Charge density high-flux calculation and analysis method and device in solid interface friction process

Abstract

The invention discloses a charge density high-flux calculation and analysis method and device in a solid interface friction process, and relates to the technical field of material high-flux calculation, and the method comprises the steps: carrying out the automatic modeling based on modeling data, and obtaining a modeled file; creating an automatic submission folder based on the modeled file, and moving the modeled file to the automatic submission folder to complete an automatic submission task; according to the automatic submission folder, determining configuration energy and charge density of an interface center position; and fitting the configuration energy and the charge density at the center position of the interface, and outputting the charge density in the isobaric friction process. According to the method, automatic modeling, automatic calculation submitting, automatic system energy and charge density outputting, automatic data fitting and charge density outputting in the isobaric friction process are achieved, and the labor time consumed in the operation process for calculating charge density evolution in the friction process of the solid interface system is greatly saved.

Description

Technical Field

[0001] This application relates to the technical field of high-throughput material calculation, and particularly to a high-throughput calculation and analysis method and device for charge density during the solid interface friction process. Background Art

[0002] In the broad fields of materials science and solid-state physics, a deep understanding of the charge density at solid interfaces is of inestimable value for driving technological innovation and materials design. Charge density, as the core of the microscopic properties of materials, determines a series of key characteristics such as the electrical conductivity, optical properties, thermal properties, and chemical reactivity of materials. Especially at solid interfaces, due to significant changes in atomic arrangement, electron cloud distribution, and interaction modes, charge density exhibits more complex and rich behavior patterns, which are directly related to macroscopic physical and chemical phenomena such as interfacial chemical bonding, adhesion strength, and friction and wear. Charge density calculation and analysis, especially first-principles calculations based on quantum mechanics principles, have become indispensable tools for analyzing the microscopic mechanisms of solid interfaces. Such calculations can not only accurately predict the band structure, density of states distribution, charge transfer situation, etc. at the interface, but also reveal the essence of atomic interactions, such as the formation and strength of covalent bonds, ionic bonds, metallic bonds, and van der Waals forces. The acquisition of this information is of great significance for designing high-performance interfacial materials, optimizing interfacial structures to improve material stability, and regulating interfacial reaction kinetics.

[0003] In the field of tribology, the interfacial charge density, especially the interfacial charge density, plays a central role. The energy dissipation, wear mechanism, and lubrication effect during the friction process are all closely related to the dynamic changes of the interfacial electron cloud. Through high-throughput calculation methods, the interaction between interfaces under different conditions can be simulated, the changing trend of the friction coefficient can be predicted, and thus the development of low-friction and high-wear-resistant materials and the optimization design of lubricants can be guided. However, when using first-principles to study the evolution of interfacial charge density during the friction process, the construction of the calculation model and the post-processing of data take up a large amount of time and energy of researchers. For example, to comprehensively calculate the charge density during the friction process of an interfacial system, usually about 1000 models need to be established (the upper half of the interface moves 6, 6, and 30 steps in the x, y, and z directions respectively), and then other input files required by the first-principles calculation software need to be prepared and submitted to the first-principles calculation software for calculation one by one. Then, the charge density of each model is manually exported and analyzed to output the charge density distribution at different interfacial distances. If the charge density distribution under the equal-load friction condition needs to be calculated, the relationship between the model energy and the interfacial distance also needs to be fitted, the interfacial distance under a given load needs to be solved, the relationship between the interfacial charge density and the distance needs to be fitted, and finally the charge density under a specific load is given. Now let's simply estimate the time consumed by a skilled researcher in the above process. It takes about 500 - 1000 minutes (1 minute per model) to build the model, 500 - 1000 minutes (1 minute per model) to prepare and submit other input files required by the DFT software, 250 - 500 minutes (0.5 minute per model) to manually search and output the calculation results, and 500 - 1000 minutes for data post-processing. Using the DFT method to completely study the evolution of the charge density during the friction process of an interfacial system takes about 58 hours (about 7 working days) in the operation process. In addition, for each additional system studied, the time consumed doubles. Since these operations are usually just simple repetitions, this time is of little significance for improving scientific research capabilities.

[0004] In view of this, there is an urgent need for a set of automated and high-throughput calculation solutions for the charge density during the friction process of solid interfaces. Summary of the Invention

[0005] The purpose of this application is to provide a high-throughput calculation and analysis method and device for the charge density during the friction process of solid interfaces, which can greatly save the time for researchers to study the evolution of the charge density of the interfacial system.

[0006] To achieve the above purpose, this application provides the following solutions:

[0007] In the first aspect, this application provides a high-throughput calculation and analysis method for the charge density during the friction process of solid interfaces. The high-throughput calculation and analysis method for the charge density during the friction process of solid interfaces includes:

[0008] Based on the modeling data, automatic modeling is performed to obtain the modeled file; the modeling data includes: a POSCAR file, the number of moving steps of the upper part of the interface in the x, y, and z directions, and the distance of each moving step in the z direction; the POSCAR file is an interface configuration file used to specify the size of the interface and the position of each atom.

[0009] Based on the modeled file, an automatic submission folder is created, and the modeled file is moved to the automatic submission folder to complete the automatic submission task.

[0010] According to the automatic submission folder, the configuration energy and the charge density at the interface center position are determined.

[0011] The configuration energy and the charge density at the interface center position are fitted to output the charge density during the equal-load friction process.

[0012] Optionally, based on the modeling data, automatic modeling is performed to obtain the modeled file, specifically including:

[0013] Obtain the modeling data.

[0014] Calculate the lengths of the minimum periods of the interface in the x and y directions, and calculate the lengths corresponding to each moving step in the x and y directions according to the given number of steps.

[0015] According to the lengths corresponding to each moving step in the x, y, and z directions and the total number of steps, the upper part of the interface in the POSCAR file is moved sequentially, the POSCAR file after each move is constructed and output, and renamed as POSCAR_i_j_k to obtain the modeled file.

[0016] Optionally, based on the modeled file, an automatic submission folder is created, and the modeled file is moved to the automatic submission folder to complete the automatic submission task, specifically including:

[0017] Obtain the INCAR file, KPOINTS file, POTCAR file, and all POSCAR_i_j_k files; the INCAR file is the basic setting parameters of the first-principles software VASP (Vienna Ab initio Simulation Package); the KPOINTS file is the K-point setting; the POTCAR file is the potential function of each type of atom at the interface; the POSCAR_i_j_k file is the modeled file.

[0018] For each POSCAR_i_j_k file, create an automatic submission folder i_j_k, and move the POSCAR_i_j_k file, INCAR file, KPOINTS file, and POTCAR file to the automatic submission folder i_j_k.

[0019] Automatically traverse all the automatic submission folders and submit the calculation tasks.

[0020] Optionally, the determination of the configuration energy specifically includes:

[0021] Automatically traverse all the automatic submission folders, and read the configuration energy from the OUTCAR file in each folder; the OUTCAR file is the output file of the first-principles software VASP, which contains the optimized system energy.

[0022] Automatically save the configuration energy into fEnergy[i][j][k]; fEnergy[i][j][k] is a three-dimensional array used to save the energy of each modeled file.

[0023] Optionally, the determination of the charge density at the interface center position specifically includes:

[0024] Automatically traverse all the automatic submission folders, and determine the center position of the interface in each configuration from the CONTCAR file in each folder; the CONTCAR file is the atomic position file of the optimized system.

[0025] Automatically traverse all the automatic submission folders, integrate the CHGCAR file in the x and y directions for each folder, calculate the charge density at the center position of the interface in each configuration, and save the charge density at the center position of the interface in each configuration into fCHGCAR_InterfaceCenter[i][j][k]; the CHGCAR file is the charge density file of the system; fCHGCAR_InterfaceCenter[i][j][k] is a three-dimensional array used to save the charge density at the interface center position of each modeled file.

[0026] Optionally, the calculation formula for the charge density at the interface center position is:

[0027]

[0028] Among them, is the charge density at the interface center position; ρ(x, y, z, i, j, k) is the three-dimensional charge density saved in the CHGCAR file.

[0029] Optionally, fit the configurational energy and the charge density at the interface center position to output the charge density during the equal-load friction process, specifically including:

[0030] Fit the functional relationship between the data in fEnergy[i][j][k] and the interface distance to obtain the adhesion energy corresponding to any interface distance.

[0031] Based on the data in fEnergy[i][j][k] and the interface distance, establish a quantitative relationship between the load corresponding to the interface distance of the configuration and the interface distance.

[0032] Based on the relationship between any interface distance and the adhesion energy and the quantitative relationship between the load and the interface distance, calculate the adhesion energy corresponding to any load and the load work term, and sum them to obtain the total energy of the configuration during the equal-load friction process.

[0033] Fit the functional relationship between the data in fCHGCAR_InterfaceCenter[i][j][k] and the interface distance.

[0034] Based on the quantitative relationship between the load and the interface distance and the relationship between the interface distance and the charge density at the interface center, obtain the charge density at the interface center of all configurations during the equal-load friction process.

[0035] Optionally, the expression of the quantitative relationship between the load corresponding to the interface distance of the configuration and the interface distance is:

[0036]

[0037] where f ext (i,j,h) is the load corresponding to the (i,j) configuration at the interface distance of h, E(i,j,h) is the adhesion energy at any interface distance, and h is the interface distance.

[0038] Optionally, the calculation formula for the total energy of the configuration during the equal-load friction process is:

[0039] E(i,j,f ext ) = E(i,j,h(i,j,f ext )) + f ext * h(i,j,f ext );

[0040] where E(i,j,f ext ) is the total energy of the configuration during the equal-load friction process, E(i,j,h(i,j,f ext )) is the adhesion energy corresponding to any load, and f ext * h(i,j,f ext ) is the load work corresponding to any load.

[0041] In a second aspect, the present application provides an apparatus for high-throughput calculation and analysis of charge density during solid interface friction. The apparatus for high-throughput calculation and analysis of charge density during solid interface friction includes:

[0042] An automatic modeling unit, configured to perform automatic modeling based on modeling data to obtain a modeled file. The modeling data includes: a POSCAR file, the number of movement steps of the upper part of the interface in the x, y, and z directions, and the distance of each movement step in the z direction. The POSCAR file is an interface configuration file for specifying the size of the interface and the position of each atom.

[0043] An automatic submission unit, configured to create an automatic submission folder based on the modeled file, and move the modeled file to the automatic submission folder to complete the automatic submission task.

[0044] A configuration energy and charge density determination unit at the interface center position, configured to determine the configuration energy and the charge density at the interface center position according to the automatic submission folder.

[0045] A fitting unit, configured to fit the configuration energy and the charge density at the interface center position, and output the charge density during the equal-load friction process.

[0046] According to the specific embodiments provided by the present application, the following technical effects are disclosed:

[0047] The present application provides a method and device for high-throughput calculation and analysis of charge density during the solid interface friction process. The method includes: based on modeling data, performing automatic modeling to obtain a modeled file; the modeling data includes: a POSCAR file, the number of movement steps of the upper part of the interface in the x, y, and z directions, and the distance of each movement step in the z direction; the POSCAR file is an interface configuration file used to specify the size of the interface and the position of each atom; based on the modeled file, creating an automatic submission folder, and moving the modeled file to the automatic submission folder to complete the automatic submission task; according to the automatic submission folder, determining the configuration energy and the charge density at the interface center position; fitting the configuration energy and the charge density at the interface center position, and outputting the charge density during the isocharge friction process. Compared with the prior art in which the charge density evolution during the solid interface friction process is calculated manually, the high-throughput calculation method proposed in the present application realizes automatic modeling, automatic submission of calculations, automatic output of the system energy and charge density, automatic fitting of data, and output of the charge density during the isocharge friction process, greatly saving the manual time consumed in the operation process of calculating the charge density evolution of the solid interface system (about 7 working days for one system, and the time consumed doubles for each additional system studied), which allows researchers to invest their limited time and energy in more creative matters. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0049] Figure 1 It is an application environment diagram of a method for high-throughput calculation and analysis of charge density during the solid interface friction process in an embodiment of the present application.

[0050] Figure 2 It is a flowchart of a method for high-throughput calculation and analysis of charge density during the solid interface friction process provided in an embodiment of the present application.

[0051] Figure 3 It is a high-throughput calculation flowchart of the charge density during the solid interface friction process provided in an embodiment of the present application.

[0052] Figure 4 It is a schematic diagram of the Gr / Gr configuration and typical configurations during the friction process provided in an embodiment of the present application.

[0053] Figure 5Schematic diagram of the equidistant friction potential energy surface of the Gr / Gr interface provided by an embodiment of the present application.

[0054] Figure 6 Schematic diagram of the relationship between the total energy of the system and the interface distance, and the relationship between the shear strength and the interface distance during the friction process of the Gr / Gr interface provided by an embodiment of the present application.

[0055] Figure 7 Schematic diagram of the method for defining the interfacial center charge density provided by an embodiment of the present application.

[0056] Figure 8 Schematic diagram of the relationship between the interfacial center charge density and the interface distance, and the relationship between the shear strength and the interfacial center charge density difference during the friction process of the Gr / Gr interface provided by an embodiment of the present application.

[0057] Figure 9 Schematic diagram of the equicharge friction potential energy surface of the Gr / Gr interface provided by an embodiment of the present application.

[0058] Figure 10 Schematic diagram of the relationship between the total energy of the system and the load, and the relationship between the shear strength and the load during the friction process of the Gr / Gr interface provided by an embodiment of the present application.

[0059] Figure 11 Schematic diagram of the relationship between the interfacial center charge density and the load, and the relationship between the shear strength and the interfacial center charge density difference during the friction process of the Gr / Gr interface provided by an embodiment of the present application.

[0060] Figure 12 Schematic diagram of the functional modules of a device for high-throughput calculation and analysis of charge density during the friction process of a solid interface provided by an embodiment of the present application.

[0061] Figure 13 Schematic diagram of the structure of a computer device provided by an embodiment of the present application. Detailed implementation manners

[0062] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.

[0063] To make the above objects, features, and advantages of the present application more obvious and understandable, the present application will be further described in detail below in conjunction with the accompanying drawings and specific implementation manners.

[0064] The high-throughput calculation and analysis method of charge density during the solid interface friction provided by the embodiments of the present application can be applied to, for example, Figure 1 the application environment shown. Among them, the terminal 102 communicates with the server 104 through the network. The data storage system can store the data that the server 104 needs to process. The data storage system can be set separately, integrated on the server 104, placed on the cloud or other servers. The terminal 102 can send the modeling data to the server 104. The modeling data includes: the POSCAR file, the number of movement steps of the upper part of the interface in the x, y, and z directions, and the distance of each movement step in the z direction; the POSCAR file is an interface configuration file used to specify the size of the interface and the position of each atom; after receiving the modeling data, the server 104 performs automatic modeling based on the modeling data to obtain the modeled file; based on the modeled file, an automatic submission folder is created, and the modeled file is moved to the automatic submission folder to complete the automatic submission task; according to the automatic submission folder, the configuration energy and the charge density at the interface center position are determined; the configuration energy and the charge density at the interface center position are fitted to output the charge density during the equal-load friction process. The server 104 can feedback the obtained charge density during the equal-load friction process to the terminal 102. In addition, in some embodiments, the high-throughput calculation and analysis method of charge density during the solid interface friction can also be implemented by the server 104 or the terminal 102 alone. For example, the terminal 102 can directly perform the high-throughput calculation and analysis of the charge density during the solid interface friction on the modeling data, or the server 104 can obtain the modeling data from the data storage system and perform the high-throughput calculation and analysis of the charge density during the solid interface friction on the modeling data.

[0065] Among them, the terminal 102 can be, but is not limited to, various desktop computers, laptop computers, smart phones, and tablet computers. The server 104 can be implemented by an independent server or a server cluster composed of multiple servers, and can also be a cloud server.

[0066] In an exemplary embodiment, as Figure 2 and Figure 3 shown, a high-throughput calculation and analysis method of charge density during the solid interface friction is provided. This method is executed by a computer device, and can be specifically executed by a computer device such as a terminal or a server alone, or jointly executed by a terminal and a server. In the embodiments of the present application, taking this method applied to Figure 1 the server 104 in as an example for illustration, it includes the following steps S1 to S4. Among them:

[0067] S1: Based on the modeling data, automatic modeling is performed to obtain a modeled file; the modeling data includes: a POSCAR file, the number of movement steps of the interface part in the x, y, and z directions, and the distance of each movement step in the z direction; the POSCAR file is an interface configuration file, which is used to specify the size of the interface and the position of each atom.

[0068] S2: Based on the modeled file, an automatic submission folder is created, and the modeled file is moved to the automatic submission folder to complete the automatic submission task.

[0069] S3: According to the automatic submission folder, the configuration energy and the charge density at the center of the interface are determined.

[0070] S4: Fitting the configuration energy and the charge density at the center of the interface, and outputting the charge density during the equal-load friction process.

[0071] The implementation of the above-mentioned steps S1 to S4 realizes automatic modeling, automatic submission of calculations, automatic output of system energy and charge density, automatic data fitting and output of results during equal-load friction, thereby greatly saving the time of scientific researchers in studying the evolution of charge density during the friction process of the interface system.

[0072] As an optional implementation, in step S1, it specifically includes:

[0073] S11: Obtain modeling data.

[0074] S12: Calculate the length of the minimum period of the interface in the x and y directions, and calculate the length corresponding to each moving step in the x and y directions according to the given number of steps.

[0075] S13: According to the length corresponding to each moving step in the x, y, and z directions and the total number of steps, the upper part of the interface in the POSCAR file is moved in sequence, and the POSCAR file after each movement is constructed and output, and renamed as POSCAR_i_j_k to obtain the modeled file.

[0076] Specifically, for automatic modeling: The program reads the given POSCAR file (interface configuration file, specifying the size of the interface and the position of each atom), the number of movement steps of the upper part of the interface in the x, y, and z directions, and the distance of each movement step in the z direction, calculates the lengths of the minimum periods in the x and y directions, and calculates the lengths corresponding to each movement step in the x and y directions according to the given number of steps; According to the lengths corresponding to each movement step in the x, y, and z directions and the total number of steps, the upper half of the interface in the POSCAR file is moved successively, the POSCAR file after each movement is constructed and output, and it is renamed as POSCAR_i_j_k, where i, j, and k are the number of steps of the upper half of the interface moving in the x, y, and z directions respectively. A typical POSCAR_i_j_k configuration is as Figure 4 shown.

[0077] As an alternative implementation, in step S2, it specifically includes:

[0078] S21: Obtain the INCAR file, KPOINTS file, POTCAR file, and all POSCAR_i_j_k files; the INCAR file is the basic setting parameters of the first-principles software VASP; the KPOINTS file is the K-point setting; the POTCAR file is the potential function of each type of atom on the interface; the POSCAR_i_j_k file is the file after modeling.

[0079] S22: For each POSCAR_i_j_k file, create an automatic submission folder i_j_k, and move the POSCAR_i_j_k file, INCAR file, KPOINTS file, and POTCAR file to the automatic submission folder i_j_k.

[0080] S23: Automatically traverse all automatic submission folders and submit calculation tasks.

[0081] Specifically, for automatic submission of calculations: The program reads the given INCAR file, KPOINTS file, POTCAR file, and POSCAR_i_j_k file. For each POSCAR_i_j_k file, a folder named i_j_k is created, and the INCAR file, KPOINTS file, POTCAR file, and POSCAR_i_j_k file are automatically copied to the i_j_k folder, and POSCAR_i_j_k is renamed as POSCAR. Then, it enters the i_j_k folder in sequence and automatically submits tasks. Among them, the INCAR file, KPOINTS file, and POTCAR file are input files required by the first-principles software VASP; the INCAR specifies the basic setting parameters of VASP; the KPOINTS specifies the K-point settings; the POTCAR is the potential function of various types of atoms on the interface. It should be noted that: Automatically submitting tasks will automatically call the commercial first-principles calculation software VASP to calculate the total energy and electronic structure of the calculation configuration.

[0082] As an alternative implementation, in step S3, the determination of the configuration energy specifically includes:

[0083] A1: Automatically traverse all automatically submitted folders, and read the configuration energy from the OUTCAR file in each folder; the OUTCAR file is the output file of the first-principles software VASP, which contains the optimized system energy.

[0084] A2: Automatically save the configuration energy into fEnergy[i][j][k]; fEnergy[i][j][k] is a three-dimensional array used to save the energy of each modeled file.

[0085] The determination of the charge density at the center position of the interface specifically includes:

[0086] B1: Automatically traverse all automatically submitted folders, and determine the center position of the interface in each configuration from the CONTCAR file in each folder; the CONTCAR file is the atomic position file of the optimized system.

[0087] B2: Automatically traverse all automatically submitted folders, integrate the CHGCAR file in the x and y directions for each folder, calculate the charge density at the center position of the interface in each configuration, and save the charge density at the center position of the interface in each configuration into fCHGCAR_InterfaceCenter[i][j][k]; the CHGCAR file is the charge density file of the system; fCHGCAR_InterfaceCenter[i][j][k] is a three-dimensional array used to save the charge density at the center position of the interface of each modeled file.

[0088] Specifically, the system energy and charge density are automatically output: after the program detects that all calculation tasks are completed, it enters the i_j_k folder in turn, reads the configuration energy in the OUTCAR file, and saves the read configuration energy to the three-dimensional array of fEnergy[i][j][k]. At this point, the potential energy surface corresponding to the given interface distance can be output, such as Figure 5 As shown, the interface distances corresponding to (a), (b), and (c) are Shear Strength Among them, E(i 2 ,j 2 ,k) and E(i 1 ,j 1 , k) are the total energies corresponding to the saddle point configuration and the energy minimum point configuration obtained from the friction potential energy surface, l is the distance from the saddle point to the energy minimum point, and A is the area of ​​the interface system. Based on this, the shear strength at a given interface distance can be output. Among them, OUTCAR is the output file of the first principle software VASP, which contains the optimized system energy. fEnergy[i][j][k] is a three-dimensional array defined by the program to store the energy of each POSCAR_i_j_k.

[0089] The program automatically traverses all i_j_k folders and determines the center position of the interface from the CONTCAR of each folder; it automatically traverses all i_j_k folders, integrates the CHGCAR of each folder in the x and y directions, and calculates the charge density at the center position of the interface And save it to the fCHGCAR_InterfaceCenter[i][j][k] three-dimensional array. Among them, CHGCAR and CONTCAR are the output files of the first principle software VASP, CHGCAR is the charge density file of the system, and CONTCAR is the atomic position file of the optimized system. fCHGCAR_InterfaceCenter[i][j][k] is a three-dimensional array defined by the program to save the interface center charge density of each POSCAR_i_j_k. in, is the charge density at the center of the interface; ρ(x,y,z,i,j,k) is the three-dimensional charge density saved in the CHGCAR file. At this point, the charge density at the center of the interface at each interface distance can be output. In order to characterize the shear strength with the charge density at the center of the interface, this application defines the charge density difference at the center of the interface in accordance with the shear strength. in, and They are the interfacial center charge densities corresponding to the saddle point configuration and the energy minimum configuration obtained from the frictional potential energy surface, respectively.

[0090] As an alternative implementation, in step S4, it specifically includes:

[0091] S41: Fit the functional relationship between the data in fEnergy[i][j][k] and the interfacial distance to obtain the adhesion energy corresponding to any interfacial distance.

[0092] S42: Based on the data in fEnergy[i][j][k] and the interfacial distance, establish a quantitative relationship between the load corresponding to the configuration at the interfacial distance and the interfacial distance.

[0093] S43: Based on the relationship between any interfacial distance and the adhesion energy and the quantitative relationship between the load and the interfacial distance, calculate the adhesion energy and the load work term corresponding to any load, and sum them to obtain the total energy of the configuration during the equal-load friction process.

[0094] S44: Fit the functional relationship between the data in fCHGCAR_InterfaceCenter[i][j][k] and the interfacial distance.

[0095] S45: Based on the quantitative relationship between the load and the interfacial distance and the relationship between the interfacial distance and the charge density of the interfacial center, obtain the charge density of the interfacial center of all configurations during the equal-load friction process.

[0096] Specifically, automatically fit the data and output the charge density during the equal-load friction process: Fit the functional relationship between E(i,j,k) and the interfacial distance h to obtain the adhesion energy E(i,j,h) at any interfacial distance. E(i,j,k) is the corresponding value in the three-dimensional array fEnergy[i][j][k]. Then, according to where f ext (i,j,h) is the load corresponding to the (i,j) configuration at the interfacial distance h, establish a quantitative relationship between f ext (i,j,h) and the interfacial distance h; Based on the relationships between the load and the interfacial distance and between the interfacial distance and the adhesion energy obtained in the above two steps, calculate the adhesion energy and the load work term corresponding to any load; Then, according to the total energy E(i,j,f ext ) of the configuration during the equal-load friction process being equal to the sum of the adhesion energy E(i,j,h(i,j,f ext )) and the load work f ext *h(i,j,f ext ), that is, E(i,j,f ext ) = E(i,j,h(i,j,f ext )) + f ext *h(i,j,f ext) to obtain the load f ext The interface distance and energy corresponding to each (i,j) configuration. Finally, fit the functional relationship between fCHGCAR_InterfaceCenter[i][j][k] and the interface distance h, and based on the relationship between the load and the interface distance and the relationship between the interface distance and the charge density at the interface center, obtain each (i,j) configuration and any load f ext The charge density at the corresponding interface center.

[0097] To save the time of researchers studying the evolution of charge density during the solid interface friction process, this application proposes a set of automated and high-throughput calculation methods for charge density. First, automatically construct all calculation models required for high-throughput calculation; then automatically call the first-principles software Vienna Ab-initio Simulation Package (VASP) based on density functional theory to submit calculations; then automatically output the system energy and charge density; finally, automatically fit the data and output the charge density during the equal-load friction process in these four steps. This method is applicable to all solid interface friction systems. Here, taking the graphene / graphene (Gr / Gr) interface as an example, specific and detailed implementation methods are given.

[0098] 1. Automatic modeling.

[0099] The Gr / Gr interface is formed by the AA stacking of two layers of graphene, each layer contains two C atoms, and the interlayer distance is The lattice constants in the x and y directions are As Figure 4 shown. Set the total number of steps for movement in the z direction to 100, and the distribution of the number of steps for upward and downward movement to 10 and 90. The distance moved per step in the z direction is The minimum positive period of the Gr / Gr interface in the x and y directions is Set the number of steps for movement in the x and y directions to 6 steps, then the distance moved per step is Move the upper half of the interface 6, 6, and 100 steps in the x, y, and z directions respectively, and the distances per step are and Construct 3600 calculation systems. Name the newly constructed systems using POSCAR_i_j_k, where i, j, and k are the number of steps for the upper half of the interface to move in the x, y, and z directions respectively. A typical POSCAR_i_j_k configuration is as Figure 4As shown, where POSCAR_0_0_0 is the initial configuration and also the Top configuration corresponding to the Gr / Gr interface, that is, the C atoms in the two layers have exactly the same positions in the x and y directions. POSCAR_2_4_0 corresponds to the Hollow configuration, that is, there is one C atom in each layer that can be projected to the center position of the six-membered ring in the other layer. This is also the configuration with the lowest energy of the Gr / Gr interface ( Figure 5 ), POSCAR_3_3_0 corresponds to the Saddle configuration, which is the configuration with the highest energy that must be passed through when sliding from the POSCAR_2_4_0 configuration to the adjacent lowest-energy POSCAR_4_2 configuration ( Figure 5 ).

[0100] 2. Automatic submission of calculations.

[0101] The parameters of VASP are set as follows: The interaction between electrons and ion cores is processed using the Projected AugmentedWave (PAW) pseudopotential method. The exchange-correlation potential between electrons uses the Perdew-Berke-Ernzerhof (PBE) functional in the generalized gradient approximation (GGA). The van der Waals dispersion interaction correction is considered using the grime's DFT-D3 method with Becke-Jonson (BJ) damping. The cutoff energy for plane-wave expansion is 400 eV. The convergence criterion for the electron step is set to 1x10-6 eV, and the convergence criterion for the atomic step is set to Use a 13*13*1 Monkhorst-Pack k-point mesh, and each system uses periodic boundary conditions. For each POSCAR_i_j_k, create a folder named i_j_k, automatically copy the INCAR, KPOINTS, POTCAR, POSCAR_i_j_k, and rvasp.sh files to the i_j_k folder, and rename POSCAR_i_j_k to POSCAR. Then enter the i_j_k folder in turn and automatically submit the task.

[0102] 3. Automatic output of system energy and charge density.

[0103] Enter the i_j_k folder in turn, read the configuration energy in the OUTCAR file, and save the read configuration energy to the three-dimensional array fEnergy[i][j][k]. Thus, the potential energy surface corresponding to the given interface distance can be output, as Figure 5 shown. As the interface distance decreases, the fluctuations of the frictional potential energy surface increase, but the overall morphology is similar. The configurations with the lowest energy always remain at (2, 4) and (4, 2), both of which correspond to the hollow configuration of Gr / Gr ( Figure 4), the configuration with the highest energy is (0, 0), i.e., the Top configuration ( Figure 4 ). Figure 6 (a) in shows the relationship between the energies of the (2, 4), (0, 0), and (3, 3) configurations and the interface distance. It can be seen that as the interface distance decreases, the total energy of the configurations decreases non-linearly, but the energies of the (0, 0) and (3, 3) configurations decrease faster, which will lead to a decrease in friction as the interface distance increases. Considering two sliding paths, (2, 4)-(3, 3)-(4, 2) and (2, 4)-(0, 0)-(4, 2), the corresponding shear strengths are as shown in Figure 6 (b). The friction indeed decreases as the interface distance increases, and the (2, 4)-(3, 3)-(4, 2) path corresponds to a lower shear strength.

[0104] Save the CHGCAR in the i_j_k folder as CHGCAR_i_j_k, and save the CONTCAR as CONTCAR_i_j_k. Then, successively read the position z of the center of the interface in the z direction from CONTCAR_i_j_k 0 ; then integrate CHGCAR_i_j_k in the x and y directions to calculate the charge density at the center of the interface As shown in Figure 7 , where Figure 7 (a) in is the three-dimensional charge density of the (2, 4) configuration of the Gr / Gr interface Figure 7 (b) in is the one-dimensional charge density integrated in the z direction corresponding to it. Figure 8 (a) in shows the relationship between the charge density at the center of the interface and the interface distance during the equidistant friction process. Similar to the energy results, as the interface distance increases, the charge density at the center of the interface also decreases. To characterize the shear strength using the charge density at the center of the interface, this application gives the relationship between the difference in the charge density at the center of the interface corresponding to the two sliding paths (2, 4)-(3, 3)-(4, 2) and (2, 4)-(0, 0)-(4, 2) and the interface distance, as shown in Figure 8 (b). Their relationship is opposite to the relationship between the shear strength and the interface distance. Therefore, there is a negative correlation between the shear strength and the difference in the charge density at the center of the interface, as shown in Figure 8 (c) and (d).

[0105] 4. Fit the data and output the charge density during the equidistant friction process.

[0106] Fit the functional relationship between E(i, j, k) and the interface distance h to obtain E(i, j, h), and then according to where f ext(i,j,h) is the load corresponding to the (i,j) configuration at the interface distance of h, and E(i,j,k) is the corresponding value in the three-dimensional array fEnergy[i][j][k]. Establish the quantitative relationship between f ext (i,j,h) and the interface distance h; then according to the total energy E(i,j,f ext ) of the configuration during the equal-load friction process is equal to the sum of the adhesion energy E(i,j,h(i,j,f ext )) and the work done by the load f ext *h(i,j,f ext ), that is, E(i,j,f ext ) = E(i,j,h(i,j,f ext )) + f ext *h(i,j,f ext ), the interface distance and energy of each (i,j) configuration corresponding to the load f ext are obtained. Thus, the potential energy surface corresponding to the given load can be output, as shown in Figure 9 . Among them, Figure 9 in (a) corresponds to the interface distance of 0 GPa; Figure 9 in (b) corresponds to the interface distance of 8.02 GPa; Figure 9 in (c) corresponds to the interface distance of 16.55 GPa. As the load increases, the fluctuations of the frictional potential energy surface increase, but the overall morphology is similar. The configurations with the lowest energy always remain at (2,4) and (4,2), both of which correspond to the Hollow configuration of Gr / Gr ( Figure 4 ), and the configuration with the highest energy is (0,0), that is, the Top configuration ( Figure 4 ). Figure 10 in (a) shows the relationship between the total energy of the system and the load. It can be seen that as the load increases, the total energies of the three configurations (2,4), (3,3), and (0,0) increase nearly linearly, but the energies of (0,0), (3,3), and (2,4) decrease in turn. This difference in energy mainly comes from the contribution of the work done by the load, as shown in Figure 10 in (b) and (c). Figure 10 in (d) shows the relationship between the shear strength and the load corresponding to the two sliding paths (2,4)-(3,3)-(4,2) and (2,4)-(0,0)-(4,2), and the corresponding friction coefficients are 0.036 and 0.349 respectively. Finally, the functional relationship between fCHGCAR_InterfaceCenter[i][j][k] and the interface distance h is fitted to obtain the relationship between the charge density at the interface center and the load f ext for each (i,j) configuration, as shown in Figure 11As shown in (a) of [reference], similar to the energy results, as the load increases, the charge density at the interface center also increases. However, as the load increases, the charge density differences between the (2, 4) and (3, 3) interfaces, as well as between the (2, 4) and (0, 0) interfaces, do not show obvious changes, as Figure 11 shown in (b) of [reference]. It should be noted that the charge density difference at the interface center cannot characterize the contribution of the load work to the shear strength, but only the contribution of adhesion to the shear strength, as Figure 11 shown in (c) and (d) of [reference], and there is a positive correlation between them.

[0107] This application also provides an application scenario that applies the above-mentioned high-throughput calculation and analysis method for charge density during solid interface friction. Specifically: The high-throughput calculation and analysis method for charge density during solid interface friction provided in this embodiment can be applied in the material high-throughput calculation scenario. The material high-throughput calculation scenario includes: an automatic modeling link, an automatic submission link, a link for determining the configuration energy and the charge density at the interface center, and a fitting link; based on the modeling data, automatic modeling is performed to obtain the modeled file; the modeling data includes: the POSCAR file, the number of movement steps of the upper part of the interface in the x, y, and z directions, and the distance of each movement step in the z direction; the POSCAR file is an interface configuration file used to specify the size of the interface and the position of each atom; based on the modeled file, an automatic submission folder is created, and the modeled file is moved to the automatic submission folder to complete the automatic submission task; according to the automatic submission folder, the configuration energy and the charge density at the interface center are determined; the configuration energy and the charge density at the interface center are fitted to output the charge density during the equal-load friction process.

[0108] Based on the same inventive concept, the embodiments of this application also provide a high-throughput calculation and analysis device for charge density during solid interface friction for implementing the above-mentioned high-throughput calculation and analysis method for charge density during solid interface friction. The solution provided by this device to solve the problem is similar to the solution described in the above method. Therefore, the specific limitations in one or more embodiments of the high-throughput calculation and analysis device for charge density during solid interface friction provided below can refer to the limitations on the high-throughput calculation and analysis method for charge density during solid interface friction in the above text, and will not be repeated here.

[0109] In an exemplary embodiment, as Figure 12 shown, a high-throughput calculation and analysis device for charge density during solid interface friction is provided. The high-throughput calculation and analysis device for charge density during solid interface friction includes:

[0110] An automatic modeling unit M1 is used to perform automatic modeling based on modeling data to obtain a modeled file. The modeling data includes: a POSCAR file, the number of moving steps of the upper part of the interface in the x, y, and z directions, and the distance of each moving step in the z direction. The POSCAR file is an interface configuration file used to specify the size of the interface and the position of each atom.

[0111] An automatic submission unit M2 is used to create an automatic submission folder based on the modeled file, and move the modeled file to the automatic submission folder to complete the automatic submission task.

[0112] A configuration energy and charge density determination unit M3 at the interface center position is used to determine the configuration energy and the charge density at the interface center position according to the automatic submission folder.

[0113] A fitting unit M4 is used to fit the configuration energy and the charge density at the interface center position, and output the charge density during the equal-load friction process.

[0114] In an exemplary embodiment, a computer device is provided. The computer device can be a server or a terminal, and its internal structure diagram can be as Figure 13 shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, abbreviated as I / O), and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, the processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program, and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The database of the computer device is used to store modeling data. The input / output interface of the computer device is used to exchange information between the processor and external devices. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, it implements a high-throughput calculation and analysis method for charge density during the solid interface friction process.

[0115] Those skilled in the art can understand that Figure 13 the structure shown in

[0116] In an exemplary embodiment, a computer device is further provided, including a memory and a processor. A computer program is stored in the memory, and when the processor executes the computer program, the above method embodiments are implemented.

[0117] In an exemplary embodiment, a computer-readable storage medium is provided, storing a computer program, and when the computer program is executed by a processor, the above method embodiments are implemented.

[0118] In an exemplary embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the above method embodiments are implemented.

[0119] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0120] Those of ordinary skill in the art can understand that all or part of the processes of implementing the above method embodiments can be completed by instructing relevant hardware through a computer program. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the above method embodiments. Among them, any reference to a memory, database, or other medium used in the embodiments provided in this application can include at least one of non-volatile and volatile memories. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0121] In each of the embodiments provided in this application, the databases involved may include at least one of a relational database and a non-relational database. The non-relational database may include a distributed database based on a blockchain, etc., without limitation. In each of the embodiments provided in this application, the processor may be a general-purpose processor, a central processing unit, a graphics processing unit, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., without limitation.

[0122] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as the scope recorded in this specification.

[0123] In this article, specific examples are used to elaborate on the principles and implementation manners of this application. The descriptions of the above embodiments are only used to help understand the method and its core idea of this application; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to this application.

Claims

1. A high-throughput calculation and analysis method for charge density during solid interface friction, characterized in that: The high-throughput calculation and analysis method for charge density during the solid interface friction process comprises: Based on the modeling data, automatic modeling is performed to obtain a modeled file; the modeling data includes: a POSCAR file, the number of movement steps of the interface part in the x, y, and z directions, and the distance of each movement step in the z direction; the POSCAR file is an interface configuration file, which is used to specify the size of the interface and the position of each atom; Based on the modeled file, an automatic submission folder is created, and the modeled file is moved to the automatic submission folder to complete the automatic submission task; According to the automatic submission folder, determining the configuration energy and the charge density at the center position of the interface; The configuration energy and the charge density at the center of the interface are fitted, and the charge density during the equal-load friction process is output.

2. The high-throughput calculation and analysis method for charge density during solid interface friction according to claim 1, characterized in that: Based on the modeling data, automatic modeling is performed to obtain the modeled files, including: Obtain modeling data; Calculate the length of the minimum period of the interface in the x and y directions, and calculate the length of each moving step in the x and y directions according to the given number of steps; According to the length of each moving step in the x, y, and z directions and the total number of steps, move the upper part of the interface in the POSCAR file in sequence, build and output the POSCAR file after each move, and rename it to POSCAR_i_j_k to obtain the modeled file.

3. The high-throughput calculation and analysis method for charge density during solid interface friction according to claim 2, characterized in that: Based on the modeled file, an automatic submission folder is created, and the modeled file is moved to the automatic submission folder to complete the automatic submission task, which specifically includes: Get INCAR files, KPOINTS files, POTCAR files and all POSCAR_i_j_k files; the INCAR file is the basic setting parameters of the first principle software VASP; the KPOINTS file is the K point setting; the POTCAR file is the potential function of each type of atom on the interface; the POSCAR_i_j_k file is the file after modeling; For each POSCAR_i_j_k file, create an automatic submission folder i_j_k, and move the POSCAR_i_j_k file, INCAR file, KPOINTS file, and POTCAR file to the automatic submission folder i_j_k; Automatically traverse all automatic submission folders and submit calculation tasks.

4. The high-throughput calculation and analysis method for charge density during solid interface friction according to claim 3, characterized in that: The determination of the configuration energy specifically includes: Automatically traverse all automatically submitted folders and read the configuration energy from the OUTCAR files in each folder; the OUTCAR file is the output file of the first principle software VASP, which contains the optimized system energy; The configuration energy is automatically saved in fEnergy[i][j][k]; fEnergy[i][j][k] is a three-dimensional array used to save the energy of each modeled file.

5. The high-throughput calculation and analysis method for charge density during solid interface friction according to claim 4, characterized in that: The determination of the charge density at the center of the interface specifically includes: Automatically traverse all automatically submitted folders and determine the center position of the interface in each configuration from the CONTCAR files in each folder; the CONTCAR files are optimized systematic atomic position files; Automatically traverse all automatically submitted folders, integrate the CHGCAR files in each folder in the x and y directions, calculate the charge density at the center of the interface in each configuration, and save the charge density at the center of the interface in each configuration to fCHGCAR_InterfaceCenter[i][j][k]; the CHGCAR file is the charge density file of the system; the fCHGCAR_InterfaceCenter[i][j][k] is a three-dimensional array used to save the charge density at the center of the interface of each modeled file.

6. The high-throughput calculation and analysis method for charge density during solid interface friction according to claim 5, characterized in that: The calculation formula of the charge density at the center of the interface is: in, is the charge density at the center of the interface; ρ(x, y, z, i, j, k) is the three-dimensional charge density saved in the CHGCAR file.

7. The high-throughput calculation and analysis method for charge density during solid interface friction according to claim 6, characterized in that: The configuration energy and the charge density at the center of the interface are fitted to output the charge density during the equal-load friction process, specifically including: Fitting the functional relationship between the data in fEnergy[i][j][k] and the interface distance to obtain the adhesion energy corresponding to any interface distance; Based on the data in fEnergy[i][j][k] and the interface distance, a quantitative relationship between the load and the interface distance corresponding to the configuration at the interface distance is established; Based on the relationship between any interface distance and adhesion energy and the quantitative relationship between the load and the interface distance, the adhesion energy and the load work term corresponding to any load are calculated, and the total energy of the configuration in the equal load friction process is obtained by summing them up; Fitting the functional relationship between the data in fCHGCAR_InterfaceCenter[i][j][k] and the interface distance; Based on the quantitative relationship between the load and the interface distance and the relationship between the interface distance and the charge density at the interface center, the interface center charge density of all configurations in the equal-load friction process is obtained.

8. The high-throughput calculation and analysis method for charge density during solid interface friction according to claim 7, characterized in that: The quantitative relationship between the load and the interface distance of the configuration is expressed as follows: Among them, f ext (i, j, h) is the load corresponding to the (i, j) configuration when the interface distance is h, E(i, j, h) is the adhesion energy at any interface distance, and h is the interface distance.

9. The high-throughput calculation and analysis method for charge density during solid interface friction according to claim 7, characterized in that: The calculation formula for the total energy of the configuration during the equal load friction process is: E(i), j, f ext )=E(i,j,h(i,j,f ext ))+f ext *h(i,j,f ext ); Among them, E(i, j, f ext ) is the total energy of the configuration during the friction process with equal load, E(i, j, h(i, j, f ext )) is the adhesion energy corresponding to any load, f ext *h(i,j,f ext ) is the load work corresponding to any load.

10. A high-throughput calculation and analysis device for charge density during solid interface friction, characterized in that: The high-throughput charge density calculation and analysis device during the solid interface friction process comprises: An automatic modeling unit, used for automatically modeling based on modeling data to obtain a modeled file; the modeling data includes: a POSCAR file, the number of movement steps of the interface part in the x, y, and z directions, and the distance of each movement step in the z direction; the POSCAR file is an interface configuration file, used for specifying the size of the interface and the position of each atom; An automatic submission unit, used to create an automatic submission folder based on the modeled file, and move the modeled file to the automatic submission folder to complete the automatic submission task; A configuration energy and charge density determination unit at the center of the interface, used to determine the configuration energy and charge density at the center of the interface according to the automatic submission folder; The fitting unit is used to fit the configuration energy and the charge density at the center position of the interface, and output the charge density during the equal-load friction process.

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