Information processing methods, information processing systems, and programs

Abstract

This invention provides an information processing method that can improve the efficiency of searching for crystal structures. [Solution] In the information processing method performed by the information processing device 100, elemental information da relating to two or more elements is acquired (step S10), and a first element set containing one or more elements and a second element set containing one or more elements are generated by classifying the two or more elements based on predetermined conditions (step S20), and a second crystal structure is generated by arranging one or more elements contained in the second element set in a first crystal structure composed of one or more elements contained in the first element set (steps S30, S40), and output information dc relating to the second crystal structure is output (step S50).

Description

[Technical Field]

[0001] This disclosure relates, for example, to a technique for performing processing related to the crystal structure of a material. [Background technology]

[0002] Conventionally, a material creation method has been proposed as an information processing method for searching for new crystal structures that realize desired material functions (see, for example, Patent Document 1). In this material creation method, first, the material creation apparatus generates a current generation set of crystal structures as an initial structure by randomly determining the coordinates of each lattice vector, atomic positions, etc. Random numbers are used for this determination. Then, the material creation apparatus generates the crystal structure of an inorganic material using this current generation set of crystal structures, a regression model, and a genetic algorithm. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2018-10428 [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the material creation method described in Patent Document 1 has the problem that it is difficult to efficiently search for the crystal structure.

[0005] This disclosure solves the above-mentioned problems and provides an information processing method that can improve the efficiency of searching for crystal structures. [Means for solving the problem]

[0006] To solve the above problems, an information processing method according to an aspect of the present disclosure is an information processing method executed by an information processing apparatus, which acquires element information regarding two or more types of elements, and classifies the two or more types of elements based on a predetermined condition to generate a first element set including one or more types of elements and a second element set including one or more types of elements, arranges the one or more types of elements included in the second element set in a first crystal structure constituted by using the one or more types of elements included in the first element set to generate a second crystal structure, and outputs output information regarding the second crystal structure.

[0007] These general or specific aspects may be implemented in a system, an integrated circuit, or a recording medium such as a computer-readable CD-ROM, or may be implemented by any combination of an apparatus, a system, a method, an integrated circuit, a computer program, and a recording medium. The recording medium may also be a non-transitory recording medium.

Advantages of the Invention

[0008] According to the present disclosure, the efficiency of searching for a crystal structure can be improved.

[0009] Further advantages and effects in an aspect of the present disclosure will be clarified from the specification and the drawings. Such advantages and / or effects are provided by some embodiments and the features described in the specification and the drawings respectively, but not all of them are necessarily provided in order to obtain one or more identical features.

Brief Description of the Drawings

[0010] [Figure 1] FIG. 1 is a diagram showing an example of the external configuration of an information processing system in an embodiment. [Figure 2] FIG. 2 is a block diagram showing an example of the functional configuration of an information processing apparatus in an embodiment. [Figure 3] FIG. 3 is a diagram schematically showing a specific example of processing performed by an information processing apparatus in an embodiment. [Figure 4] FIG. 4 is a diagram showing Wyckoff positions. [Figure 5] FIG. 5 is a diagram for explaining the processing of the information processing apparatus until the first crystal structure is generated in the embodiment. [Figure 6] FIG. 6 is a diagram for explaining the processing of the information processing apparatus until the second crystal structure is generated from the first crystal structure in the embodiment. [Figure 7] FIG. 7 is a diagram for explaining the output of the information processing apparatus in the embodiment. [Figure 8] FIG. 8 is a flowchart showing an example of the processing operation of the information processing apparatus in the embodiment. [Figure 9] FIG. 9 is a flowchart showing an example of the processing operation of the first generation unit in the embodiment. [Figure 10] FIG. 10 is a flowchart showing an example of the processing operation of the second generation unit in the embodiment. [Figure 11] FIG. 11 is a diagram for explaining the symmetry of 230 space groups. [Figure 12] FIG. 12 is a diagram showing another example of the input reception screen in the embodiment.

Embodiments for Carrying Out the Invention

[0011] (Findings Leading to the Present Disclosure) The present inventor has found that the following problems occur with respect to the material creation method of Patent Document 1 described in the "Background Art" section.

[0012] In the material creation method described in Patent Document 1, as mentioned above, atomic positions are determined randomly. As a result, in the crystal structure generated by this material creation method, multiple atoms may be in close proximity. Furthermore, the more atoms contained in the crystal structure, the higher the probability that those atoms will be in close proximity. Here, if multiple atoms contained in the crystal structure are too close together, the energy of that crystal structure tends to diverge, making it difficult to properly evaluate the energy of that crystal structure. In other words, even if a crystal structure is generated, it is not possible to perform an energy evaluation to obtain the physical properties of that crystal structure, and the crystal structure is rejected. Therefore, the material creation method described in Patent Document 1 has the problem that the efficiency of generating crystal structures whose physical properties can be evaluated is low, and it is difficult to efficiently search for crystal structures.

[0013] Therefore, the information processing method according to the first aspect of the present disclosure is an information processing method performed by an information processing device, which acquires elemental information relating to two or more elements, generates a first element set containing one or more elements and a second element set containing one or more elements by classifying the two or more elements based on predetermined conditions, generates a second crystal structure by arranging the one or more elements contained in the second element set in a first crystal structure composed of the one or more elements contained in the first element set, and outputs output information relating to the second crystal structure.

[0014] As a result, when a second crystal structure containing two or more elements is formed, the remaining one or more elements from that second or more element are arranged in the first crystal structure, which is composed of one or more elements from that second or more element. In other words, the second crystal structure is formed by using the first crystal structure as a framework. Therefore, the possibility of the two or more elements in the second crystal structure being too close together can be suppressed. As a result, an energetically stable second crystal structure, i.e., a second crystal structure whose physical properties can be evaluated, can be efficiently generated. Therefore, crystal structures can be efficiently explored.

[0015] Furthermore, in the information processing method according to the second embodiment, the second crystal structure may be an inorganic crystal structure or an ionic crystal structure. The second embodiment may be dependent on the first embodiment.

[0016] This allows for the efficient exploration of inorganic or ionic crystal structures.

[0017] Furthermore, in the information processing method according to the third embodiment, the second crystal structure may be a low-symmetry structure. The third embodiment may be dependent on the first or second embodiment.

[0018] This allows for the efficient search for low-symmetry second crystal structures, even if the second crystal structure is low-symmetry.

[0019] Furthermore, in the information processing method relating to the fourth embodiment, the predetermined conditions may include the condition of separating the two or more elements into anions and cations. Note that the fourth embodiment may be dependent on any one of the first to third embodiments.

[0020] This allows for the generation of, for example, a first element set containing anions and a second element set containing cations.

[0021] Furthermore, in the information processing method according to the fifth embodiment, the one or more elements included in the first element set are anions, and in the generation of the second crystal structure, a highly symmetric structure composed of the anions may be generated as the first crystal structure. Note that the fifth embodiment may be dependent on the fourth embodiment.

[0022] This generates a highly symmetrical first crystal structure, which effectively suppresses the proximity of multiple elements within that first crystal structure. As a result, even if a second crystal structure is formed by the placement of one or more elements from the second element set into this first crystal structure, the proximity of two or more elements within that second crystal structure can be suppressed. Therefore, the search for crystal structures can be made more efficient.

[0023] Furthermore, in the information processing method according to the sixth embodiment, the second crystal structure may be generated by arranging one or more elements included in the second element set into a plurality of vacancies included in the first crystal structure. Note that the sixth embodiment may be dependent on any one of the first to fifth embodiments.

[0024] This reduces the proximity of two or more elements in the second crystal structure, making the search for the crystal structure more efficient.

[0025] Furthermore, in the information processing method according to the seventh embodiment, in the generation of the second crystal structure, an optimization process may be performed on the arrangement of the one or more elements included in the second element set. The seventh embodiment may be dependent on the sixth embodiment.

[0026] This optimizes the arrangement of one or more elements in the second element set for multiple vacancies in the first crystal structure, thereby generating an energetically stable second crystal structure. As a result, the search for crystal structures can be made more efficient.

[0027] Furthermore, in the information processing method according to the eighth embodiment, the first crystal structure may be generated by further arranging one or more elements included in the first element set according to the first space group. Note that the eighth embodiment may be dependent on any one of the first to seventh embodiments.

[0028] This allows, for example, one space group to be selected from 230 space groups as the first space group, and a first crystal structure to be generated according to that first space group. As a result, the first crystal structure can be generated appropriately, and furthermore, the second crystal structure can also be generated appropriately.

[0029] Also, in the information processing method according to the ninth aspect, in the generation of the second crystal structure, one or more second space groups that are candidates for the first space group are restricted from N (N is an integer of 2 or more) second space groups to M (M is an integer satisfying 1 < M < N) second space groups, and one of the M second space groups included in the M second space groups may be used as the first space group. Note that the ninth aspect may depend on any one of the first to eighth aspects. For example, the one or more second space groups are the above-described 230 space groups.

[0030] Thereby, the first space group can be restricted to, for example, a highly symmetric space group. As a result, the proximity of two or more types of elements included in the second crystal structure can be suppressed, and the search for the crystal structure can be made more efficient.

[0031] Also, the information processing system according to the first aspect includes an acquisition unit that acquires element information regarding two or more types of elements, a classification unit that generates a first element set including one or more types of elements and a second element set including one or more types of elements by classifying the two or more types of elements based on a predetermined condition, a generation unit that generates a second crystal structure by arranging the one or more types of elements included in the second element set in a first crystal structure constituted by using the one or more types of elements included in the first element set, and an output unit that outputs output information regarding the second crystal structure.

[0032] Thereby, the same operational effects as those of the information processing method according to the first aspect can be achieved.

[0033] Also, the information processing system according to the second aspect includes an acquisition unit that acquires element information regarding two or more types of elements, and an output unit that outputs and displays first image information and second image information on a display unit. The first image information shows a first crystal structure constituted by using one or more types of elements included in a first element set among the two or more types of elements, and the second image information shows a second crystal structure constituted by arranging one or more types of elements included in a second element set among the two or more types of elements in the first crystal structure.

[0034] As a result, the first and second crystal structures are displayed on the display unit, allowing the user to see not only the second crystal structure but also the first crystal structure used to create it. This, in turn, can assist the user in exploring crystal structures.

[0035] The embodiments of this disclosure will be described below with reference to the drawings. The embodiments described below are all preferred specific examples of this disclosure. Therefore, the numerical values, shapes, materials, components, arrangement positions of components, and connection configurations shown in the following embodiments are examples and are not intended to limit this disclosure. Accordingly, among the components in the following embodiments, those components that are not described in the independent claim representing the highest-level concept will be described as optional components.

[0036] Note that each figure is a schematic diagram and not necessarily a strictly accurate representation. Furthermore, the same reference numerals are used for substantially identical components in each figure, and redundant explanations are omitted or simplified. The effects and benefits of the above information processing method are similarly realized in information processing devices, information processing systems, and programs.

[0037] (Embodiment) Figure 1 shows an example of the external configuration of the information processing system in this embodiment.

[0038] The information processing system 1 in this embodiment comprises an information processing device 100, an input unit 200, and a display unit 300. The information processing device 100 is a computer comprising, for example, a processor such as a CPU (Central Processing Unit) and a recording medium such as memory. The input unit 200 accepts, for example, input operations from a user and outputs a signal corresponding to that input operation to the information processing device 100. Specifically, the input unit 200 is a keyboard or a mouse, but is not limited to these and may be any hardware. The display unit 300 is a device that displays an image or screen corresponding to the signal output from the information processing device 100. Such a display unit 300 is, for example, a liquid crystal display, a plasma display, or an organic EL (Electro-Luminescence) display, but is not limited to these. Furthermore, the information processing system 1 may be configured as a tablet terminal. In this case, the information processing device 100, the input unit 200, and the display unit 300 are configured as a single unit. In this case, the input unit 200 is configured as a touch sensor that accepts input operations corresponding to an image, such as an icon, when the user touches the image displayed on the display unit 300.

[0039] Figure 2 is a block diagram showing an example of the functional configuration of the information processing device 100 in this embodiment.

[0040] The information processing device 100 comprises an acquisition unit 101, a classification unit 102, a first generation unit 103, a second generation unit 104, and an output unit 105. These components may be realized by the aforementioned processor executing a program stored in memory.

[0041] The acquisition unit 101 acquires elemental information da from the input unit 200 in response to an input operation by the user to the input unit 200. The elemental information da is information about two or more elements. The acquisition unit 101 may also acquire elemental information da from outside the information processing system 1 by communicating wirelessly or via wired connection. Wireless communication may be performed using Wi-Fi®, Bluetooth®, ZigBee®, or low-power radio.

[0042] The classification unit 102 generates a first element set containing one or more elements and a second element set containing one or more elements by classifying two or more elements indicated by elemental information da based on predetermined conditions. In other words, the classification unit 102 divides two or more elements into a first element set and a second element set.

[0043] The first generation unit 103 generates a first crystal structure. The first crystal structure is a crystal structure composed of one or more elements included in the first element set.

[0044] The second production unit 104 generates a second crystal structure. In other words, the second production unit 104 generates the second crystal structure by arranging one or more elements included in the second element assembly into the first crystal structure generated by the first production unit 103.

[0045] The output unit 105 outputs input acceptance information db to the display unit 300 to prompt the user to input the elemental information da described above. The display unit 300 then prompts the user to input the elemental information da by displaying a screen corresponding to the input acceptance information db. Furthermore, when the first crystal structure and the second crystal structure are generated by the first generation unit 103 and the second generation unit 104, the output unit 105 outputs information about the generated first crystal structure and second crystal structure as output information dc. Output information dc, for example, shows the first crystal structure and the second crystal structure, respectively.

[0046] FIG. 3 is a diagram schematically showing a specific example of processing performed by the information processing apparatus 100 according to the present embodiment.

[0047] The acquisition unit 101 of the information processing apparatus 100 acquires elemental information da. The elemental information da indicates, for example, a composition formula as two or more types of elements. As a more specific example, the elemental information da is the composition formula "Fe

[0049] , 12 , 16 , , 12 , , 16 , , 16 , ,

[0050] , 12 O 16 ". The classification unit 102 divides the composition formula "Fe 12 O 16 " into a first element set containing 16 O atoms (i.e., "O 16 ") and a second element set containing 12 Fe atoms (i.e., "Fe 12 ") according to a predetermined condition.

[0048] The predetermined condition is, for example, a condition that among two or more types of elements indicated by the elemental information da, one or more types of predetermined elements are included in the first element set, and the remaining one or more types of elements are included in the second element set. The one or more types of predetermined elements are, for example, at least one element among [S, O, N, F, Cl, Br, I]. Alternatively, the predetermined condition may be a condition that divides the composition formula into a cation and an anion. As a result, the first element set "O 16 " and the second element set "Fe 12 " are generated.

[0049] The first generation unit 103 generates a first crystal structure as the crystal structure of the first element set "O 16 ". The first crystal structure contains 16 O atoms. The second generation unit 104 arranges the 12 Fe atoms included in the second element set "Fe 12 " in the first crystal structure to generate a second crystal structure as the crystal structure of the composition formula "Fe 12 O 16 ". The second crystal structure contains 16 O atoms and 12 Fe atoms.

[0050] Thus, in this embodiment, when a second crystal structure having two or more elements is generated, the remaining one or more elements are arranged in a first crystal structure composed of one or more elements included in those two or more elements. In other words, the second crystal structure is generated by using the first crystal structure as a framework. Therefore, the possibility of the two or more elements included in the second crystal structure being too close together can be suppressed. As a result, an energetically stable second crystal structure, i.e., a second crystal structure whose physical properties can be evaluated, can be efficiently generated. That is, the user can efficiently search for crystal structures.

[0051] Furthermore, the second crystal structure generated in this embodiment is, for example, an inorganic crystal structure or an ionic crystal structure. Therefore, inorganic crystal structures or ionic crystal structures can be efficiently searched for. Moreover, the second crystal structure may be a low-symmetry structure. In other words, in this embodiment, even if the crystal structure of the target material is low-symmetry, a second crystal structure that is assumed to be the low-symmetry crystal structure of the target material can be efficiently generated and searched for. To put it another way, even if the target crystal structure is a low-symmetry crystal structure, the proportion of generated invalid (i.e., unappraisable) crystal structures can be reduced, and crystal structures can be efficiently generated.

[0052] Furthermore, the predetermined conditions used by the classification unit 102 in this embodiment include the condition of separating two or more elements indicated by elemental information da into anions and cations. In the above example, the two or more elements are the first element set "O" which corresponds to anions. 16 " and the second element set corresponding to a cation, "Fe 12This can be divided into two parts: a first element set containing anions and a second element set containing cations. In addition, one or more elements in the first element set are anions. The first generation unit 103 may also generate a highly symmetric structure composed of anions as the first crystal structure. As a result, a highly symmetric first crystal structure is generated, which sufficiently suppresses the proximity of multiple elements contained in the first crystal structure. Consequently, even if a second crystal structure is generated by arranging one or more elements from the second element set in such a first crystal structure, the proximity of two or more elements contained in that second crystal structure can be suppressed. Therefore, the search for crystal structures can be made more efficient.

[0053] In this embodiment, when generating the first crystal structure, the first generation unit 103 randomly selects one space group from, for example, 230 space groups. In a specific example, the first generation unit 103 selects one space group identified by the value "221" from 230 space groups identified by integer values ​​from "1" to "230". Then, the first generation unit 103 generates the first crystal structure according to the selected space group.

[0054] Figure 4 shows the Wyckoff position of the space group "221". Note that the space group "221" is a space group identified by the value "221".

[0055] The first generation unit 103 selects a space group such as "221" and generates a first crystal structure using the Wyckoff positions of that space group. As shown in Figure 4, the space group "221" has 14 Wyckoff positions. Each of the 14 Wyckoff positions is represented by a multiplicity and a Wyckoff letter, as shown in Figure 4. For example, the first generation unit 103 randomly selects one Wyckoff position from these 14 Wyckoff positions and generates a first crystal structure according to the selected Wyckoff position. In the following example, one Wyckoff position is selected for the generation of the first crystal structure, but the number of Wyckoff positions selected may be two or more.

[0056] Figure 5 is a diagram illustrating the processing of the information processing device 100 until the first crystal structure is generated.

[0057] First, the output unit 105 outputs the input reception information db to the display unit 300. The display unit 300 displays the input reception screen 310 according to the input reception information db. The input reception screen 310 includes a composition formula input field 211, a first element set field 212, a second element set field 213, and an execution button 214. In the initial input reception screen 310, the composition formula input field 211, the first element set field 212, and the second element set field 213 are all blank.

[0058] Next, the acquisition unit 101 acquires elemental information da in response to input operations on the input unit 200 by the user who has viewed the input reception screen 310, and outputs the compositional formula shown in that elemental information da to the classification unit 102 and the output unit 105. As a result, the output unit 105 displays the compositional formula in the compositional formula input field 211 of the input reception screen 310. For example, if the compositional formula is "Fe 12 O 16 " is displayed in the composition formula input field 211.

[0059] Next, the classification unit 102 processes the composition formula "Fe" shown in the elemental information da. 12 O 16 From ", the first element set "O 16 " and the second element set "Fe 12 The classification unit 102 then generates the first element set "O 16 " and the second element set "Fe 12 Information indicating "O" is output to the first generation unit 103 and the output unit 105. As a result, the output unit 105 outputs the information that indicates "O" as the first element set. 16 The first element set field 212 of the input reception screen 310 displays "Fe". Furthermore, the output unit 105 displays "Fe", which is shown as the second element set in that information. 12 This is displayed in the second element set field 213 of the input reception screen 310.

[0060] Next, in response to the user's input operation to the input unit 200, the first generation unit 103, when the execution button 214 displayed as "run" is selected, generates the first element set "O 16 For example, the space group "221" is selected as the space group. Furthermore, the first generator 103 selects one Wyckoff position from among the multiple Wyckoff positions associated with the space group "221", i.e., the multiple Wyckoff positions shown in Figure 4. For example, the first generator 103 randomly selects one Wyckoff position. Here, Wyckoff position "1a" is selected as a specific example. Note that this Wyckoff position "1a" includes a multiplicity of "1" and a Wyckoff letter "a".

[0061] Next, the first generating unit 103 decides whether or not to re-select the Wyckoff position based on the selected Wyckoff position and the first element set. In a specific example, when the multiplicity of the selected Wyckoff position is expressed as variable m and the number of atoms included in the first element set is expressed as variable n, the first generating unit 103 determines whether m > n is satisfied and whether variable n is divisible by variable m. If the first generating unit 103 determines that m > n is satisfied, or that variable n is not divisible by variable m, it decides to re-select the Wyckoff position. In this case, the first generating unit 103 randomly selects one Wyckoff position from the remaining one or more Wyckoff positions excluding the already selected Wyckoff position. On the other hand, if the first generating unit 103 determines that m > n is not satisfied and that variable n is divisible by variable m, it decides not to re-select the Wyckoff position.

[0062] For example, the first element set "O 16If " " is generated and "1a" is selected as the Wyckoff position, then the variables n and m are n=16 and m=1. In this case, the first generation unit 103 determines that m>n is not satisfied and that variable n is a number divisible by variable m. Therefore, the first generation unit 103 decides not to re-select the Wyckoff position. In other words, the first generation unit 103 determines the most recently selected Wyckoff position as the final Wyckoff position.

[0063] Next, the first generation unit 103 generates a structure defined by the finally determined Wyckoff position. The first generation unit 103 then expands this structure into a supercell by linking L (L=n / m) of these structures. This supercell is the first crystal structure. For example, if the finally determined Wyckoff position is "1a", the first generation unit 103 generates a structure defined by that Wyckoff position "1a". Note that the number of atoms in the crystal lattice of this structure is one. The first generation unit 103 then links four of these structures in the X-axis direction, two of these structures in the Y-axis direction, and two more of these structures in the Z-axis direction. This links 16 structures (i.e., L=4×2×2). The entirety of these 16 linked structures corresponds to a supercell (i.e., the first crystal structure), which in the above example is denoted as supercell[4,2,2].

[0064] Thus, in this embodiment, the first generation unit 103 generates a first crystal structure by arranging one or more elements included in the first element set according to a first space group. This first space group is, for example, a space group selected from 230 space groups as described above. This makes it possible to select one space group from 230 space groups as the first space group and generate a first crystal structure according to that first space group. As a result, a first crystal structure can be appropriately generated, and furthermore, a second crystal structure can also be appropriately generated.

[0065] The first crystal structure may be generated based on existing known methods (e.g., PyXtal). Furthermore, if the first element set contains multiple types of elements, the first generation unit 103 first generates the crystal structure by treating all elements in the first element set as the same type. Then, the first generation unit 103 may generate the first crystal structure by assigning one of each of the multiple types of elements to each atomic arrangement (also called atomic coordinate) of the crystal structure.

[0066] Furthermore, in the example described above, the first generator 103 selects the space group "221," but other space groups may also be selected. For example, the space group "1," which has no symmetries other than translational symmetry, may be selected. Note that space group "1" is the space group identified by the value "1" among the 230 space groups. In this case, the first generator 103 generates the first crystal structure of space group "1" by determining six lattice parameters and the atomic arrangement of 16 O atoms using random numbers. If a specific space group other than space group "1" is selected, the first generator 103 generates the first crystal structure by determining the atomic arrangement using random numbers, taking into account the multiplicity included in the Wyckoff positions of that space group.

[0067] Specifically, the first generating unit 103 generates a first crystal structure having, for example, four symmetric sites (i.e., atomic arrangements) of all atoms, according to the multiplicity of its particular space group. In this case, once one of the four atomic arrangements is determined, the symmetry of the four sites automatically determines the remaining three atomic arrangements. Therefore, the first generating unit 103 determines the four atomic arrangements by determining one atomic arrangement using a random number, and then generates a first element set (e.g., O 16 A first crystal structure of ) is generated. In this embodiment, the crystal structure, such as the first crystal structure, is a structure determined using lattice parameters and atomic arrangement (i.e., atomic coordinates).

[0068] In another, more specific example, the first generation unit 103 generates a first crystal structure in which 48 atoms are symmetrically arranged according to the multiplicity "48" of the Wyckoff position "48n" of the space group "221". In this case, once one of the 48 atomic arrangements is determined, the symmetry of the 48 atoms automatically determines the arrangements of the remaining 47 atoms. Therefore, the first generation unit 103 determines the 48 atomic arrangements by determining one atomic arrangement using random numbers, and generates a first crystal structure containing those 48 atoms. On the other hand, if the multiplicity of the Wyckoff position is not used, it is necessary to determine each of the 48 atomic arrangements (i.e., the X, Y, and Z coordinates) individually, for example, using random numbers. However, in this embodiment, the first crystal structure can be efficiently generated by using multiplicity. Furthermore, the probability of any two atoms being in close proximity is lower for the first crystal structure generated using multiplicity than for the crystal structure generated without using multiplicity. Therefore, in this embodiment, the first crystal structure can be efficiently generated in this respect as well. Furthermore, while the probability of any two atoms being in close proximity increases with the number of atoms in the crystal structure, this embodiment effectively suppresses that probability even with a large number of atoms.

[0069] Figure 6 is a diagram illustrating the processing of the information processing device 100 from the first crystal structure to the generation of the second crystal structure.

[0070] When the second generation unit 104 obtains the first crystal structure from the first generation unit 103, it detects one or more vacancies in the first crystal structure (i.e., the supercell), as shown in Figure 6(a). For example, the second generation unit 104 obtains the second element set from the classification unit 102 via the first generation unit 103, calculates the energy change when the elements included in the second element set are placed at arbitrary locations in the first crystal structure, and obtains an energy surface. Then, the second generation unit 104 detects the coordinates that are local solutions on that energy surface as vacancies. For example, the first element set "O 16If the first crystal structure of " is a supercell [4,2,2] as described above, the second generation unit 104 detects 16 vacancies. Then, the second generation unit 104 generates the second elemental aggregate "Fe 12 Each of the 12 Fe atoms contained in the sample is assigned to one of the 16 detected vacancies without any overlap.

[0071] As a result, as shown in Figure 6(b), 12 Fe atoms are placed in 12 of the 16 vacancies in the first crystal structure. This arrangement of 12 Fe atoms generates the second crystal structure. The second crystal structure thus generated may belong to the space group identified by the value "25" (i.e., space group "25") out of 230 space groups. In other words, the second crystal structure may be a low-symmetry crystal structure.

[0072] Here, the second generation unit 104 may further relax the structure of the generated second crystal structure, as shown in Figure 6(c). That is, the second generation unit 104 adjusts the lattice parameters and atomic arrangement of the second crystal structure shown in Figure 6(b) by performing energy optimization, including lattice parameters and atomic arrangement. As a result, for example, a second crystal structure belonging to the space group identified by the value "1" (i.e., space group "1") out of 230 space groups may be generated. In other words, the second crystal structure may be an even less symmetric crystal structure.

[0073] Thus, in this embodiment, the second generation unit 104 generates a second crystal structure by arranging one or more elements included in the second element aggregate in each of the multiple vacancies included in the first crystal structure. This suppresses the proximity of two or more elements included in the second crystal structure, making the search for the crystal structure more efficient.

[0074] Figure 7 is a diagram illustrating the output of the information processing device 100 in this embodiment.

[0075] When the output unit 105 obtains the first crystal structure from the first production unit 103 and the second crystal structure from the second production unit 104, it outputs output information dc showing the first and second crystal structures to the display unit 300. The output information dc may further show the composition formula, the first element set, and the second element set. When the display unit 300 obtains the output information dc, it displays an output screen 320 corresponding to the output information dc, for example, as shown in Figure 7.

[0076] The output screen 320 includes, as images or text, each of the compositional formula, first element set, second element set, first crystal structure, and second crystal structure shown in the output information dc. The compositional formula is the compositional formula shown in the elemental information da, for example, "Fe 12 O 16 The first element set and the second element set are two sets generated by the classification unit 102, for example, "O 16 " and "Fe 12 The first crystal structure is a crystal structure produced by the first production unit 103 based on the first element set, and is, for example, a crystal structure containing 16 O atoms defined by the space group "221" described above. The second crystal structure is a crystal structure produced by the second production unit 104 based on the first crystal structure and the second element set. For example, the second crystal structure is a crystal structure containing 16 O atoms and 12 Fe atoms defined by the space group "25" described above.

[0077] As described above, the information processing device 100 in this embodiment, that is, the information processing system 1 including the information processing device 100, comprises an acquisition unit 101 that acquires elemental information da, and an output unit 105 that outputs and displays first image information and second image information to a display unit 300. The first image information shows a first crystal structure composed of one or more elements included in the first element set from among the two or more elements indicated by the elemental information da. The second image information shows a second crystal structure composed of one or more elements included in the second element set from among the two or more elements arranged in the first crystal structure.

[0078] As a result, the first and second crystal structures are displayed on the display unit 300, allowing the user to see not only the second crystal structure but also the first crystal structure used to create it. This supports the user's search for crystal structures.

[0079] Figure 8 is a flowchart showing an example of the processing operation of the information processing device 100 in this embodiment.

[0080] The acquisition unit 101 of the information processing device 100 acquires elemental information da from the input unit 200 (step S10). Then, the classification unit 102 generates a first element set and a second element set by classifying the element set, such as the composition formula, indicated by the elemental information da (step S20).

[0081] Next, the first generation unit 103 generates the crystal structure of the generated first element set as the first crystal structure (step S30). Then, the second generation unit 104 generates the second crystal structure as the crystal structure of the element set shown in element information da, based on the generated first crystal structure and the second element set generated in step S20 (step S40).

[0082] Subsequently, the output unit 105 outputs output information dc indicating the first crystal structure generated in step S30 and the second crystal structure generated in step S40 to the display unit 300, thereby displaying the first and second crystal structures on the display unit 300 (step S50).

[0083] Here, in step S30 of Figure 8, the first generation unit 103 selects, for example, one space group randomly from the entire range including 230 space groups, and generates a first crystal structure based on the selected space group. However, the first generation unit 103 may also generate the first crystal structure as shown in the example in Figure 9.

[0084] FIG. 9 is a flowchart showing an example of the processing operation of the first generation unit 103. It can also be said that this flowchart shows the processing of step S30 in FIG. 8 in detail.

[0085] First, the first generation unit 103 selects, as the first space group, a space group used for generating the first crystal structure from, for example, 230 space groups (hereinafter also referred to as the second space groups) (step S31). At this time, the first generation unit 103 restricts the range in which the first space group is selected from the entire range including the 230 second space groups. Then, the first generation unit 103 selects one second space group as the first space group from a plurality of second space groups included in the restricted range. After that, the first generation unit 103 generates a first crystal structure corresponding to the selected space group (that is, the first space group) (step S32).

[0086] That is, the first generation unit 103 restricts one or more second space groups each serving as a candidate for the first space group from N (N is an integer of 2 or more) second space groups to M (M is an integer satisfying 1 < M < N) second space groups. Then, the first generation unit 103 uses one second space group included in the M second space groups as the first space group. For example, each of the restricted M second space groups is a high-symmetry space group. As a result, the first space group can be restricted to a high-symmetry space group. Consequently, a high-symmetry first crystal structure can be generated, and furthermore, the proximity of two or more types of elements included in the second crystal structure generated from the first crystal structure can be suppressed. Therefore, the search for the crystal structure can be made more efficient.

[0087] For example, to improve diversity, one could use each of the 230 space groups as the first space group to generate the first and second crystal structures. However, in this case, the cost required would be 230 times greater than the cost of generating a single second crystal structure. In other words, the search for crystal structures would be inefficient. If the crystal structure of the target material is low-symmetry, the space groups can be restricted to low-symmetry space groups, but this does not significantly reduce the number of atomic arrangements generated randomly, making it inefficient. On the other hand, even if the crystal structure of the actual target material is low-symmetry, some elements (i.e., one or more elements) contained in that crystal structure often have a high-symmetry structure. Therefore, in the example in Figure 9, the information processing device 100 generates a high-symmetry first crystal structure by restricting the selected space groups. That is, the information processing device 100 generates a first crystal structure corresponding to a part of the crystal structure of the target material by arranging one or more elements contained in the first element set with high symmetry. Then, the information processing device 100 arranges the remaining one or more elements contained in the second crystal structure in that first crystal structure. This allows for the efficient generation of a second crystal structure, which is assumed to be the crystal structure of the target material, even if the target material's crystal structure is low-symmetry. Furthermore, by efficiently generating the second crystal structure, the cost of generating the second crystal structure in the information processing device 100 can be reduced. In this embodiment, for example, the generation of the first crystal structure using PyXtal as described above may be executed as processing by a processor that has loaded a program. The image signals (i.e., output information dc) showing the first and second crystal structures are output to the display unit 300, and as shown in Figure 7, the crystal structures are displayed side by side in a way that allows for comparison. The image signals may be stored in memory and may be transmitted to external devices via wireless or wired connections, or via a communication network such as the Internet.

[0088] In the example above, one first space group is selected, but it is also possible to select M second space groups, each as a first space group. In this case, M first crystal structures are generated, and furthermore, M second crystal structures are generated. That is, all M highly symmetric first crystal structures are generated, and M second crystal structures may be generated from these highly symmetric first crystal structures.

[0089] Here, in step S40 of Figure 8, the second production unit 104 generates the second crystal structure by, for example, randomly arranging one or more elements included in the second element set into multiple vacancies in the first crystal structure. In other words, the second production unit 104 uses random numbers to assign one or more elements included in the second element set to multiple vacancies. Alternatively, the second production unit 104 assigns elements to the vacancies in order from those closest to predetermined positions among the multiple vacancies. However, the second production unit 104 may also generate the second crystal structure by assigning one or more elements to multiple vacancies, as in the example shown in Figure 10.

[0090] Figure 10 is a flowchart illustrating an example of the processing operation of the second generation unit 104. This flowchart can also be seen as a detailed representation of the processing in step S40 of Figure 8.

[0091] The second generation unit 104 detects one or more vacancies in the first crystal structure generated by the first generation unit 103 (step S41). Next, the second generation unit 104 optimizes how to assign one or more elements included in the second element set to the one or more vacancies detected in step S41 (step S42). For example, if 16 vacancies are detected in step S41 and the second element set contains 12 atoms, the second generation unit 104 optimizes how to assign the 12 atoms of one or more elements to the 16 vacancies. In other words, the second generation unit 104 determines the assignment in such a way that it optimizes predetermined evaluation criteria based on that assignment. The predetermined evaluation criteria may be, for example, minimizing energy based on first-principles calculations, minimizing energy prediction values ​​by machine learning, or minimizing values ​​obtained by an evaluation function based on the relative positional relationship of atoms. For example, the evaluation function is a function that shows a larger value the more often atoms are placed in adjacent vacancies. Note that the optimization algorithm is not limited to these and may be any algorithm. Alternatively, the second generating unit 104 may determine the above-mentioned assignment method as a maximum matching problem of a bipartite graph based on the energy change when one atom is placed.

[0092] Thus, in this embodiment, the second generation unit 104 may perform optimization processing on the arrangement of one or more elements included in the second element set. This optimizes the arrangement of one or more elements included in the second element set for multiple vacancies in the first crystal structure, and as a result, an energetically stable second crystal structure can be generated. Consequently, the search for crystal structures can be made more efficient. Furthermore, in this embodiment, optimization processing such as minimizing energy based on first-principles calculations, minimizing energy prediction values ​​by machine learning, or minimizing values ​​obtained by evaluation functions based on the relative positional relationships of atoms may be performed as processing by a processor that has loaded the program.

[0093] Figure 11 is a diagram illustrating the symmetries of 230 space groups.

[0094] A space group is said to be highly symmetric if it allows for many symmetry operations, such as rotation and reflection. In Figure 11, each of the 230 space groups is represented by a mark with a shape corresponding to its crystal system (e.g., triclinic). Furthermore, space groups that allow for many symmetry operations are positioned lower in Figure 11. Here, one of two space groups possesses all the symmetry operations that the other space group possesses, plus one additional symmetry operation. In this case, in Figure 11, one space group is positioned lower than the other space group. Thus, one space group can be said to belong to the supergroup of the other space group. Conversely, the other space group can be said to belong to the subgroup of the other space group.

[0095] In this embodiment, a highly symmetric space group is, for example, a space group included in these 230 space groups, and is a space group for which no other space groups belong to its supergroup. In other words, the highly symmetric space group shown in Figure 11 is the space group located at the lower end. As a specific example, the highly symmetric space group comprises 43 out of 230 space groups and is identified by the numerical values ​​"51, 52, 53, 54, 57, 60, 62, 64, 91, 95, 124, 125, 127, 128, 129, 130, 132, 133, 135, 136, 137, 138, 178, 179, 180, 181, 191, 192, 193, 194, 205, 212, 213, 221, 222, 223, 224, 225, 226, 227, 228, 229, 230". Note that these highly symmetric space groups may also be space groups calculated based on t-subgroups by referring to PyXtal. On the other hand, the less symmetric space groups are the space groups from the 230 space groups excluding the highly symmetric space groups.

[0096] Alternatively, the highly symmetric space group in this embodiment may be a space group in which the degrees of freedom for atomic arrangement and lattice parameters are less than or equal to a predetermined ratio. The predetermined ratio is the ratio of the degrees of freedom for atomic arrangement and lattice parameters in other space groups to the degrees of freedom for atomic arrangement and lattice parameters in space group "1", for example, 25%. If the ratio of the degrees of freedom for atomic arrangement and lattice parameters in other space groups is less than or equal to the predetermined ratio, then the other space group is a highly symmetric space group. For example, in a space group in which all atoms are arranged in four symmetric sites, once the coordinates (X, Y, and Z coordinates) of one site are determined, the coordinates of the other three sites are also determined. On the other hand, in space group "1", there is no symmetry between the four sites, so it is necessary to determine the coordinates of each of the four sites. In this case, the ratio of degrees of freedom for the space group in which all atoms are arranged in four symmetric sites is 25%, and that space group is a highly symmetric space group.

[0097] Figure 12 shows another example of the input reception screen in this embodiment.

[0098] The output unit 105 may output the input reception information db to the display unit 300, thereby displaying the input reception screen 311 shown in Figure 12 instead of the input reception screen 310 shown in Figure 5. The input reception screen 311 does not include the composition formula input field 211, but includes the first element set field 212, the second element set field 213, and the execute button 214. In the initial input reception screen 311, the first element set field 212 and the second element set field 213 are both blank.

[0099] The acquisition unit 101, in response to the user's input operation to the input unit 200 after viewing the input reception screen 311, directly acquires the first element set and the second element set without acquiring element information da, and outputs them to the first generation unit 103 and the output unit 105. In other words, in the example in Figure 12, the user inputs the first element set and the second element set, rather than the compositional formula, through the input operation to the input unit 200. Therefore, in the example in Figure 12, the user can arbitrarily determine the first element set and the second element set.

[0100] The output unit 105 displays the first element set and the second element set in the first element set field 212 and the second element set field 213 of the input reception screen 311, respectively. For example, the first element set is "O 16 " is displayed in the first element set field 212, and "Fe" is displayed as the second element set. 12 " is displayed in the second element set field 213. In this example of Figure 12, the information processing device 100 does not need to include the classification unit 102.

[0101] As described above, the information processing system 1, the information processing device 100, and the information processing method performed by them in this embodiment can improve the efficiency of crystal structure exploration. This makes it possible to advance, improve the efficiency and speed of material development. In other words, the evaluation device can efficiently and quickly obtain the physical properties of a material having the composition formula indicated by elemental information da, based on the second crystal structure indicated by the output information dc output from the information processing device 100. Therefore, the material production device can efficiently and quickly produce a material having the desired physical properties.

[0102] <Other forms> Although the information processing system, information processing apparatus, and information processing method relating to this disclosure have been described based on the embodiments described above, this disclosure is not limited to the embodiments described above. Various modifications to the embodiments that a person skilled in the art could conceive of are also included within the scope of this disclosure, as long as they do not deviate from the spirit of this disclosure.

[0103] For example, the predetermined conditions used by the classification unit 102 in the above embodiment may be conditions based on ionic radius, or conditions based on the periodic table or atomic number. Specifically, the predetermined conditions may include elements whose ionic radius is greater than or equal to a threshold in the first element set, and elements whose ionic radius is less than a threshold in the second element set. The threshold is, for example, 1.3 Å. Alternatively, the predetermined conditions may be conditions based on at least one of the groups of the periodic table, periods of the periodic table, and atomic number. For example, the conditions may include including one or more elements belonging to the first to third periods of the periodic table in the first element set, and including the remaining one or more elements in the second element set, from among two or more elements indicated by element information da.

[0104] Furthermore, although the output unit 105 in the above embodiment outputs output information dc showing the first crystal structure and the second crystal structure, it may also output output information dc showing only the second crystal structure among those crystal structures. In this case, the display unit 300 will not display the first crystal structure, but will display the second crystal structure.

[0105] Furthermore, each component included in the information processing system 1 in the above embodiment may be connected to one another via a communication network such as the Internet.

[0106] Furthermore, the process of generating the first crystal structure and the second crystal structure in the above embodiment can also be described as a process of determining the first crystal structure and the second crystal structure, or a process of generating information indicating the first crystal structure and information indicating the second crystal structure. Similarly, the process of generating the first element set and the second element set can also be described as a process of determining the first element set and the second element set, or a process of generating information indicating the first element set and information indicating the second element set.

[0107] Furthermore, in the above embodiments, each component may be implemented by dedicated hardware or by executing a software program suitable for each component. Each component may also be implemented by a program execution unit such as a CPU or processor reading and executing a software program recorded on a recording medium such as a hard disk or semiconductor memory. Here, the program that implements the information processing device, etc., of each embodiment may, for example, cause the processor to execute each step included in at least one flowchart in Figures 8, 9, and 10.

[0108] The following cases are also included in this disclosure.

[0109] (1) The above-mentioned at least one device or system is specifically a computer system consisting of a microprocessor, ROM (Read Only Memory), 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 above-mentioned at least one device or system achieves its function by the operation of the microprocessor in accordance with the computer program. Here, the computer program is composed of a combination of multiple instruction codes that indicate instructions to the computer in order to achieve a predetermined function.

[0110] (2) Some or all of the components constituting at least one of the above-described devices or systems may be made up of a single system LSI (Large Scale Integration). The system LSI is a multi-functional LSI manufactured by integrating multiple components onto a single chip, and specifically, it is a computer system comprising a microprocessor, ROM, RAM, etc. The RAM stores a computer program. The system LSI achieves its function by operating the microprocessor in accordance with the computer program.

[0111] (3) Some or all of the components constituting at least one of the above-described devices or systems may consist of an IC card or a standalone module that is detachable from the device or system. The IC card or module is a computer system consisting of a microprocessor, ROM, RAM, etc. The IC card or module may include the above-described multi-functional LSI. The IC card or module achieves its function by the operation of the microprocessor in accordance with a computer program. The IC card or module may be tamper-resistant.

[0112] (4) The disclosure may also be the methods described above. Alternatively, it may be a computer program that implements these methods using a computer, or a digital signal consisting of a computer program.

[0113] Furthermore, this disclosure may also refer to a computer program or digital signal recorded on a computer-readable recording medium, such as a flexible disk, hard disk, CD (Compact Disc)-ROM, DVD, DVD-ROM, DVD-RAM, BD (Blu-ray® Disc), semiconductor memory, etc. Alternatively, it may refer to a digital signal recorded on such a recording medium.

[0114] Furthermore, this disclosure may also include the transmission of computer programs or digital signals via telecommunications lines, wireless or wired communication lines, networks such as the Internet, data broadcasting, etc.

[0115] Alternatively, the program or digital signal may be carried out by another independent computer system by recording and transferring it on a recording medium, or by transferring the program or digital signal via a network or the like. [Industrial applicability]

[0116] This disclosure has the effect of improving the efficiency of crystal structure exploration and is useful for equipment and systems for materials development. [Explanation of Symbols]

[0117] 1. Information Processing System 100 Information Processing Devices 101 Acquisition Department 102 Classification Department 103 1st generation part 104 Second generation part 105 Output section 200 Input section 211 Composition formula input field 212 First Elemental Assortment Field 213 Second Elemental Assortment Field 214 Execute button 300 Display 310, 311 Input Acceptance Screen 320 Output screen DA elemental information database input reception information DC output information

Claims

1. An information processing method performed by an information processing device, Obtain elemental information for two or more elements, By classifying the two or more elements mentioned above based on predetermined conditions, a first element set containing one or more elements and a second element set containing one or more elements are generated. A second crystal structure is generated by arranging the one or more elements contained in the second element set into a first crystal structure composed of the one or more elements contained in the first element set. Output information regarding the second crystal structure, Information processing methods.

2. The second crystal structure described above is an inorganic crystal structure or an ionic crystal structure. The information processing method according to claim 1.

3. The second crystal structure described above is a low-symmetry structure. The information processing method according to claim 1.

4. The aforementioned predetermined conditions include the condition of separating the two or more elements into anions and cations. The information processing method according to claim 1.

5. The one or more elements included in the first element set are anions, In the generation of the second crystal structure described above, further, A highly symmetrical structure composed of the aforementioned anions is generated as the first crystal structure. The information processing method according to claim 4.

6. In the generation of the second crystal structure described above, The second crystal structure is generated by arranging one or more of the elements included in the second element collection into each of the multiple vacancies included in the first crystal structure. The information processing method according to claim 1.

7. In the generation of the second crystal structure described above, An optimization process is performed on the arrangement of one or more elements included in the second element set. The information processing method according to claim 6.

8. In the generation of the second crystal structure described above, further, The first crystal structure is generated by arranging one or more of the elements included in the first element set according to the first space group. The information processing method according to claim 1.

9. In the generation of the second crystal structure described above, The one or more candidate second space groups for the first space group are restricted from N second space groups (where N is an integer greater than or equal to 2) to M second space groups (where M is an integer satisfying 1 < M < N), and one second space group included in the M second space groups is used as the first space group. The information processing method according to claim 8.

10. An acquisition unit that acquires elemental information for two or more types of elements, A classification unit that generates a first element set containing one or more elements and a second element set containing one or more elements by classifying the two or more elements based on predetermined conditions, A generating unit that generates a second crystal structure by arranging the one or more elements contained in the second element set in a first crystal structure composed of the one or more elements contained in the first element set, An output unit that outputs output information regarding the second crystal structure, An information processing system equipped with the following features.

11. An acquisition unit that acquires elemental information for two or more types of elements, It includes an output unit that outputs first image information and second image information to a display unit for display, The above-mentioned first image information is, The first crystal structure is composed of one or more elements from the two or more elements mentioned above that are included in the first element set. The second image information is, The second crystal structure is characterized in which one or more elements from the two or more elements mentioned above are arranged in the first crystal structure. Information processing system.

12. Obtain elemental information for two or more elements, By classifying the two or more elements mentioned above based on predetermined conditions, a first element set containing one or more elements and a second element set containing one or more elements are generated. A second crystal structure is generated by arranging the one or more elements contained in the second element set into a first crystal structure composed of the one or more elements contained in the first element set. Output information regarding the second crystal structure, A program that causes a computer to perform a task.

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