A Method, Device, and Storage Medium for Calculating the Energy of a Molecular Crystal

Abstract

The present application provides a method, apparatus and storage medium for calculating the energy of a molecular crystal. Among them, the method includes: obtaining a target crystal structure, and determining a central molecule, M clusters and M shell structures from the target crystal structure; calculating the molecular energy of the central molecule, the cluster energy of each cluster and the shell energy of each shell structure respectively by using quantum chemistry methods; calculating the lattice energy of the target crystal structure according to the molecular energy, the cluster energy and the shell energy; and calculating the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy. The technical solution of the present application can improve the calculation efficiency and calculation accuracy of crystal energy by establishing a "core-shell" calculation scheme.

Description

Technical Field

[0001] This application belongs to the technical field of molecular crystals, and particularly relates to a method, device, and storage medium for calculating the energy of molecular crystals. Background Art

[0002] Molecular crystals are structures formed by the stacking of organic molecules through non-bonding weak interactions. The accurate description of weak interactions usually requires high-precision methods with extremely high algorithmic complexity, and such methods are usually difficult to apply to molecular crystal systems with large systems. Molecular crystal calculations usually choose relatively inexpensive density functional theory methods, semi-empirical methods, or empirical force field methods. In order to apply high-precision methods to molecular crystals, the total energy of the crystal is usually decomposed into the sum of several subsystems.

[0003] Existing calculation schemes usually need to extract a large number of cluster structures from the crystal according to specific rules for two-body, three-body, or even four-body calculations. Usually, with the increase in precision and the consideration of many-body effects, the cluster scale and number increase rapidly, which results in a complex final calculation process and high cost.

[0004] Due to calculation resource limitations, existing calculation schemes usually discard clusters with smaller contributions according to certain rules, which may introduce certain errors. Moreover, in order to introduce the overall effect of the crystal, existing schemes usually use low-precision methods to calculate the crystal energy, which also introduces certain errors. Summary of the Invention

[0005] To solve or partially solve the problems existing in the related art, this application provides a method, device, and storage medium for calculating the energy of molecular crystals, which can improve the calculation efficiency and accuracy of crystal energy by establishing a "core-shell" calculation scheme.

[0006] The first aspect of this application provides a method for calculating the energy of molecular crystals, including:

[0007] Obtain a target crystal structure, and determine a central molecule, M clusters, and M shell structures from the target crystal structure, where M is an integer greater than or equal to 1;

[0008] Use quantum chemistry methods to calculate the molecular energy of the central molecule, the cluster energy of each cluster, and the shell energy of each shell structure respectively;

[0009] Calculate the lattice energy of the target crystal structure according to the molecular energy, the cluster energy, and the shell energy;

[0010] Calculate the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy.

[0011] Preferably, determining the central molecule, M clusters, and M shell structures from the target crystal structure includes:

[0012] Selecting a molecule from the target crystal structure as the central molecule;

[0013] Using the geometric center of the central molecule as the center of the sphere and taking M different preset radii as the truncation radii to respectively perform atomic truncation on the target crystal structure, and selecting the molecules with atoms within the truncation radius to construct clusters, obtaining M of the clusters;

[0014] Deleting the central molecule from each of the clusters to obtain the corresponding M shell structures.

[0015] Preferably, the selecting the molecules with atoms within the truncation radius to construct clusters includes:

[0016] Selecting the molecules with all atoms within the truncation radius to construct clusters; or,

[0017] If there are molecules with only some atoms within the truncation radius, performing a completion process on the molecules, and using the completed molecules and the molecules with all atoms within the truncation radius to construct clusters.

[0018] Preferably, calculating the molecular energy of the central molecule, the cluster energy of each of the clusters, and the shell energy of each of the shell structures respectively using a quantum chemistry method includes:

[0019] Taking the molecular structure of the central molecule as the input, and calculating the molecular energy of the central molecule and the sub - item energies constituting the molecular energy using a quantum chemistry method;

[0020] Taking the structure of each of the clusters as the input respectively, and calculating the cluster energy of each of the clusters and the sub - item energies constituting the cluster energy using the quantum chemistry method;

[0021] Taking each of the shell structures as the input respectively, and calculating the shell energy of each of the shell structures and the sub - item energies constituting the shell energy using the quantum chemistry method.

[0022] Preferably, the quantum chemistry method includes the tight - binding DFTB method based on density functional theory, and the energy calculation formula is:

[0023] E 能量 =E 0近似 +E scc +E rep +E nuc +E disp_corr ;

[0024] Among them, the sub - item energy E0近似 , E scc , E rep , E nuc , E disp_corr are respectively: the orbital energy under zero-order approximation, the second / third-order electrostatic energy, the short-range repulsive energy of valence bonds, the nuclear repulsive energy, and the long-range dispersion correction energy.

[0025] Preferably, the quantum chemical method includes the density functional theory (DFT) method, and the energy calculation formula is:

[0026] E 能量 = E0 + E j + E x + E c + E nuc + E disp_corr ;

[0027] Among them, the partial energies E0, E j , E x , E c , E nuc , E disp_corr are respectively: the orbital energy, the electron electrostatic energy, the exchange energy, the correlation energy, the nuclear repulsive energy, and the long-range dispersion correction energy.

[0028] Preferably, calculating the lattice energy of the target crystal structure according to the molecular energy, the cluster energy, and the shell energy includes:

[0029] Calculating the partial energies of the interaction energy between the central molecule and each shell structure according to the partial energies of the molecular energy, the partial energies of each cluster energy, and the partial energies of each shell energy by using a first preset formula;

[0030] Calculating the partial energies of the lattice energy of the target crystal structure according to the partial energies of the interaction energy between the central molecule and each shell structure by using a second preset formula;

[0031] Calculating the lattice energy of the target crystal structure according to the partial energies of the lattice energy and the contribution coefficients of the partial energies by using a third preset formula.

[0032] Preferably, the first preset formula is:

[0033] E 壳n相互作用能,i = E 团簇n,i – E 分子,i – E 壳n,i ;

[0034] Among them, n is the cluster number, the value of n is 1 to M, i is the number of the partial energy, and E 团簇n,iis the i-th sub-item energy of the cluster energy of the n-th cluster, and the E 分子,i is the i-th sub-item energy of the molecular energy of the central molecule, and the E 壳n,i is the i-th sub-item energy of the shell energy of the n-th shell structure, and the E 壳n相互作用能,i is the i-th sub-item energy of the interaction energy between the central molecule and the n-th shell structure.

[0035] Preferably, when the M is greater than or equal to 3, the second preset formula is:

[0036] E 壳n相互作用能.i = E 晶格,i + A * (R n ) -B ;

[0037] wherein, the E 晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, the R n is the truncation radius used when constructing the n-th cluster, and the A and the B are two different attenuation coefficients;

[0038] Calculating the i-th sub-item energies of the lattice energy of the target crystal structure according to the i-th sub-item energies of the interaction energy between the central molecule and each shell structure by using the second preset formula includes:

[0039] Calculating the i-th sub-item energies of the interaction energy between the central molecule and each shell structure by using the second preset formula to obtain multiple groups of E 晶格,i , A and B;

[0040] Fitting multiple groups of E 晶格,i , A and B to obtain the i-th sub-item energies of the lattice energy of the target crystal structure.

[0041] Preferably, when the M is 2, the second preset formula is:

[0042] E 晶格，i = [E 壳1相互作用能,i (R1) 3 - E 壳2相互作用能,i (R2) 3 / [(R1) 3 -(R2) 3 ;

[0043] wherein, the E 晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, E 壳1相互作用能,i is the i-th sub-item energy of the interaction energy between the central molecule and the 1st shell structure, E 壳2相互作用能,iis the i-th sub-item energy of the interaction energy between the central molecule and the second shell structure, where R1 is the truncation radius used when constructing the first cluster, and R2 is the truncation radius used when constructing the second cluster.

[0044] Preferably, when M is 1, n is 1, and the second preset formula is:

[0045] E 晶格,i = E 壳1相互作用能,i ;

[0046] where E 晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, and E 壳1相互作用能,i is the i-th sub-item energy of the interaction energy between the central molecule and the shell structure.

[0047] Preferably, the third preset formula is:

[0048] E 晶格 = sum(k i E 晶格,i );

[0049] where E 晶格 is the lattice energy of the target crystal structure, E 晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, and k i is the contribution coefficient of the i-th sub-item energy of the lattice energy.

[0050] Preferably, the calculation method of the contribution coefficients of the sub-item energies of the lattice energy includes:

[0051] Obtain multiple reference crystal structures and the sub-item energies of the reference lattice energy of each reference crystal structure;

[0052] Calculate the sub-item energies of the lattice energy of each reference crystal structure respectively;

[0053] Set the contribution coefficients of the sub-item energies of the lattice energy;

[0054] According to the sub-item energies of the lattice energy of each reference crystal structure and the set contribution coefficients, obtain the sub-item energies of the predicted lattice energy of each reference crystal structure;

[0055] Use the sub-item energies of the reference lattice energy and the sub-item energies of the predicted lattice energy of each reference crystal structure to fit the set contribution coefficients to obtain the contribution coefficients of the sub-item energies after fitting.

[0056] Preferably, calculating the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy includes:

[0057] Performing energy correction on the molecular energy to obtain the corrected molecular energy;

[0058] Calculating the total crystal energy of the target crystal structure by using the corrected molecular energy and the lattice energy.

[0059] A second aspect of the present application provides a method for comparing molecular crystal energies, including:

[0060] Obtaining at least two crystal structures to be compared;

[0061] Calculating the crystal energy of each crystal structure by using the molecular crystal energy calculation method provided in the first aspect of the present application to obtain the total crystal energy of each crystal structure;

[0062] Determining the magnitude relationship of the crystal energies of the at least two crystal structures according to the total crystal energy of each crystal structure.

[0063] A third aspect of the present application provides a molecular crystal energy calculation device, including:

[0064] An acquisition module, configured to acquire a target crystal structure and determine a central molecule, M clusters, and M shell structures from the target crystal structure, where M is an integer greater than or equal to 1;

[0065] A first calculation module, configured to calculate the molecular energy of the central molecule, the cluster energy of each cluster, and the shell energy of each shell structure respectively by using a quantum chemistry method;

[0066] A second calculation module, configured to calculate the lattice energy of the target crystal structure according to the molecular energy, the cluster energy, and the shell energy;

[0067] A third calculation module, configured to calculate the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy.

[0068] A fourth aspect of the present application provides a molecular crystal energy comparison device, including:

[0069] An acquisition module, configured to acquire at least two crystal structures to be compared;

[0070] A calculation module, configured to calculate the crystal energy of each crystal structure by using the molecular crystal energy calculation device provided in the third aspect of the present application to obtain the total crystal energy of each crystal structure;

[0071] A determination module, configured to determine the crystal energy magnitude relationship of the at least two crystal structures according to the total crystal energy of each of the crystal structures.

[0072] A fifth aspect of the present application provides an electronic device, including:

[0073] A processor; and

[0074] A memory, on which executable code is stored, and when the executable code is executed by the processor, the processor is caused to execute the molecular crystal energy calculation method provided in the first aspect of the present application or the molecular crystal energy comparison method provided in the second aspect of the present application.

[0075] A sixth aspect of the present application provides a computer-readable storage medium, on which executable code is stored, and when the executable code is executed by a processor of an electronic device, the processor is caused to execute the molecular crystal energy calculation method provided in the first aspect of the present application or the molecular crystal energy comparison method provided in the second aspect of the present application.

[0076] The technical solution provided by the present application, after obtaining the target crystal structure, can determine the central molecule, at least one cluster structure and the corresponding shell structure therefrom, and respectively calculate the molecular energy of the central molecule, the cluster energy of each cluster structure and the shell energy of each shell structure by using quantum chemistry methods. Based on the above energies, the lattice energy of the target crystal structure is calculated, and then the total crystal energy of the target crystal structure is calculated by using the molecular energy of the central molecule and the lattice energy. By calculating the energies of the central molecule (nucleus) and the clusters (shells), the present application establishes a "nucleus-shell" calculation scheme, which can avoid the calculation of a large number of many-body clusters such as two-body and three-body in the prior art, can obtain higher energy accuracy than directly using low-precision calculation methods originally, and the calculation efficiency is also greatly improved. Description of the Drawings

[0077] By describing the exemplary embodiments of the present application in more detail in conjunction with the drawings, the above and other objects, features and advantages of the present application will become more obvious, wherein, in the exemplary embodiments of the present application, the same reference numerals generally represent the same components.

[0078] Figure 1 is a schematic flowchart of a molecular crystal energy calculation method provided by an embodiment of the present application;

[0079] Figure 2 is a structural diagram of a central molecule in an Aspirin crystal provided by an embodiment of the present application;

[0080] Figure 3 is based on Figure 2The molecular structure diagram after atomic truncation with the central molecule in [[ ]] as the center of the sphere and R1 as the truncation radius;

[0081] Figure 4 is the structure diagram of cluster 1 after molecular completion of the molecular structure of [[ ]]; Figure 3

[0082] Figure 5 is with [[ ]] Figure 2 the central molecule in [[ ]] as the center of the sphere, and the structure diagram of cluster 2 after atomic truncation and completion with R2 as the truncation radius;

[0083] Figure 6 is the structural schematic diagram of a molecular crystal energy calculation device provided by an embodiment of the present application;

[0084] Figure 7 is the structural schematic diagram of an electronic device provided by an embodiment of the present application. Specific Embodiments

[0085] Hereinafter, the embodiments of the present application will be described in more detail with reference to the accompanying drawings. Although the embodiments of the present application are shown in the drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to make the present application more thorough and complete, and to fully convey the scope of the present application to those skilled in the art.

[0086] The terms used in the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms of "a", "the" and "said" used in the present application and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0087] It should be understood that although the terms "first", "second", "third", etc. may be used in the present application to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present application, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present application, "a plurality" means two or more unless otherwise specifically defined.

[0088] ​In the related art, when calculating the energy of a crystal, a large number of cluster structures are usually extracted from the crystal for two-body, three-body, or even four-body calculations. However, with the increasing accuracy requirements and the consideration of many-body effects, the cluster scale and number increase rapidly, which will result in a complex calculation process and high costs. Moreover, currently, low-precision methods are mostly used to calculate the energy of the crystal, which also introduces certain errors.

[0089] In view of the above problems, the embodiments of the present application provide a method, device, and storage medium for calculating the energy of a molecular crystal. By establishing a "core-shell" calculation scheme, the calculation efficiency and accuracy of the crystal energy can be improved.

[0090] The technical solutions of the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0091] The embodiments of the present application provide a method for calculating the energy of a molecular crystal. As Figure 1 shown, the method may include the following steps:

[0092] S110. Obtain a target crystal structure, and determine a central molecule, M clusters, and M shell structures from the target crystal structure. Here, M may be an integer greater than or equal to 1.

[0093] The target crystal structure may be a crystal structure composed of a single molecule or a crystal structure composed of multiple molecules, which is not limited herein.

[0094] In an implementation manner, the specific implementation manner of determining a central molecule, M clusters, and M shell structures from the target crystal structure may include: selecting a molecule from the target crystal structure as the central molecule; taking the geometric center of the central molecule as the center of the sphere, and respectively performing atomic interception on the target crystal structure with M different preset radii as the truncation radii, and selecting the molecules with atoms located within the truncation radius to construct clusters, obtaining M clusters; deleting the central molecule from each cluster to obtain the corresponding M shell structures.

[0095] If the target crystal structure is a crystal structure composed of a single molecule, a molecule can be randomly selected from the target crystal structure as the central molecule, or a molecule can be selected from near the geometric center of the target crystal structure as the central molecule.

[0096] If the target crystal structure is a crystal structure composed of two molecules (such as molecule A and molecule B), the molecule A and molecule B that are closest to each other (the distance between the geometric centers of the molecules is the shortest) can be selected from the target crystal structure as the central molecule together.

[0097] Further, when constructing a cluster, molecules with all atoms located within the truncation radius can be selected to construct the cluster, while excluding molecules with only some atoms located within the truncation radius;

[0098] Alternatively, if only some atoms of a molecule are within the truncation radius, the molecule can be completed, and clusters can be constructed using the completed molecule and the molecules with all atoms within the truncation radius. That is, a sphere is drawn with the geometric center of the central molecule and radius R, all atoms within the radius R are selected, and it is ensured that the sphere contains at least all the atoms on the first-nearest neighbor molecules of the central molecule. According to the crystal arrangement, the atoms are supplemented to form complete molecules, and this set of molecules is the "cluster", and the cluster without the central molecule is the "shell".

[0099] S120. Calculate the molecular energy of the central molecule, the cluster energy of each cluster, and the shell energy of each shell structure using quantum chemical methods respectively.

[0100] Specifically, the molecular structure of the central molecule can be used as the input, and the molecular energy of the central molecule and the sub-item energies that make up the molecular energy can be calculated using quantum chemical methods; the structure of each cluster is used as the input respectively, and the cluster energy of each cluster and the sub-item energies that make up the cluster energy are calculated using the same quantum chemical method; the structure of each shell structure is used as the input respectively, and the shell energy of each shell structure and the sub-item energies that make up the shell energy are calculated using the same quantum chemical method.

[0101] In one embodiment, the quantum chemical method may include the Density Functional based Tight Binding (DFTB) method based on density functional theory. The calculation methods of the above energies can all adopt the following formula:

[0102] E 能量 =E 0近似 +E scc +E rep +E nuc +E disp_corr ; (1-1)

[0103] Wherein, the sub-item energy E 0近似 is the orbital energy under the zero-order approximation, E scc is the second / third-order electrostatic energy, E rep is the short-range repulsive energy of the valence bond, E nuc is the nuclear repulsive energy, E disp_corr is the long-range dispersion correction energy. Since E nuc is defaulted to an exact value and does not require additional correction, here E nuc and E rep can be combined, or E nuc can be directly ignored, that is, formula (1-1) can be expressed as: E 能量 =E 0近似 +E scc +Erep +E disp_corr 。

[0104] In one embodiment, the quantum chemistry method may include a Density Functional Theory (DFT) method, and the calculation methods of the above energies may all adopt the following formula:

[0105] E 能量 = E0 + E j + E x + E c + E nuc + E disp_corr ; (1-2)

[0106] wherein, each sub-item energy E0 is the orbital energy, E j is the electronic electrostatic energy, E x is the exchange energy, E c is the correlation energy, E nuc is the nuclear repulsion energy, E disp_corr is the long-range dispersion correction energy.

[0107] It can be understood that in addition to the above DFTB and DFT methods, the quantum chemistry method can also adopt other semi-empirical methods or empirical force field methods, etc., which are not limited here.

[0108] Here, DFTB is taken as an example for further illustration. Taking the molecular structure of the central molecule as the input, the molecular energy of the central molecule and its each sub-item energy are calculated by using formula (1-1).

[0109] Taking the geometric center of the central molecule as the center of the sphere, the target crystal structure is atomically intercepted with a preset radius R1 as the cut-off radius, and the molecules with atoms within the range of the preset radius R1 are formed into a cluster to obtain cluster 1; taking the structure of cluster 1 as the input, the cluster energy of cluster 1 and its each sub-item energy are calculated by using formula (1-1) in the same way; deleting the central molecule from cluster 1 to obtain the shell 1 structure, taking the shell 1 structure as the input, and the shell energy of the shell 1 structure and its each sub-item energy are calculated by using formula (1-1) in the same way.

[0110] Still taking the geometric center of the central molecule as the center of the sphere, the target crystal structure is atomically intercepted with a preset radius R2 as the cut-off radius, and the molecules with atoms within the range of the preset radius R2 are formed into a cluster to obtain cluster 2; taking the structure of cluster 2 as the input, the cluster energy of cluster 2 and its each sub-item energy are calculated by using formula (1-1) in the same way; deleting the central molecule from cluster 2 to obtain the shell 2 structure, taking the shell 2 structure as the input, and the shell energy of the shell 2 structure and its each sub-item energy are calculated by using formula (1-1) in the same way.

[0111] Still taking the geometric center of the central molecule as the center of the sphere and using the preset radius R3 as the truncation radius to intercept atoms from the target crystal structure, molecules with atoms within the range of the preset radius R3 are formed into a cluster to obtain cluster 3; taking the structure of cluster 3 as the input, the cluster energy of cluster 3 and its respective sub-item energies are calculated using formula (1-1) in the same way; the central molecule is deleted from cluster 3 to obtain the shell 3 structure, taking the shell 3 structure as the input, and the shell energy of the shell 3 structure and its respective sub-item energies are calculated using formula (1-1) in the same way.

[0112] S130. Calculate the lattice energy of the target crystal structure based on the molecular energy, cluster energy, and shell energy.

[0113] In the embodiments of the present application, the interaction energy between the central molecule and each shell structure can be determined using the molecular energy of the central molecule, the cluster energy of each cluster, and the shell energy of each shell structure, and then the lattice energy of the target crystal structure can be obtained by extrapolating using the interaction energy.

[0114] In one embodiment, the sub-item energies of the interaction energy between the central molecule and each shell structure can be calculated using the first preset formula based on the sub-item energies of the molecular energy, the sub-item energies of each cluster energy, and the sub-item energies of each shell energy; further, the sub-item energies of the lattice energy of the target crystal structure can be calculated using the second preset formula based on the sub-item energies of the interaction energy between the central molecule and each shell structure; and then the lattice energy of the target crystal structure can be calculated using the third preset formula based on the sub-item energies of the lattice energy and the contribution coefficients of the sub-item energies.

[0115] In this embodiment, the representation form of the first preset formula is as follows:

[0116] E 壳n相互作用能,i = E 团簇n,i – E 分子,i – E 壳n,i ; (1-3)

[0117] Among them, n is the cluster number, and the value of n ranges from 1 to M. i is the number of the sub-item energy. Taking the DFTB method as an example, when i is 1, the corresponding sub-item energy is E 0近似 ; when i is 2, the corresponding sub-item energy is E scc ; when i is 3, the corresponding sub-item energy is E rep ; when i is 4, the corresponding sub-item energy is E nuc ; when i is 5, the corresponding sub-item energy is E disp_corr . E 团簇n,i is the i-th sub-item energy of the cluster energy of the n-th cluster, E 分子,iThe i-th sub - energy of the molecular energy of the central molecule, E 壳n,i The i-th sub - energy of the shell energy of the n-th shell structure, E 壳n相互作用能,i The i-th sub - energy of the interaction energy between the central molecule and the n-th shell structure.

[0118] For example, according to formula (1 - 3), the representation of the i-th sub - energy of the interaction energy between the central molecule and the 1st shell structure (shell 1 structure) is: E 壳1相互作用能,i = E 团簇1,i – E 分子,i – E 壳1,i . The representation of the i-th sub - energy of the interaction energy between the central molecule and the 2nd shell structure (shell 2 structure) is: E 壳2相互作用能,i = E 团簇2,i – E 分子,i – E 壳2,i .

[0119] Considering that the interaction energy between the shell structure and the central molecule under different cut - off radii (R n ) may have a decay situation, and the decay conforms to a decay function related to R n . In one embodiment, when M is greater than or equal to 3, the second preset formula can be expressed as follows:

[0120] E 壳n相互作用能.i = E 晶格,i + A*(R n ) -B ; (1 - 4)

[0121] Wherein, E 晶格,i is the i-th sub - energy of the lattice energy of the target crystal structure, R n is the cut - off radius used when constructing the n-th cluster, A and B are two different decay coefficients, and both A and B are unknown.

[0122] Correspondingly, the sub - energies of the interaction energy between the central molecule and each shell structure can be calculated using the second preset formula to obtain multiple groups of E 晶格,i , A and B; and multiple groups of E 晶格,i , A and B are fitted to obtain the sub - energies of the lattice energy of the target crystal structure.

[0123] Using E 壳n相互作用能.i for energy extrapolation to obtain E 晶格,i . For extrapolation, in formula (1 - 4), E 壳n相互作用能.i and R n are known, E 晶格,i , A and B are unknown. Therefore, the interaction energy between 3 shell structures and the central molecule can be used for E 晶格,i, A and B are solved, and finally E is obtained 晶格,i . For the case where the number of shell structures is greater than 3 (M > 3), a set of E, 晶格,i , A and B can be obtained corresponding to every three shell structures, so as to obtain multiple sets of E, 晶格,i , A and B. Then, for the multiple sets of E, 晶格,i , A and B are subjected to fitting optimization, and finally E is obtained 晶格,i . Preferably, the fitting optimization of the multiple sets of E, 晶格,i , A and B can be to calculate the average value of the multiple sets of E, 晶格,i , A and B respectively. Since the larger the number of clusters (or shell structures), the larger R n becomes, resulting in a rapid increase in the amount of calculation. To reduce the amount of calculation and improve the calculation efficiency, in the embodiments of the present application, M is preferably within 3, that is, no more than 3 clusters.

[0124] It can be understood that in addition to using formula (1-4), other attenuation functions can also be used for the attenuation function, such as the following two representation functions:

[0125] E 壳n相互作用能,i = E 晶格,i + A * exp(-B * R n );

[0126] E 壳n相互作用能,i = E 晶格,i + A * exp[-B * sqrt(R n )];

[0127] In the above two functions, A and B are two different attenuation coefficients, and both A and B are unknown. The calculation process of E 晶格,i can be similar to the calculation process of formula (1-4), which will not be elaborated here.

[0128] For formula (1-4), usually B can be regarded as a physically determined parameter, and its theoretical value can be set to 3.0. Therefore, only E 晶格,i and A are unknown in formula (1-4). In one embodiment, when M = 2, the second preset formula can be transformed from formula (1-4) into the following formula (1-5):

[0129] E 晶格,i = [E 壳1相互作用能,i (R1) 3 - E 壳2相互作用能,i (R2) 3 / [(R1) 3 -(R2) 3 ; (1-5)

[0130] Among them, E 晶格,iis the i-th sub - item energy of the lattice energy of the target crystal structure, E 壳1相互作用能,i is the i-th sub - item energy of the interaction energy between the central molecule and the first shell structure, E 壳2相互作用能,i is the i-th sub - item energy of the interaction energy between the central molecule and the second shell structure, R1 is the truncation radius used when constructing the first cluster, and R2 is the truncation radius used when constructing the second cluster.

[0131] At this time, only 2 clusters can be used for extrapolation, and E 晶格,i can be calculated. While ensuring the calculation accuracy, the calculation efficiency can be further improved.

[0132] In one embodiment, the case of only considering using 1 cluster structure for calculating the shell interaction energy can be considered. At this time, extrapolation cannot be performed, but the sub - items can still be used for fitting to obtain E 晶格,i .

[0133] Specifically, when M is 1, n is also 1. At this time, the second preset formula can be expressed as follows:

[0134] E 晶格,i = E 壳1相互作用能,i = E 团簇1,i – E 分子,i – E 壳1,i ; (1 - 6)

[0135] Among them, E 晶格,i is the i-th sub - item energy of the lattice energy of the target crystal structure, E 壳1相互作用能,i is the i-th sub - item energy of the interaction energy between the central molecule and the shell structure.

[0136] In one embodiment, the representation form of the third preset formula is as follows:

[0137] E 晶格 = sum(k i E 晶格,i ); (1 - 7)

[0138] Among them, E 晶格 is the lattice energy of the target crystal structure, E 晶格,i is the i-th sub - item energy of the lattice energy of the target crystal structure, k i is the contribution coefficient of the i-th sub - item energy of the lattice energy.

[0139] In this embodiment, the contribution coefficients of the sub - item energies of the lattice energy can be set empirical values, or can be calculated by calculating a certain number of E 壳n相互作用能.i before the crystal energy calculation and combined with experiments or high - precision lattice energies for fitting and determination.

[0140] Although the direct summation of the extrapolated lattice energy components should physically be equal to the lattice energy, it has been found in practical applications that: a) Although the overall energy may be the same, different methods show different trends in the performance of the components; b) The energy differences in the components may lead to large errors in the calculation of the lattice energy. Therefore, here the experimental lattice energy or high-precision lattice energy is used as a reference to recalibrate each lattice energy component of the lower-precision method to obtain a lattice energy closer to the reference.

[0141] The following are the specific implementation manners for fitting to determine the contribution coefficients of each component energy:

[0142] 1) Obtain a plurality of reference crystal structures and the reference lattice energy of each reference crystal structure.

[0143] Among them, N reference crystal structures and the reference lattice energy E of these reference crystal structures can be collected from past experimental results, literature reports, and / or structure databases ref,j , where j is from 1 to N. The reference crystal structure refers to a force-converged crystal structure predicted by a theoretical method (such as DFT, DFTB, etc.) or an experimental crystal structure, and the reference lattice energy is the crystal lattice energy predicted by a high-precision theoretical method (such as DFT) or an experimental measurement value.

[0144] 2) Calculate the component energies of the lattice energy of each reference crystal structure respectively.

[0145] Using the same calculation method as that for obtaining the component energies of the lattice energy of the target crystal structure described above, calculate the component energies of the lattice energy of each reference crystal structure. Taking DFTB as an example, taking each reference crystal structure as an input, through the above series of calculations, the component energies of the lattice energy of each reference crystal structure can be obtained: E 晶格,0近似 、E 晶格,scc 、E 晶格,rep 、E 晶格,disp_corr 、E nuc .

[0146] Furthermore, the component energies E 晶格，i of the lattice energy of the N reference crystal structures can be organized into a matrix, and the representation form of this matrix (X) is as follows:

[0147]

[0148] And, the reference lattice energy E ref，j of each reference crystal structure can be represented in vector form:

[0149] E = [E ref，1 E ref，2 ... E ref，N T ​;

[0150] 3) Set the contribution coefficient k of each sub - item energy of the lattice energy i 。

[0151] The contribution coefficient k i is a parameter to be determined, which can be represented in vector form as:

[0152] K = [k 0近似 k scc k rep k disp_corr k nuc T ;

[0153] Since E nuc is an exact value and does not need to be recalibrated, the above vector K can be modified to:

[0154] K = [k 0近似 k scc k rep k disp_corr 1] T ;

[0155] 4) According to each sub - item energy of the lattice energy of each reference crystal structure and the set contribution coefficient, obtain each sub - item energy of the predicted lattice energy of each reference crystal structure.

[0156] Ideally, E = XK; in actual situations, E* = XK. Among them, E* contains each sub - item energy of the predicted lattice energy of each reference crystal structure.

[0157] 5) Use each sub - item energy of the reference lattice energy and each sub - item energy of the predicted lattice energy of each reference crystal structure to fit the set contribution coefficient, and obtain the contribution coefficient of each sub - item energy after fitting.

[0158] By adjusting K, make E* close to E. When the error (such as root - mean - square error RMSE, mean - square error MSE, etc.) between E* and E is minimized, K is obtained. In practical applications, the number N of reference crystal structures is usually much larger than the number i of sub - item energies. Therefore, an optimization algorithm (such as the least - squares method) can be used to directly fit K.

[0159] S140. Calculate the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy.

[0160] In the embodiments of the present application, after obtaining the molecular energy of the central molecule and the lattice energy of the target crystal structure, the sum of the two energies can be calculated to obtain the total crystal energy of the target crystal structure. The specific calculation formula is as follows:

[0161] E​总能 = E 分子 + E 晶格 = E 分子 + sum(k i E 晶格,i ); (1 - 8)

[0162] Among them, E 总能 is the total crystal energy of the target crystal structure, E 分子 is the molecular energy of the central molecule, and E 晶格 is the lattice energy of the target crystal structure.

[0163] Here, the Aspirin crystal is taken as an example for illustration. The Aspirin crystal has P21 / c symmetry, and one unit cell contains 4 equivalent molecules. In this example, the low-precision DFTB method is selected for extrapolation of the 2-shell structure to predict the total crystal energy. According to the literature report, the lattice energy of this Aspirin calculated by the high-precision DFT method is -118 kJ / mol.

[0164] 1) Select one of the 4 equivalent molecules as the central molecule, and calculate E 分子,0近似 , E 分子,scc , E 分子,rep , E 分子,disp_corr . Among them, the molecular structure of the central molecule in the Aspirin crystal is as Figure 2 shown.

[0165] 2) Use R1 = 4.0 Å as the cut-off radius, with the geometric center of the central molecule as the center of the sphere, and perform atomic selection, as Figure 3 shown. The structure of all atoms within the cut-off radius R1 is shown in the figure. It can be seen from the figure that the peripheral molecules are incomplete, so a molecular completion operation is required;

[0166] 3) Complete the incomplete molecules to obtain cluster 1 and shell 1 structures. Figure 4 The structure of cluster 1 after completing the molecules is shown as follows. The structure of the ball-and-stick model represents the central molecule, and the remaining wire model part is the shell 1 structure.

[0167] 4) Use R2 = 8.0 Å as the cut-off radius, and repeat steps 2) and 3) above to obtain cluster 2 and shell 2 structures. Figure 5 The structure of the completed cluster 2 is shown as follows. The structure of the ball-and-stick model represents the central molecule, and the remaining wire model part is the shell 2 structure.

[0168] 5) Calculate the respective partial energies of the central molecule, cluster 1, cluster 2, shell 1, and shell 2 structures by the DFTB method under the 3OB parameters to obtain E 分子,i , E 团簇1,i , E 壳1,i , E团簇2,i and E 壳2,i , as shown in Table 1:

[0169] Table 1 Sub - item energies calculated by the DFTB method under 3OB parameters (unit: a.u.)

[0170]

[0171] 6) Using formula (1 - 3), calculate to obtain E 壳1相互作用能,i and E 壳2相互作用能,i . In addition, extrapolate using formula (1 - 5) to obtain the sub - item energies of the lattice energy. The sub - item energy data are shown in Table 2.

[0172] Table 2 Sub - item energies extrapolated by the DFTB method under 3OB parameters (unit: a.u.)

[0173]

[0174] 7) Select the pre - fitted K for DFTB DFTB,壳1 / 2 , and use formula (1 - 7) to obtain E 晶格 . Obtain E 晶格 = - 119.8 kJ / mol using the parameters determined for DFTB / 3OB in Table 2, which is very close to the reported value in the literature.

[0175] 8) Calculate the total crystal energy using formula (1 - 8). According to the above lattice energy, the total crystal energy of the Aspirin crystal in the current method is: - 83023.0 kJ / mol.

[0176] Still taking the Aspirin crystal as an example for illustration, this Aspirin crystal has P21 / c symmetry, and one unit cell contains 4 equivalent molecules. In this example, the combination of the PBE - D3BJ method with normal precision and the 6 - 31G* basis set in the density functional theory (DFT) method is selected to predict the crystal energy of the 1 - shell structure.

[0177] 1) Select one of the 4 equivalent molecules as the central molecule, and calculate E 分子,0 , E 分子,j , E 分子,x , E 分子,c , E 分子,nuc , E 分子,disp_corr . The molecular structure of the central molecule is as Figure 2 shown.

[0178] 2) Use R1 = 4.0 Å as the cut - off radius, and with the geometric center of the central molecule as the center of the sphere, perform atomic selection, as Figure 3As shown, the structure of the ball-and-stick model is represented as the central molecule. For the atoms selected with a cutoff radius of 4.0 Å, it can be seen that the peripheral molecules are incomplete and need to be completed.

[0179] 3) Complete the incomplete molecules to obtain the cluster 1 and shell 1 structures, as Figure 4 shown. For the cluster 1 structure after completing the molecules, the structure of the ball-and-stick model is the central molecule, and the rest is the shell 1 structure.

[0180] 4) Use the PBE-D3BJ method and def-SV(P) to calculate the respective component energies of the central molecule, cluster 1, and shell 1 structures to obtain E 分子,i 、E 团簇1,i 、E 壳1,i , and its calculation method can be seen in formula (1-2), and use formula (1-3) to calculate E 壳1相互作用能,i . The respective component energies are shown in Table 3: Table 3 shows the various components and current parameters obtained under PBE-D3BJ and def-SV(P).

[0181] Table 3 Component energies obtained under PBE-D3BJ and def-SV(P) (unit: a.u.)

[0182]

[0183]

[0184] 5) Select K PBE-D3BJ / 6-31G*,壳1 previously fitted for the PBE-D3BJ method and def-SV(P), and use formula (1-7) to obtain E 晶格 = -117.1 kJ / mol, which is also very close to the results of high-precision calculations reported in the literature.

[0185] 6) Calculate the total crystal energy using formula (1-8). According to the above lattice energy, the total crystal energy of the Aspirin crystal in the current method is: -1700088.5 kJ / mol.

[0186] In one embodiment, the molecular energy of the central molecule can be first corrected to obtain the corrected molecular energy; then, using the corrected molecular energy and the lattice energy, the total crystal energy of the target crystal structure can be calculated.

[0187] For example, both the molecular energy and the lattice energy are calculated using the DFTB method. Subsequently, a method with higher precision (such as the MP2 / aug-cc-pVQZ method) can be used to recalculate the molecular energy of the central molecule, replacing the molecular energy calculated by the low-precision method (DFTB) previously, so as to obtain a more reliable molecular energy, and then obtain a more confident total crystal energy to further improve the calculation accuracy.

[0188] It can be understood that other correction methods can also be adopted. For example, at least one sub-item energy of the molecular energy is corrected to obtain a more reliable molecular energy.

[0189] The method provided by the embodiments of the present application can avoid the calculation of a large number of two-body, three-body and other many-body clusters in the prior art by calculating the energy of the central molecule (nucleus) and the cluster (shell), establishing a "nucleus-shell" calculation scheme, and can obtain higher energy accuracy than directly using the low-precision calculation method originally, and the calculation efficiency is also greatly improved.

[0190] The technology of using the central molecule-peripheral cluster for crystal energy evaluation in the present application is compatible with mainstream quantum chemistry calculation methods, can better balance the calculation accuracy and cost, and can be used for the rapid calculation of crystal energy.

[0191] The present application can directly use a large cluster for calculation, reducing the number of calculations and avoiding the steps of dividing, screening and calculating small clusters such as two-body in the existing methods.

[0192] All calculations of the present application can be carried out at the same calculation accuracy. By introducing multiple empirical parameters according to the energy terms with different physical origins, a relatively high-precision total crystal energy can be obtained.

[0193] The present application can select different-precision methods for combination for the central molecule and the shell structure, and perform different high-precision treatments on the molecular energy and the lattice energy respectively to obtain a more reliable total crystal energy.

[0194] In principle, the present application uses the calculation results of two shells for extrapolation. In actual use, the cluster can be directly fitted with a low-precision method to directly obtain the lattice energy, further improving the overall calculation efficiency.

[0195] The embodiments of the present application also provide a method for comparing the energies of molecular crystals, including the following steps:

[0196] S210. Obtain at least two crystal structures to be compared.

[0197] S220. Use the molecular crystal energy calculation method provided in the foregoing embodiments to calculate the crystal energy of each crystal structure, and obtain the total crystal energy of each crystal structure.

[0198] S230. Determine the crystal energy magnitude relationship of the at least two crystal structures according to the total crystal energy of each crystal structure.

[0199] By using the above method, the crystal energy of multiple crystal structures can be calculated quickly and accurately, and the energy of these crystal structures can be sorted to determine the crystal energy magnitude relationship of each crystal structure, which is convenient for quickly selecting relatively stable crystal structures from them in subsequent applications.

[0200] The embodiment of the present application also provides a molecular crystal energy calculation device, which can be used to execute the molecular crystal energy calculation method provided in the foregoing embodiment. As Figure 6 shown, the device may include:

[0201] An acquisition module 610, configured to acquire a target crystal structure, and determine a central molecule, M clusters, and M shell structures from the target crystal structure, where M is an integer greater than or equal to 1;

[0202] A first calculation module 620, configured to calculate the molecular energy of the central molecule, the cluster energy of each cluster, and the shell energy of each shell structure respectively by using a quantum chemistry method;

[0203] A second calculation module 630, configured to calculate the lattice energy of the target crystal structure according to the molecular energy, the cluster energy, and the shell energy;

[0204] A third calculation module 640, configured to calculate the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy.

[0205] Optionally, the implementation manner in which the acquisition module 610 determines a central molecule, M clusters, and M shell structures from the target crystal structure may include: selecting a molecule from the target crystal structure as the central molecule; using the geometric center of the central molecule as the center of the sphere, and using M different preset radii as truncation radii to perform atomic truncation on the target crystal structure respectively, and selecting the molecules with atoms within the truncation radius to construct clusters, obtaining M clusters; deleting the central molecule from each cluster to obtain the corresponding M shell structures.

[0206] Optionally, the implementation manner in which the acquisition module 610 selects the molecules with atoms within the truncation radius to construct clusters may include: selecting the molecules with all atoms within the truncation radius to construct clusters; or, if there are molecules with only some atoms within the truncation radius, performing a complementation process on the molecules, and using the complemented molecules and the molecules with all atoms within the truncation radius to construct clusters.

[0207] Optionally, the first calculation module 620 may further include:

[0208] The first calculation unit is configured to take the molecular structure of the central molecule as an input, and calculate the molecular energy of the central molecule and the respective sub - item energies that make up the molecular energy by using quantum chemical methods;

[0209] The second calculation unit is configured to take the structure of each cluster as an input respectively, and calculate the cluster energy of each cluster and the respective sub - item energies that make up the cluster energy by using quantum chemical methods;

[0210] The third calculation unit is configured to take each shell structure as an input respectively, and calculate the shell energy of each shell structure and the respective sub - item energies that make up the shell energy by using quantum chemical methods.

[0211] Optionally, the quantum chemical method may include the tight - binding DFTB method based on density functional theory, and its energy calculation formula may be: E 能量 = E 0近似 + E scc + E rep + E nuc + E disp_corr ;

[0212] Among them, the respective sub - item energies E 0近似 , E scc , E rep , E nuc , E disp_corr are respectively: the orbital energy under zero - order approximation, the second / third - order electrostatic energy, the short - range repulsive energy of valence bonds, the nuclear repulsive energy, and the long - range dispersion correction energy.

[0213] Optionally, the quantum chemical method may include the density functional theory (DFT) method, and its energy calculation formula may be: E 能量 = E0 + E j + E x + E c + E nuc + E disp_corr ;

[0214] Among them, the respective sub - item energies E0, E j , E x , E c , E nuc , E disp_corr are respectively: the orbital energy, the electron electrostatic energy, the exchange energy, the correlation energy, the nuclear repulsive energy, and the long - range dispersion correction energy.

[0215] Optionally, the second calculation module 630 may further include:

[0216] A fourth calculation unit, configured to calculate, according to each sub-item energy of the molecular energy, each sub-item energy of each cluster energy, and each sub-item energy of each shell energy, each sub-item energy of the interaction energy between the central molecule and each shell structure by using a first preset formula;

[0217] A fifth calculation unit, configured to calculate, according to each sub-item energy of the interaction energy between the central molecule and each shell structure, each sub-item energy of the lattice energy of the target crystal structure by using a second preset formula;

[0218] A sixth calculation unit, configured to calculate the lattice energy of the target crystal structure by using a third preset formula according to each sub-item energy of the lattice energy and the contribution coefficient of each sub-item energy.

[0219] Optionally, the first preset formula may be: E 壳n相互作用能,i = E 团簇n,i – E 分子,i – E 壳n,i ;

[0220] where n is the cluster number, the value of n ranges from 1 to M, i is the number of each sub-item energy, E 团簇n,i is the i-th sub-item energy of the cluster energy of the n-th cluster, E 分子,i is the i-th sub-item energy of the molecular energy of the central molecule, E 壳n,i is the i-th sub-item energy of the shell energy of the n-th shell structure, and E 壳n相互作用能,i is the i-th sub-item energy of the interaction energy between the central molecule and the n-th shell structure.

[0221] Optionally, when M is greater than or equal to 3, the second preset formula may be:

[0222] E 壳n相互作用能.i = E 晶格,i + A * (R n ) -B ;

[0223] where E 晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, R n is the truncation radius adopted when constructing the n-th cluster, and A and B are two different attenuation coefficients;

[0224] At this time, the fifth calculation unit may specifically be configured to calculate each sub-item energy of the interaction energy between the central molecule and each shell structure by using the second preset formula to obtain multiple groups of E 晶格,i , A, and B; fit the multiple groups of E 晶格,i , A, and B to obtain each sub-item energy of the lattice energy of the target crystal structure.

[0225] Optionally, when M is 2, the second preset formula can be:

[0226] E 晶格，i = [E 壳1相互作用能,i (R1) 3 - E 壳2相互作用能,i (R2) 3 / [(R1) 3 -(R2) 3 ;

[0227] Wherein, E 晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, E 壳1相互作用能,i is the i-th sub-item energy of the interaction energy between the central molecule and the first shell structure, E 壳2相互作用能,i is the i-th sub-item energy of the interaction energy between the central molecule and the second shell structure, R1 is the truncation radius used when constructing the first cluster, and R2 is the truncation radius used when constructing the second cluster.

[0228] Optionally, when M is 1 and n is 1, the second preset formula can be: E 晶格,i = E 壳1相互作用能,i ;

[0229] Wherein, E 晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, and E 壳1相互作用能,i is the i-th sub-item energy of the interaction energy between the central molecule and the shell structure.

[0230] Optionally, the third preset formula can be: E 晶格 = sum(k i E 晶格,i );

[0231] Wherein, E 晶格 is the lattice energy of the target crystal structure, E 晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, and k i is the contribution coefficient of the i-th sub-item energy of the lattice energy.

[0232] Optionally, the calculation method of the contribution coefficients of the sub-item energies of the lattice energy can include: obtaining a plurality of reference crystal structures and the reference lattice energies of each reference crystal structure; respectively calculating the sub-item energies of the lattice energy of each reference crystal structure; setting the contribution coefficients of the sub-item energies of the lattice energy; according to the sub-item energies of the lattice energy of each reference crystal structure and the set contribution coefficients, obtaining the sub-item energies of the predicted lattice energy of each reference crystal structure; using the sub-item energies of the reference lattice energy and the sub-item energies of the predicted lattice energy of each reference crystal structure to fit the set contribution coefficients to obtain the contribution coefficients of the sub-item energies after fitting.

[0233] Optionally, the third calculation module 640 may further include:

[0234] A correction unit for performing energy correction on the molecular energy to obtain the corrected molecular energy;

[0235] A seventh calculation unit for calculating the total crystal energy of the target crystal structure by using the corrected molecular energy and the lattice energy.

[0236] In the device according to the embodiment of the present application, by calculating the energy of the central molecule (nucleus) and the cluster (shell), a "nucleus-shell" calculation scheme is established, which can avoid the calculation of a large number of many-body clusters such as two-body and three-body in the prior art, and can obtain higher energy accuracy than directly using a low-precision calculation method in the original, and the calculation efficiency is also greatly improved.

[0237] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment related to the method, and will not be elaborated here.

[0238] The embodiment of the present application further provides a molecular crystal energy comparison device, which can be used to execute the molecular crystal energy comparison method provided in the foregoing embodiment. Specifically, the device may include:

[0239] An acquisition module for acquiring at least two crystal structures to be compared;

[0240] A calculation module for calculating the total crystal energy of each crystal structure by using the molecular crystal energy calculation device provided in the foregoing embodiment for each crystal structure;

[0241] A determination module for determining the crystal energy magnitude relationship of the at least two crystal structures according to the total crystal energy of each crystal structure.

[0242] The embodiment of the present application further provides an electronic device, which can be used to execute the molecular crystal energy calculation method and / or the molecular crystal energy comparison method provided in the foregoing embodiment. As Figure 7 shown, the electronic device 700 includes a memory 710 and a processor 720.

[0243] The processor 720 can be a Central Processing Unit (CPU), or it can be other general-purpose processors, Digital Signal Processors (DSPs), Application Specific Integrated Circuits (ASICs), Field-Programmable Gate Arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc. The general-purpose processor can be a microprocessor or any conventional processor, etc.

[0244] The memory 710 can include various types of storage units, such as system memory, read-only memory (ROM), and permanent storage devices. Among them, the ROM can store static data or instructions required by the processor 720 or other modules of the computer. The permanent storage device can be a readable and writable storage device. The permanent storage device can be a non-volatile storage device that does not lose the stored instructions and data even when the computer is powered off. In some embodiments, the permanent storage device uses a mass storage device (such as a magnetic or optical disk, flash memory) as the permanent storage device. In some other embodiments, the permanent storage device can be a removable storage device (such as a floppy disk, optical drive). The system memory can be a readable and writable storage device or a volatile readable and writable storage device, such as dynamic random access memory. The system memory can store some or all of the instructions and data required by the processor during operation. In addition, the memory 710 can include any combination of computer-readable storage media, including various types of semiconductor storage chips (such as DRAM, SRAM, SDRAM, flash memory, programmable read-only memory), and magnetic disks and / or optical disks can also be used. In some embodiments, the memory 710 can include a removable storage device that is readable and / or writable, such as a compact disc (CD), read-only digital versatile disc (such as DVD-ROM, dual-layer DVD-ROM), read-only Blu-ray disc, super density disc, flash memory card (such as SD card, min SD card, Micro-SD card, etc.), magnetic floppy disk, etc. Computer-readable storage media do not include carrier waves and instantaneous electronic signals transmitted wirelessly or by wire.

[0245] An executable code is stored on the memory 710. When the executable code is processed by the processor 720, it can cause the processor 720 to execute some or all of the methods described above.

[0246] In addition, the method according to the present application can also be implemented as a computer program or a computer program product, which includes computer program code instructions for performing some or all of the steps in the above method of the present application.

[0247] Alternatively, the present application can also be implemented as a computer-readable storage medium (or a non-transitory machine-readable storage medium or a machine-readable storage medium), on which executable code (or a computer program or computer instruction code) is stored. When the executable code (or the computer program or computer instruction code) is executed by a processor of an electronic device (or a server, etc.), the processor is caused to execute some or all of the steps of the above method according to the present application.

[0248] The various embodiments of the present application have been described above. The above description is exemplary and not exhaustive, and is also not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, the practical application or the improvement of the technology in the market, or to enable other ordinary skill in the art in the technical field to understand the disclosed embodiments.

Claims

1. A method for calculating the energy of a molecular crystal, characterized in that, Including: Obtain a target crystal structure, and determine a central molecule, M clusters, and M shell structures from the target crystal structure, where M is an integer greater than or equal to 1; Use quantum chemical methods to calculate the molecular energy of the central molecule, the cluster energy of each cluster, and the shell energy of each shell structure respectively; Calculate the lattice energy of the target crystal structure based on the molecular energy, the cluster energy, and the shell energy; Calculate the total crystal energy of the target crystal structure based on the molecular energy and the lattice energy; Among them, the determining the central molecule, M clusters, and M shell structures from the target crystal structure includes: Select a molecule from the target crystal structure as the central molecule; Taking the geometric center of the central molecule as the center of the sphere, and using M different preset radii as truncation radii to perform atomic truncation on the target crystal structure respectively, and select the molecules with atoms within the truncation radius to construct clusters, obtaining M clusters; Delete the central molecule from each cluster to obtain the corresponding M shell structures.

2. The method according to claim 1, characterized in that, The selecting the molecules with atoms within the truncation radius to construct clusters includes: Select the molecules with all atoms within the truncation radius to construct clusters; or, If there are molecules with only some atoms within the truncation radius, perform a complementation process on the molecules, and use the complemented molecules and the molecules with all atoms within the truncation radius to construct clusters.

3. The method according to claim 1, characterized in that, The using quantum chemical methods to calculate the molecular energy of the central molecule, the cluster energy of each cluster, and the shell energy of each shell structure respectively includes: Taking the molecular structure of the central molecule as the input, and using quantum chemical methods to calculate the molecular energy of the central molecule and the sub - item energies that make up the molecular energy; Taking the structure of each cluster as the input respectively, and using the quantum chemical methods to calculate the cluster energy of each cluster and the sub - item energies that make up the cluster energy; Taking each shell structure as the input respectively, and using the quantum chemical methods to calculate the shell energy of each shell structure and the sub - item energies that make up the shell energy.

4. The method according to claim 3, wherein The quantum chemical method includes the tight - binding DFTB method based on density functional theory, and the energy calculation formula is: E 能量 = E 0近似 + E scc + E rep + E nuc + E disp_corr ; Among them, the respective sub-item energies E 0近似 , E scc , E rep , E nuc , E disp_corr are respectively: the orbital energy under zero-order approximation, the second / third-order electrostatic energy, the short-range repulsive energy of valence bonds, the nuclear repulsive energy, and the long-range dispersion correction energy.

5. The method according to claim 3, characterized in that The quantum chemical method includes the density functional theory DFT method, and the energy calculation formula is: E 能量 = E0 + E j + E x + E c + E nuc + E disp_corr ; Among them, the partial energies E0, E j , E x , E c , E nuc , E disp_corr are respectively: orbital energy, electronic electrostatic energy, exchange energy, correlation energy, nuclear repulsion energy, long-range dispersion correction energy.

6. The method according to claim 3, wherein The calculating the lattice energy of the target crystal structure based on the molecular energy, the cluster energy, and the shell energy includes: Based on the sub - item energies of the molecular energy, the sub - item energies of the cluster energy of each cluster, and the sub - item energies of the shell energy of each shell structure, use the first preset formula to calculate the sub - item energies of the interaction energy between the central molecule and each shell structure; Based on the sub - item energies of the interaction energy between the central molecule and each shell structure, use the second preset formula to calculate the sub - item energies of the lattice energy of the target crystal structure; The lattice energy of the target crystal structure is calculated by using a third preset formula according to the partial energies of the lattice energy and the contribution coefficients of the partial energies.

7. The method according to claim 6, wherein The first preset formula is: E 壳n相互作用能,i = E 团簇n,i – E 分子,i – E 壳n,i ; Wherein, n is the cluster number, the value of n ranges from 1 to M, i is the number of each sub - item energy, and E 团簇n,i is the i - th sub - item energy of the cluster energy of the n - th cluster, and E 分子,i is the i - th sub - item energy of the molecular energy of the central molecule, and E 壳n,i is the i - th sub - item energy of the shell energy of the n - th shell structure, and E 壳n相互作用能,i is the i - th sub - item energy of the interaction energy between the central molecule and the n - th shell structure.

8. The method according to claim 7, wherein When M is greater than or equal to 3, the second preset formula is: E 壳n相互作用能.i = E 晶格,i + A*(Rn) -B ; Among them, the E晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, the Rn is the truncation radius used when constructing the n-th cluster, and the A and the B are two different attenuation coefficients; Calculating the partial energies of the lattice energy of the target crystal structure by using the second preset formula according to the partial energies of the interaction energy between the central molecule and each of the shell structures includes: The respective sub - energies of the interaction energy between the central molecule and each of the shell structures are calculated using the second preset formula to obtain multiple sets of the E 晶格,i , A, and B; For multiple sets of the said E 晶格,i , A, and B are fitted to obtain the respective energies of the lattice energy of the said target crystal structure.

9. The method according to claim 7, wherein When M is 2, the second preset formula is: E 晶格，i = [E 壳1相互作用能,i (R1) 3 - E 壳2相互作用能,i (R2) 3 / [(R1) 3 - (R2) 3 ; wherein, the E 晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, and the E 壳1相互作用能,i is the i-th sub-item energy of the interaction energy between the central molecule and the first shell structure, and the E 壳2相互作用能,i is the i-th sub-item energy of the interaction energy between the central molecule and the second shell structure, R1 is the truncation radius used when constructing the first cluster, and R2 is the truncation radius used when constructing the second cluster.

10. The method according to claim 7, wherein When M is 1 and n is 1, the second preset formula is: E 晶格,i = E 壳1相互作用能,i ; Among them, the E 晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, and the E 壳1相互作用能,i is the i-th sub-item energy of the interaction energy between the central molecule and the shell structure.

11. The method according to claim 6, wherein The third preset formula is: E 晶格 = sum(k i E 晶格,i ); Among them, the E 晶格 is the lattice energy of the target crystal structure, and the E 晶格,i is the i-th sub-item energy of the lattice energy of the target crystal structure, and the k i is the contribution coefficient of the i-th sub-item energy of the lattice energy.

12. The method according to claim 6, characterized in that, The calculation method of the contribution coefficients of the partial energies of the lattice energy includes: Obtaining a plurality of reference crystal structures and the reference lattice energy of each of the reference crystal structures; Calculating the partial energies of the lattice energy of each of the reference crystal structures respectively; setting the contribution coefficients of the partial energies of the lattice energy; Obtaining the partial energies of the predicted lattice energy of each of the reference crystal structures according to the partial energies of the lattice energy of each of the reference crystal structures and the set contribution coefficients; Fitting the set contribution coefficients by using the partial energies of the reference lattice energy and the partial energies of the predicted lattice energy of each of the reference crystal structures to obtain the contribution coefficients of the partial energies after fitting.

13. The method according to any one of claims 1-12, characterized in that, Calculating the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy includes: Performing energy correction on the molecular energy to obtain the corrected molecular energy; Calculating the total crystal energy of the target crystal structure by using the corrected molecular energy and the lattice energy.

14. A method for comparing the energies of molecular crystals, characterized in that, Including: Obtaining at least two crystal structures to be compared; Calculating the total crystal energy of each of the crystal structures by using the method according to any one of claims 1-13 to obtain the total crystal energy of each of the crystal structures; Determining the magnitude relationship of the crystal energies of the at least two crystal structures according to the total crystal energy of each of the crystal structures.

15. A molecular crystal energy calculation device, characterized in that, Including: An acquisition module, configured to acquire a target crystal structure, and determine a central molecule, M clusters, and M shell structures from the target crystal structure, where M is an integer greater than or equal to 1; A first calculation module, configured to calculate the molecular energy of the central molecule, the cluster energy of each of the clusters, and the shell energy of each of the shell structures respectively by using a quantum chemistry method; A second calculation module, configured to calculate the lattice energy of the target crystal structure according to the molecular energy, the cluster energy, and the shell energy; A third calculation module, configured to calculate the total crystal energy of the target crystal structure according to the molecular energy and the lattice energy; Among them, the obtaining module determines the central molecule, M clusters, and M shell structures from the target crystal structure, including: selecting a molecule from the target crystal structure as the central molecule; using the geometric center of the central molecule as the center of the sphere, and using M different preset radii as truncation radii to perform atomic truncation on the target crystal structure respectively, selecting the molecules with atoms within the truncation radius to construct clusters, and obtaining M clusters; deleting the central molecule from each of the clusters to obtain the corresponding M shell structures.

16. A molecular crystal energy comparison device, characterized in that, including: an obtaining module, configured to obtain at least two crystal structures to be compared; a calculation module, configured to perform crystal energy calculation on each of the crystal structures by using the method according to any one of claims 1-13, to obtain the total crystal energy of each of the crystal structures; a determination module, configured to determine the crystal energy magnitude relationship of the at least two crystal structures according to the total crystal energy of each of the crystal structures.

17. An electronic device, characterized in that, including: a processor; and a memory, storing executable code thereon, when the executable code is executed by the processor, causing the processor to execute the method according to any one of claims 1-14.

18. A computer-readable storage medium, storing executable code thereon, when the executable code is executed by a processor of an electronic device, causing the processor to execute the method according to any one of claims 1-14.

Images