initial model) of a model of the aggregate to be calculated. The molecular dynamics calculation unit 110 performs calculations using the molecular dynamics method on the generated initial model, thereby calculating the reaction of the aggregate, calculating the properties of the aggregate, and outputting the calculation results.

[0025] The basic model acquisition unit 121 is an example of a first acquisition unit, and acquires the basic model by receiving, from a user, information indicating a basic model to be used in creating a relaxation calculation model. The relaxation calculation model is a model that represents the molecular structure of the material contained in the aggregate, and is created based on the basic model. As described above, an initial model is generated from the relaxation calculation model, and molecular dynamics calculations are performed on the generated initial model to calculate the reaction of the aggregate, calculate the properties of the aggregate, and so on. Therefore, the basic model can be said to be a model for performing calculations on the aggregate.

[0026] If the molecular structure of the basic model acquired by the basic model acquisition unit 121 is an energetically unstable structure, the stable structure calculation unit 122 converts it into an energetically stable structure.

[0027] The bond determination unit 123 determines the presence or absence of bonds between atoms for a basic model having an energetically stable structure and generates bond information. The method by which the bond determination unit 123 determines the presence or absence of bonds is arbitrary, and for example, the presence or absence of bonds may be determined based on a cutoff radius. Alternatively, the presence or absence of bonds may be determined by a user.

[0028] The relaxation calculation model creation unit 124 receives instructions from a user regarding the molecular arrangement of a basic model having an energetically stable structure and for which the presence or absence of bonds between atoms has been determined. The relaxation calculation model creation unit 124 creates a relaxation calculation model by arranging multiple basic models based on the instructed molecular arrangement. The relaxation calculation model creation unit 124 inputs the created relaxation calculation model to the molecular dynamics calculation unit 110.

[0029] The constraint condition setting unit 125 sets constraint conditions for the relaxation calculation model in order to avoid the occurrence of unintended reactions when the created relaxation calculation model is placed in the calculation space and relaxation calculation is performed.

[0030] An unintended reaction refers to, for example, a bond rearrangement that occurs when relaxation calculation models for different materials are placed in the calculation space and a relaxation calculation is performed. More specifically, an unintended reaction refers to: - some of the atoms that belonged to the molecules of one relaxation calculation model breaking their bonds with other atoms that belong to the molecules of that one relaxation calculation model, and - the atoms whose bonds have been broken move toward the molecules of the other relaxation calculation model and bond with atoms that belong to the molecules of that other relaxation calculation model, resulting in changes in the molecular structure of one relaxation calculation model and the molecular structure of the other relaxation calculation model.

[0031] Alternatively, an unintended reaction refers to, for example, the breaking of a bond that constitutes a molecule when a relaxation calculation model for a material consisting of one type of molecule is placed in the calculation space and a relaxation calculation is performed. More specifically, an unintended reaction refers to the following: - The breaking of a bond that constitutes one molecule, resulting in the generation of two or more molecules.

[0032] The constraint condition setting unit 125 sets constraint conditions so that a force acts between atoms that are determined to be bonded by the bond determination unit 123, among the atoms belonging to the molecules of the relaxation calculation model, thereby preventing the above-mentioned bond recombination or breaking from occurring in the relaxation calculation.

[0033] The initial model acquisition unit 126 is an example of a second acquisition unit, and instructs the molecular dynamics calculation unit 110 to place a relaxation calculation model in which constraint conditions are set between atoms determined to be bonded in the calculation space and perform a relaxation calculation.

[0034] The molecular dynamics calculation unit 110 performs a relaxation calculation by, for example, dispersing one relaxation calculation model in a calculation space and arranging the other relaxation calculation model in the calculation space, and adsorbing one relaxation calculation model to the other relaxation calculation model under a predetermined temperature and a predetermined pressure. As a result, the molecular dynamics calculation unit 110 can generate a model in which one relaxation calculation model is adsorbed to the other relaxation calculation model as an initial model, which is a model of an initial structure for performing an aggregate calculation.

[0035] The initial model acquisition unit 126 acquires the initial model generated by the molecular dynamics calculation unit 110 and notifies the user, for example. The initial model acquisition unit 126 may remove from the initial model the constraint conditions that were set before the relaxation calculation was performed, and then notify the user.

[0036] The calculation result acquisition unit 130 is an example of a third acquisition unit, and receives an instruction to calculate an aggregate from the user when the user is notified that an initial model for calculating an aggregate has been acquired by the initial model acquisition unit 126. The calculation result acquisition unit 130 notifies the molecular dynamics calculation unit 110 of the received instruction to calculate an aggregate.

[0037] As a result, the molecular dynamics calculation unit 110 performs calculations using molecular dynamics on the initial model in the calculation space at a specified temperature and pressure, and outputs calculation results of the reaction of the aggregate, calculation results of the properties of the aggregate, etc.

[0038] When the molecular dynamics calculation unit 110 outputs the calculation results of the reaction of the aggregate, the calculation results of the properties of the aggregate, etc., the calculation result acquisition unit 130 notifies the user of the output calculation results.

[0039] <Hardware Configuration of Information Processing Apparatus> Next, a description will be given of the hardware configuration of the information processing apparatus 100 according to the first embodiment. Fig. 2 is a diagram showing an example of the hardware configuration of the information processing apparatus.

[0040] 2, the information processing device 100 includes a processor 201, a memory 202, an auxiliary storage device 203, an interface device 204, a communication device 205, and a drive device 206. The hardware components of the information processing device 100 are connected to each other via a bus 207.

[0041] The processor 201 has various computing devices such as a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc. The processor 201 executes various programs (for example, information processing programs) by reading them into the memory 202.

[0042] The memory 202 has a main storage device such as a read-only memory (ROM) or a random access memory (RAM). The processor 201 and the memory 202 form a so-called computer, and the computer realizes the above-mentioned functions by the processor 201 executing various programs read onto the memory 202.

[0043] The auxiliary storage device 203 stores various programs and various data used when the processor 201 executes the programs.

[0044] The interface device 204 is a connection device for connecting an operation device 211, which is an example of a user interface device, and a display device 212. The communication device 205 is a communication device for communicating with an external device via a network (not shown).

[0045] The drive device 206 is a device for loading a recording medium 213. The recording medium 213 here includes media that record information optically, electrically, or magnetically, such as a CD-ROM, a flexible disk, a magneto-optical disk, etc. The recording medium 213 may also include semiconductor memory that records information electrically, such as a ROM, a flash memory, etc.

[0046] The various programs to be installed in the auxiliary storage device 203 are installed, for example, by setting the distributed recording medium 213 in the drive device 206 and reading the various programs recorded on the recording medium 213 by the drive device 206. Alternatively, the various programs to be installed in the auxiliary storage device 203 may be installed when downloaded from a network via the communication device 205.

[0047] <Details of Processing by Basic Model Acquisition Unit> Next, a description will be given of details of the basic model acquisition processing by the basic model acquisition unit 121. Fig. 3 is a diagram showing a specific example of the basic model acquisition processing by the basic model acquisition unit.

[0048] 3 , the basic model acquisition unit 121 receives input from a user as information indicating a basic model used to create a relaxation calculation model, such as information indicating the types of atoms belonging to molecules of the material contained in the aggregate, information indicating the molecular structure of the material contained in the aggregate, etc. In this way, the basic model acquisition unit 121 acquires, for example, a basic model 300.

[0049] <Details of Processing by Stable Structure Calculation Unit> Next, a description will be given of details of stable structure calculation processing by the stable structure calculation unit 122. Fig. 4 is a diagram showing a specific example of stable structure calculation processing by the stable structure calculation unit.

[0050] 4 , the stable structure calculation unit 122 converts the molecular structure of the basic model 300 acquired by the basic model acquisition unit 121 into an energetically stable structure, thereby generating a stable structure basic model 400. The conversion method used by the stable structure calculation unit 122 is arbitrary, and may be the conversion method used by the molecular dynamics calculation unit 110 when performing a relaxation calculation, or the conversion method used by the molecular dynamics calculation unit 110 when performing an aggregate calculation.

[0051] <Details of Processing by Merger Determination Unit> Next, a description will be given of details of the merger determination process by the merger determination unit 123. Fig. 5 is a diagram showing a specific example of the merger determination process by the merger determination unit.

[0052] 5, when the stable structure calculation unit 122 generates a basic model 400 of a stable structure, the bond determination unit 123 determines the presence or absence of a bond between each atom in the basic model 400 of the stable structure based on a cutoff radius specified in advance by a user. In Fig. 5, symbols 500a and 500b respectively indicate different determination methods for determining the presence or absence of a bond.

[0053] According to reference numeral 500a, the bond determination unit 123 calculates a cutoff sphere 511 for an atom 510 (atom of interest) based on a cutoff radius 501 previously specified by a user. The bond determination unit 123 determines that atoms 520 and 530 that are included within the calculated cutoff sphere 511 (i.e., the distance between them and the atom of interest is shorter than the cutoff radius) are bonded to the atom 510 (atom of interest). On the other hand, the bond determination unit 123 determines that atom 540 that is not included within the calculated cutoff sphere 511 (i.e., the distance between them and the atom of interest is equal to or greater than the cutoff radius) is not bonded to the atom 510 (atom of interest).

[0054] According to reference numeral 500b, the bond determination unit 123 calculates cutoff spheres 511, 521, 531, and 541 for each of the atoms 510, 520, 530, and 540 based on a cutoff radius previously specified by a user. The bond determination unit 123 determines that the cutoff spheres 511, 521, 531, and 541 calculated for each of the atoms 510, 520, 530, and 540 bond atoms that overlap with each other (i.e., atoms whose interatomic distance is shorter than the sum of the cutoff radii of the atoms), or atoms that contact each other (i.e., atoms whose interatomic distance is equal to the sum of the cutoff radii of the atoms). On the other hand, the bond determination unit 123 determines that the cutoff spheres 511, 521, 531, and 541 calculated for the respective atoms 510, 520, 530, and 540 are not bonded to each other if: - Atoms that do not overlap and are not in contact with each other (i.e., atoms whose interatomic distance is greater than the sum of the cutoff radii of each atom).

[0055] The bond determination unit 123 generates bond information describing bonds between atoms by determining whether or not bonds exist between the atoms using the determination method shown by reference numeral 500 a or 500 b. In Fig. 5, reference numeral 550 denotes an example of bond information describing bonds between atoms generated by the bond determination unit 123 for the basic model 400.

[0056] The example of reference numeral 550 shows a state in which the atom ID indicating carbon (C) is "3", the atom IDs indicating hydrogen (H) are "1" and "2", and the bonds between atoms are described as Bond1-3, Bond2-3.

[0057] <Details of Processing by Relaxation Calculation Model Creating Unit> Next, a description will be given of details of the relaxation calculation model creating process by the relaxation calculation model creating unit 124. Fig. 6 is a diagram showing a specific example of the relaxation calculation model creating process by the relaxation calculation model creating unit.

[0058] 6 , the relaxation calculation model creation unit 124 receives a molecular configuration input from a user for a basic model 400 of a stable structure for which the presence or absence of interatomic bonds has been determined. The relaxation calculation model creation unit 124 prepares a plurality of basic models 400 of a stable structure for which the presence or absence of interatomic bonds has been determined (see reference numeral 610), and creates a relaxation calculation model 620 by arranging the plurality of basic models based on the received molecular configuration. The relaxation calculation model creation unit 124 inputs the created relaxation calculation model 620 to the molecular dynamics calculation unit 110.

[0059] The relaxation calculation model creation unit 124 newly generates bonding information describing interatomic bonds for the created relaxation calculation model 620. This is because, when creating the relaxation calculation model 620, a plurality of basic models are arranged, and therefore it is necessary to reassign atomic IDs that are different from those when the bond determination unit 123 generates bonding information for the basic models that are single molecules.

[0060] <Details of Processing by Constraint Condition Setting Unit> Next, a description will be given of details of the constraint condition setting processing by the constraint condition setting unit 125. Fig. 7 is a diagram showing a specific example of the constraint condition setting processing by the constraint condition setting unit.

[0061] As shown in FIG. 7, the constraint condition setting unit 125 includes a bond distance acquisition unit 701 , an equilibrium position determination unit 702 , and a spring constant determination unit 703 .

[0062] The bond distance acquisition unit 701 acquires bond distances between atoms in the relaxation calculation model 620. Note that the method of acquiring bond distances by the bond distance acquisition unit 701 is arbitrary. As described above, the molecular structure of the basic model 400 included in the relaxation calculation model 620 is converted into an energetically stable structure. Therefore, the bond distance acquisition unit 701 may acquire bond distances between atoms in the relaxation calculation model 620 by calculating distances between atoms that are determined to be bonded in the relaxation calculation model 620. Alternatively, a user may define general bond distances between atoms in an energetically stable structure in advance, and the bond distance acquisition unit 701 may acquire the defined bond distances between general atoms.

[0063] The equilibrium position determination unit 702 determines the distance in the equilibrium state between atoms determined to be bonded in the relaxation calculation model 620 (equilibrium position r ０ Specifically, the equilibrium position determination unit 702 determines the distance in the equilibrium state between atoms determined to be bonded in the relaxation calculation model 620 (the equilibrium position r ０ ) is determined to be equal to or less than the bond distance acquired by the bond distance acquisition unit 701.

[0064] Alternatively, the equilibrium position determination unit 702 may determine the distance in the equilibrium state between atoms determined to be bonded in the relaxation calculation model 620 (equilibrium position r ０ ) is set to be longer than the bond distance acquired by the bond distance acquisition unit 701, the bond distance is set to be equal to or less than a predetermined upper limit. The predetermined upper limit here is, for example, the second nearest neighbor atomic distance. The second nearest neighbor atomic distance refers to the distance between a certain atom and the atom next to the first nearest neighbor atom, with a certain atom as the center. The first nearest neighbor atoms refer to a group of atoms that are bonded to each other.

[0065] The spring constant determination unit 703 determines a spring constant k between atoms determined to be bonded in the relaxation calculation model 620. The spring constant determination unit 703 determines a predetermined constant value as the spring constant k. Alternatively, the spring constant determination unit 703 determines a predetermined different value as the spring constant k for each atom determined to be bonded in the relaxation calculation model 620. Note that the spring constant determination unit 703 determines a value that will not cause bond recombination or severance when relaxation calculation is performed as the spring constant k.

[0066] The constraint condition setting unit 125 determines the distance in the equilibrium state between the atoms determined to be bonded by the equilibrium position determining unit 702 (equilibrium position r ０ ) and the spring constant k determined by the spring constant determination unit 703, and the parameters including the above are notified to the molecular dynamics calculation unit 110 as constraint conditions.

[0067] As a result, when the relaxation calculation model 620 is placed in the calculation space and a relaxation calculation is performed, the molecular dynamics calculation unit 110 calculates F=k×(r−r) between atoms that are determined to be bonded. ０ ) (r is the distance between atoms determined to be bonded). That is, when performing relaxation calculations by placing the relaxation calculation model 620 in the calculation space, the molecular dynamics calculation unit 110 can apply a force in the direction that reduces the distance between atoms determined to be bonded, if the distance between atoms increases, and if the distance between atoms decreases, apply a force in the direction that increases the distance between atoms.

[0068] 7 shows the case where constraint conditions are set for a spring model, but constraint conditions for a rubber model may also be set. In the case of a rubber model, the constraint condition setting unit 125 sets the following: The distance in the equilibrium state between atoms determined to be bonded, as determined by the equilibrium position determining unit 702 (equilibrium position r ０ ) and the spring constant k′ of the rubber determined by the spring constant determination unit 703, and the parameters including the above are notified to the molecular dynamics calculation unit 110 as constraint conditions.

[0069] As a result, when the relaxation calculation model 620 is placed in the calculation space and a relaxation calculation is performed, the molecular dynamics calculation unit 110 calculates F=k′×(r−r ０ ) can be applied (r is the distance between the atoms that are determined to be bonded). However, k' is determined as r≦r ０ (when the distance between atoms is equal to or less than the equilibrium distance), and ０ (when the distance between atoms is greater than the distance in the equilibrium state), the value is equal to or greater than a predetermined threshold.

[0070] As a result, when the molecular dynamics calculation unit 110 places the relaxation calculation model 620 in the calculation space and performs a relaxation calculation, it can apply a force to atoms determined to be bonded in a direction that reduces the distance between the atoms only when the distance between the atoms increases.

[0071] <Details of Processing by Initial Model Acquisition Unit> Next, the details of the initial model acquisition process by the initial model acquisition unit 126 will be described. Here, an example will be described in which two types of materials are included in the aggregate. One of the materials is glycerin (C ３ H ８ O ３ ) and the other material is magnesium oxide (MgO).

[0072] The molecular dynamics calculation unit 110 generates an initial model by dispersing glycerin on magnesium oxide crystals, then applying a downward force and performing a relaxation calculation to adsorb the glycerin onto the magnesium oxide crystals. Specifically, the molecular dynamics calculation unit 110 performs the relaxation calculation using: a relaxation calculation model created based on the molecular structure of glycerin, and a relaxation calculation model (herein referred to as a substrate model) created based on the molecular structure of magnesium oxide.

[0073] In the description, a specific example of the initial model acquisition process by the initial model acquisition unit of the comparative example will be first shown to clarify the difference from the initial model acquisition process by the initial model acquisition unit 126.

[0074] (1) Specific example of initial model acquisition processing by the initial model acquisition unit of the comparative example The initial model acquisition unit of the comparative example instructs the molecular dynamics calculation unit 110 to place a relaxation calculation model in which no constraint conditions are set between atoms in the calculation space and perform a relaxation calculation.

[0075] 8A is a diagram showing a specific example of an initial model acquisition process performed by the initial model acquisition unit of the comparative example. The example of FIG. 8A shows the state in the calculation space at each time acquired by the initial model acquisition unit of the comparative example by performing a relaxation calculation on an NVT ensemble using Berendsen thermostat under the following conditions: temperature: 80°C, time step: 1.0 [fs], downward force: 0.02 [eV / Å], and constraint: none. However, the interactions between atoms were described using a neural network potential.

[0076] 8A , reference numeral 801 indicates a state in which the relaxation calculation model is dispersed with the substrate model placed in the calculation space. Reference numeral 802 indicates a state in which the relaxation calculation model is attached to the substrate model by applying a downward force. Reference numeral 803 indicates a state in which an initial model is generated by removing the downward force.

[0077] As indicated by the reference numeral 803, when no constraint conditions are set, on the surface (interface) of the substrate model in a state in which the relaxation calculation model is adsorbed onto the substrate model, the molecular structures of the relaxation calculation model and the substrate model each change due to the following: Some of the O-H bonds of the relaxation calculation model are broken, and some of the H atoms that belonged to the molecules of the relaxation calculation model move toward the molecules of the substrate model, and The migrated H atoms bond with O atoms that belong to the molecules of the substrate model. In other words, an unintended reaction (unintended recombination or breaking of bonds between atoms) occurs during the relaxation calculation.

[0078] 8B is a second diagram showing a specific example of the initial model acquisition process by the initial model acquisition unit of the comparative example, and shows an enlarged portion of the surface of the substrate model. In FIG. 8B, the dashed lines indicate the OH bonds of the relaxation calculation model. In FIG. 8B, the arrows indicate that the OH bonds are broken at the two O atoms at the bottom of the glycerin skeleton shown by the dashed lines, and the H atoms at the ends of the OH bonds are bonded to the O atoms belonging to the molecules of the substrate model, respectively.

[0079] (2) Specific example of initial model acquisition process by initial model acquisition unit The initial model acquisition unit 126 instructs the molecular dynamics calculation unit 110 to place a relaxation calculation model in which constraint conditions are set between atoms in the calculation space and perform a relaxation calculation.

[0080] 9 is a diagram showing a specific example of the initial model acquisition process by the initial model acquisition unit 126. The example in Fig. 9 shows the state in the calculation space at each time acquired by the initial model acquisition unit 126 by performing a relaxation calculation under the following conditions: temperature: 80°C, time step: 1.0 [fs], downward force: 0.02 [eV / Å], constraint condition: present, and spring constant: 5 [eV / Å].

[0081] 9, reference numeral 901 indicates a state in which the relaxation calculation model is dispersed with the substrate model placed in the calculation space. Reference numeral 902 indicates a state in which the relaxation calculation model is attached to the substrate model by applying a downward force. Reference numeral 903 indicates a state in which an initial model is generated by removing the downward force.

[0082] As shown by the reference numeral 903, when constraint conditions are set, some of the O-H bonds of the relaxation calculation model are not broken at the surface (interface) of the substrate model when the relaxation calculation model is adsorbed onto the substrate model. Therefore, some of the H atoms belonging to the molecules of the relaxation calculation model do not move toward the molecules of the substrate model, and the moved H atoms do not bond with O atoms belonging to the molecules of the substrate model. In other words, it is possible to avoid unintended reactions (unintended recombination or breaking of bonds between atoms) occurring during relaxation calculations. As a result, it is possible to generate an appropriate initial model with a uniform interface.

[0083] <Flow of Aggregate Calculation Processing> Next, a description will be given of the flow of aggregate calculation processing by the information processing device 100. Fig. 10 is a flowchart showing the flow of aggregate calculation processing by the information processing device.

[0084] In step S1001, the information processing device 100 receives information indicating a basic model for performing calculations on an aggregate from a user, and acquires the basic model.

[0085] In step S1002, the information processing device 100 converts the molecular structure of the basic model into an energetically stable structure.

[0086] In step S1003, the information processing device 100 determines whether or not there is a bond between atoms in the basic model of the stable structure.

[0087] In step S1004, the information processing device 100 prepares multiple basic models of stable structures for which the presence or absence of bonds between atoms has been determined, and creates a model for relaxation calculation by arranging the multiple basic models based on the molecular arrangement specified by the user.

[0088] In step S1005, the information processing apparatus 100 sets constraint conditions for the relaxation calculation model.

[0089] In step S1006, the information processing device 100 generates an initial model by placing the relaxation calculation model, in which constraint conditions are set between atoms, in the calculation space and performing a relaxation calculation using the molecular dynamics method. If necessary, the constraint conditions that were set before the relaxation calculation may be removed from the generated initial model.

[0090] In step S1007, the information processing device 100 performs calculations on the aggregate (calculation of the reaction of the aggregate, calculation of the properties of the aggregate, etc.) using the initial model, and outputs the calculation results.

[0091] <Summary> As is clear from the above explanation, the information processing device 100 according to the first embodiment: - acquires a basic model when performing calculations on an aggregate; - determines whether or not there is a bond between each atom in the basic model; - sets constraint conditions between atoms that are determined to be bonded; - acquires an initial model, which is a model of the initial structure when performing calculations on an aggregate, by issuing an instruction to perform a relaxation calculation by arranging, in the calculation space, a relaxation calculation model in which a plurality of basic models are arranged and constraint conditions are set between atoms.

[0092] In this way, in the information processing apparatus 100 according to the first embodiment, when a relaxation calculation model is placed in the calculation space and a relaxation calculation is performed, constraint conditions are set to prevent recombination or breaking of bonds. As a result, the information processing apparatus 100 according to the first embodiment can avoid the occurrence of unintended reactions in the relaxation calculation and generate an appropriate initial model.

[0093] As a result, according to the first embodiment, it is possible to improve the calculation accuracy when calculating the aggregate.

[0094] Second Embodiment In the above-described first embodiment, the bond determination unit 123 determines whether or not there is a bond between atoms, and then the relaxation calculation model creation unit 124 creates the relaxation calculation model. However, the relaxation calculation model creation unit 124 may create the relaxation calculation model before the bond determination unit 123 determines whether or not there is a bond between atoms. In other words, the bond determination unit 123 may determine whether or not there is a bond between atoms in the relaxation calculation model.

[0095] In the first embodiment, calculation using molecular dynamics is given as an example of calculation in which bonds are not described in the interactions between atoms (only interactions between atoms or interactions between atoms and electrons are taken into account), but other calculation methods may also be used. For example, first-principles calculations other than molecular dynamics may be used, or machine learning potential (MLP) may be used.

[0096] In the first embodiment, an example has been described in which an initial model in which glycerin is adsorbed to magnesium oxide is generated by a relaxation calculation. However, the initial model generated by the information processing device 100 is not limited to this.

[0097] For example, a relaxation calculation may be performed on a combination of an organic material and an inorganic material other than glycerin and magnesium oxide to generate an initial model having a uniform interface structure. Alternatively, an initial model having a structure filled with a low-molecular-weight material may be generated by the relaxation calculation. Alternatively, an initial model having an intercalation compound structure may be generated by the relaxation calculation. Alternatively, an initial model in which the arrangement of structural water is determined may be generated by the relaxation calculation.

[0098] In the first embodiment, the aggregate is described as including two types of materials, but may include only one type of material. For example, the information processing device 100 may generate an initial model having an optimal aggregate structure for one type of polymer by performing a relaxation calculation.

[0099] Furthermore, in the first embodiment, the information processing device 100 is described as being realized by one piece of hardware, but the information processing device 100 may be realized by a plurality of pieces of hardware.

[0100] The present invention is not limited to the configurations described in the above embodiments, but may be combined with other elements, etc. These aspects can be changed without departing from the spirit of the present invention, and can be appropriately determined depending on the application form.

[0101] This application claims priority based on Japanese Patent Application No. 2024-091533, filed on June 5, 2024, the entire contents of which are incorporated herein by reference.

[0102] 100: Information processing device 110: Molecular dynamics calculation unit 121: Basic model acquisition unit 122: Stable structure calculation unit 123: Bond determination unit 124: Relaxation calculation model creation unit 125: Constraint condition setting unit 126: Initial model acquisition unit 130: Calculation result acquisition unit 701: Bond distance acquisition unit 702: Equilibrium position determination unit 703: Spring constant determination unit

Claims

1. An information processing device having: a first acquisition unit that acquires a basic model when calculating an aggregate; a bond determination unit that determines whether or not there is a bond between each atom in the basic model; a constraint condition setting unit that sets constraint conditions between atoms that are determined to be bonded; and a second acquisition unit that acquires an initial model, which is a model of an initial structure for calculating the aggregate, by instructing the device to place a relaxation calculation model in which a plurality of the basic models are arranged and in which the constraint conditions are set between atoms in a calculation space and perform a relaxation calculation.

2. The information processing device according to claim 1, wherein the bond determination unit calculates the distance between each atom in the basic model, and determines whether or not a bond exists between each atom based on the calculated distance and a cutoff radius.

3. The information processing device according to claim 1, wherein the bond determination unit determines that an atom located within a cutoff sphere relative to the atom of interest is bonded to the atom of interest, or determines that atoms whose cutoff spheres overlap or touch each other are bonded.

4. The information processing device according to any one of claims 1 to 3, wherein the constraint conditions are parameters for calculating the force acting between atoms determined to be bonded.

5. The information processing device according to claim 4, wherein the forces acting between the atoms include a force that acts in a direction that decreases the distance between the atoms when the distance between the atoms increases, and a force that acts in a direction that increases the distance between the atoms when the distance between the atoms decreases.

6. The information processing device according to claim 5, wherein the parameters include a distance in an equilibrium state between atoms determined to be bonded and a spring constant between atoms determined to be bonded.

7. The information processing device according to claim 4, wherein the forces acting between the atoms include a force acting in a direction that decreases the distance between the atoms when the distance between the atoms increases in a relaxation calculation.

8. The information processing device of claim 7, wherein the parameters include a distance in an equilibrium state between atoms determined to be bonded and a rubber spring constant between the atoms determined to be bonded, and the rubber spring constant is zero when the distance between the atoms is equal to or less than the distance in the equilibrium state, and is greater than or equal to a predetermined threshold when the distance between the atoms is greater than the distance in the equilibrium state.

9. An information processing device according to claim 5 or 7, further comprising a stable structure calculation unit that calculates a stable structure of the basic model, and the distance between the atoms in an equilibrium state is calculated based on the distance between atoms that are determined to be bonded, among the distances between each atom when the stable structure of the basic model is calculated.

10. The information processing device according to any one of claims 1 to 9, wherein the relaxation calculation uses a molecular dynamics method.

11. The information processing device according to any one of claims 1 to 10, further comprising a third acquisition unit that acquires a predetermined calculation result by issuing an instruction to perform a calculation on the aggregate using the initial model.

12. An information processing method in which a computer executes the following steps when calculating an aggregate: obtaining a basic model; determining whether or not there is a bond between each atom in the basic model; setting constraint conditions between atoms determined to be bonded; and obtaining an initial model, which is a model of the initial structure for calculating the aggregate, by placing a relaxation calculation model in a calculation space in which a plurality of the basic models are arranged and in which the constraint conditions are set between atoms, and instructing the system to perform a relaxation calculation.

13. An information processing program for causing a computer to execute the following steps when calculating an aggregate: obtaining a basic model; determining whether or not there is a bond between each atom in the basic model; setting constraint conditions between atoms determined to be bonded; and obtaining an initial model, which is a model of the initial structure for calculating the aggregate, by instructing a relaxation calculation to be performed by arranging a relaxation calculation model in which a plurality of the basic models are arranged and the constraint conditions are set between atoms in a calculation space.

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