Hydrogen molecule polarization force field responding to electric field change and construction method and application thereof
By introducing a virtual particle module into the hydrogen molecule module and utilizing a specific interactive force field, the polarization of hydrogen molecules under the action of an electric field is achieved, and the problem of lack of a polarization force field in the prior art is solved, and the efficiency and accuracy of hydrogen molecule simulation are improved.
Patent Information
- Application Number
- CN202510098271.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-22
- Publication Date
- 2025-06-03
AI Technical Summary
The lack of a force field in the prior art that can achieve polarization of hydrogen molecules in response to electric field changes, limiting the scale, accuracy and efficiency of hydrogen molecules simulation.
A hydrogen molecule polarization force field is designed to respond to changes in the electric field. By introducing a virtual particle module with inducing charge into the hydrogen molecule module, and using LJ interaction and simple harmony potential to interact, the polarization of hydrogen molecules under the action of the electric field is achieved.
It has achieved polarization in response to electric field changes, improving the scale, accuracy and efficiency of hydrogen molecular simulation, and is of great significance to studying the impact of electric field on hydrogen molecules and the design of hydrogen storage materials.
Smart Images
Figure CN120089212A_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of computer simulation, and particularly relates to a hydrogen molecule polarization force field responsive to electric field changes, a construction method thereof, and an application thereof. Background Technique
[0002] With the development of computer simulation technology, computational chemistry simulation provides an accurate method for studying the properties of different substances. Computational chemistry simulation can be classified into quantum mechanics methods and molecular simulation methods according to principles. Quantum mechanics methods can calculate the behavior of electrons by solving the Schrödinger equation, including ab initio methods, density functional theory and other methods. The calculation results of quantum mechanics methods are very accurate, but the systems that can be simulated are very small and the calculation speed is extremely slow. Molecular simulation methods are based on classical Newtonian mechanics to simulate the behavior of molecules, ignoring the electron motion. Molecular simulation methods can predict and analyze the properties and behaviors of molecules through a large number of numerical calculations. Compared with experimental methods and quantum mechanics methods, molecular simulation has the advantages of low cost, high efficiency, high accuracy, etc. As the key of molecular simulation methods, the force field affects the accuracy and credibility of simulation results. The force field is an empirical expression of the potential energy surface, representing the interaction relationship between different particles. There are many forms of force fields, and they have different application ranges and limitations.
[0003] As a clean and green energy source, hydrogen has received extensive attention in the fields of new energy, energy storage materials, energy storage technologies, etc. The hydrogen molecule itself is a non-polar molecule. In the case of applying an additional electric field, the hydrogen molecule will be polarized to generate an induced dipole. In the field of solid hydrogen storage materials, existing research results have proved that applying an additional electric field is beneficial to increasing the hydrogen storage capacity of the material. Currently, most of the simulation studies on the polarization behavior of hydrogen are based on quantum mechanics theories such as density functional theory and first-principles. Although this method does not require a force field to describe the potential energy surface, the number of hydrogen molecules that can be simulated is limited and the efficiency is low.
[0004] Therefore, there is an urgent need for a force field that can polarize hydrogen molecules in response to an electric field. However, for hydrogen molecules, there are many widely used traditional non-polarizable force fields, such as the Silvera-Goldman force field, the Darkrim force field, the Marx force field, and the Buch force field, etc. The above-mentioned force fields are all non-polarizable force fields, and the hydrogen molecules described by them cannot respond to the change of the electric field during the molecular simulation. The commonly used polarizable force field in molecular simulation is the CHARMM force field, but it is mostly used in the research of biological macromolecules and other fields, and the hydrogen atoms are regarded as non-polarizable atoms, so a polarizable hydrogen molecule cannot be constructed. In short, there is currently no force field that can polarize hydrogen molecules in response to an electric field, which is a challenging problem. Therefore, it is particularly important to design a polarizable force field of hydrogen molecules that responds to the change of the electric field. It can be used for the molecular simulation research of a large number of hydrogen molecules and is of great significance for studying the influence of the electric field on hydrogen molecules and the design of hydrogen storage materials, etc. Summary of the Invention
[0005] An object of the present invention is to provide a polarizable force field of hydrogen molecules that responds to the change of the electric field, effectively solving the problem that there is currently a lack of a force field that can polarize hydrogen molecules in response to the electric field.
[0006] To solve the above technical problems, the technical solution adopted by the present invention is:
[0007] A polarizable force field of hydrogen molecules that responds to the change of the electric field is applied to several hydrogen molecule models, and the hydrogen molecule models are composed of a hydrogen molecule module and a virtual particle module with induced charges.
[0008] The hydrogen molecule module is used to represent a coarse-grained hydrogen molecule and is composed of a single first particle.
[0009] The first particle has an LJ interaction for representing the non-bonded interaction between hydrogen molecule models, and has a negative charge for calculating the electrostatic interaction.
[0010] The virtual particle module is used to represent the induced charge after the hydrogen molecule model is polarized and is composed of a single second particle.
[0011] The second particle does not have an LJ interaction, but has a positive charge for balancing the hydrogen molecule module and making the hydrogen molecule model electrically neutral.
[0012] The hydrogen molecule module and the virtual particle module interact with each other through a harmonic potential. When there is no additional electric field, the hydrogen molecule module and the virtual particle module coincide, indicating that the hydrogen molecule model has not been polarized; when there is an additional electric field, the hydrogen molecule module and the virtual particle module do not coincide, indicating that the hydrogen molecule model has been polarized to generate an induced dipole.
[0013] Furthermore, the LJ interaction is expressed as: In the formula, u represents the LJ interaction, and ε ij represents the depth of the potential well, and σ ij represents the particle collision diameter, and r ij represents the distance between the first particle i and the first particle j.
[0014] Furthermore, the harmonic potential is expressed as: E’ = K(r - r 0 ) 2 , where E’ represents the harmonic potential, K represents the spring constant, r represents the distance between the first particle and the second particle, and r 0 represents the equilibrium distance.
[0015] Furthermore, the hydrogen molecule module and the virtual particle module have equal amounts of opposite charges, and the amount of charge is: q 2 = 2Kα, where q represents the amount of charge, K represents the spring constant, and α represents the polarizability of the hydrogen molecule model.
[0016] Another object of the present invention is to provide a method for constructing a hydrogen molecule polarization force field that responds to changes in the electric field described in the above embodiments, including the following steps: S1. According to the polarizability of the hydrogen molecule model, set the hydrogen molecule module and the virtual particle module to carry equal amounts of negative charge and positive charge respectively, and the hydrogen molecule model has no net charge.
[0017] S2. Set the sum of the masses of the virtual particle module and the hydrogen molecule module to be the same as the mass of the actual hydrogen molecule to ensure that the mass of the hydrogen molecule remains unchanged.
[0018] S3. Set the parameters of the LJ interaction of the first particle of the hydrogen molecule module with reference to the Buch hydrogen force field.
[0019] S4. Set the equilibrium distance of the harmonic potential to 0 to ensure that the positive and negative charge centers of the hydrogen molecule model coincide in the initial state and there is no dipole moment. At this time, the virtual particle module performs harmonic motion around the hydrogen molecule module under the action of the harmonic potential.
[0020] S5. Generate a certain number of hydrogen molecule models for molecular simulation calculations.
[0021] S6. In the absence of an externally applied electric field, the hydrogen molecule model will not be polarized, the hydrogen molecule module coincides with the virtual particle module, and the hydrogen molecule model remains in the initial state.
[0022] S7. When an additional electric field is applied, the hydrogen molecule model is polarized, and the hydrogen molecule module and the virtual particle module no longer coincide. Since the hydrogen molecule module and the virtual particle module carry equal amounts of negative and positive charges respectively, the virtual particle module will displace along the direction of the electric field relative to the hydrogen molecule module, and this displacement results in an electric field-induced dipole moment μ: μ = αE, where μ represents the dipole moment, α represents the polarizability of the hydrogen molecule model, and E represents the electric field strength.
[0023] Through the above steps, the hydrogen molecule polarization force field in response to the change of the electric field is constructed.
[0024] Another object of the present invention is to provide an application of the hydrogen molecule polarization force field in response to the change of the electric field described in the above embodiments, which is used for hydrogen molecule simulation, calculating the induced dipole moment of hydrogen, and reflecting the polarization degree of hydrogen molecules.
[0025] First, construct a hydrogen molecule model containing a virtual particle module; secondly, fill a certain number of hydrogen molecule models in the simulation box, set the hydrogen molecule polarization force field, and add a constant electric field on both sides of the simulation box; then, initialize the velocity of the hydrogen molecule model and perform molecular simulation under the canonical ensemble, and the hydrogen molecule model will be polarized under the action of the electric field; finally, perform statistical averaging on the dipole moments of the hydrogen molecule models in the simulation trajectory, so as to reflect the polarization degree of hydrogen molecules.
[0026] Compared with the prior art, the beneficial technical effects of the present invention are:
[0027] In the present invention, an additional charged virtual particle module is bound to the hydrogen molecule module with a single LJ interaction site, and the virtual particle module and the hydrogen molecule module interact with each other with a harmonic potential, so as to realize the polarization of hydrogen molecules in response to the change of the electric field. The hydrogen molecule polarization force field in response to the change of the electric field provided by the present invention enables hydrogen molecules to be polarized in response to the electric field, which is beneficial to improving the scale, accuracy and efficiency of hydrogen molecule simulation. Description of the Drawings
[0028] Figure 1 It is a schematic diagram of a hydrogen molecule model of the polarization force field when there is no additional electric field.
[0029] Figure 2 It is a schematic diagram of a hydrogen molecule model of the polarization force field when there is an additional electric field, where the arrow indicates the direction of the electric field, E represents the electric field strength, and q represents the charge.
[0030] Description of the reference numerals: hydrogen molecule module - 1; virtual particle module - 2. Detailed Embodiments
[0031] Example 1: A hydrogen molecule polarization force field responsive to electric field changes is applied to several hydrogen molecule models, which are composed of a hydrogen molecule module 1 and a virtual particle module 2 with induced charges, as Figure 1 shown.
[0032] The hydrogen molecule module 1 is used to represent a coarse-grained hydrogen molecule and consists of a single first particle; the first particle has a Lennard-Jones interaction (LJ interaction) for representing non-bonded interactions between hydrogen molecule models, and has a negative charge for electrostatic interaction calculations.
[0033] The virtual particle module 2 is used to represent the induced charge after the hydrogen molecule model is polarized and consists of a single second particle; the second particle does not have an LJ interaction, but has a positive charge for balancing the hydrogen molecule module 1 and making the hydrogen molecule model electrically neutral.
[0034] The LJ interaction is expressed as: In the formula, u represents the LJ interaction, ε ij represents the depth of the potential well, σ ij represents the particle collision diameter, r ij represents the distance between the first particle i and the first particle j.
[0035] The hydrogen molecule module 1 and the virtual particle module 2 interact through a harmonic potential, and the harmonic potential is expressed as: E’ = K(r - r 0 ) 2 , in the formula, E’ represents the harmonic potential, K represents the spring constant, r represents the distance between the first particle and the second particle, and r 0 represents the equilibrium distance.
[0036] The hydrogen molecule module 1 and the virtual particle module 2 have equal amounts of opposite charges, and the charge quantity is: q 2 = 2Kα, in the formula, q represents the charge quantity, K represents the spring constant, and α represents the polarizability of the hydrogen molecule model.
[0037] When there is no additional electric field, as Figure 1 shown, the hydrogen molecule module 1 and the virtual particle module 2 coincide, indicating that the hydrogen molecule model has not been polarized; when there is an additional electric field, as Figure 2 shown, the hydrogen molecule module 1 and the virtual particle module 2 do not coincide, indicating that the hydrogen molecule model has been polarized to generate an induced dipole.
[0038] Example 2: The method for constructing a hydrogen molecule polarization force field responsive to electric field changes as described in Example 1 includes the following steps: S1. According to the polarizability of the hydrogen molecule model, the hydrogen molecule module 1 and the virtual particle module 2 are respectively set to carry equal amounts of negative and positive charges, and the overall hydrogen molecule model has no net charge.
[0039] S2. To ensure that the mass of the hydrogen molecule remains unchanged, the mass of the virtual particle module 2 is set to 0.4 g / mol, the mass of the hydrogen molecule module 1 is set to 1.616 g / mol, and the total mass of the virtual particle module 2 and the hydrogen molecule module 1 is 2.016 g / mol, which is the same as the actual mass of the hydrogen molecule.
[0040] S3. The parameters of the LJ interaction of the first particle of the hydrogen molecule module 1 are set with reference to the Buch hydrogen force field, taking ε ij = 0.06796 kcal / mol,
[0041] S4. The equilibrium distance r of the harmonic potential is set to 0 to ensure that the positive and negative charge centers of the hydrogen molecule model coincide in the initial state and there is no dipole moment. At this time, the virtual particle module 2 makes a harmonic motion around the hydrogen molecule module 1 under the action of the harmonic potential, and the spring constant K of the harmonic potential is set to 0 ...
[0042] S5. Generate a certain number of hydrogen molecule models for molecular simulation calculations.
[0043] S6. In the absence of an applied additional electric field, the hydrogen molecule model will not be polarized, the hydrogen molecule module 1 coincides with the virtual particle module 2, and the hydrogen molecule model remains in the initial state.
[0044] S7. When an additional electric field is applied, the hydrogen molecule model is polarized, and the hydrogen molecule module 1 and the virtual particle module 2 no longer coincide, that is, the positive and negative charge centers do not coincide. Since the hydrogen molecule module 1 and the virtual particle module 2 carry equal amounts of negative and positive charges respectively, the virtual particle module 2 will generate a displacement along the electric field direction relative to the hydrogen molecule module 1, and this displacement results in an electric field-induced dipole moment μ: μ = αE, where μ represents the dipole moment, α represents the polarizability of the hydrogen molecule model, and E represents the electric field strength.
[0045] Through the above steps, a hydrogen molecule polarization force field responsive to electric field changes is constructed. It is used for hydrogen molecule simulation, calculating the induced dipole moment of hydrogen, and reflecting the polarization degree of hydrogen molecules, which is of great significance for studying the influence of electric fields on hydrogen molecules, the design of hydrogen storage materials, etc.
[0046] The specific application process is as follows: First, construct a hydrogen molecule model containing the virtual particle module 2, such asFigure 1 as shown
[0047] Secondly, a certain number of hydrogen molecule models are filled in the simulation box, and the polarization force field of hydrogen molecules is set, including LJ interaction, harmonic type, charge and mass. A constant electric field is added to both sides of the simulation box.
[0048] Then, the velocities of the hydrogen molecule models are initialized, and molecular simulations are carried out in the canonical (NVT) ensemble. The hydrogen molecule models will be polarized under the action of the electric field.
[0049] Finally, the induced dipole moments of the hydrogen molecule models in the simulation trajectories are statistically averaged to reflect the polarization degree of hydrogen molecules.
[0050] The hydrogen molecule polarization force field that responds to the change of the electric field provided by the present invention can be used for the molecular simulation research of a large number of hydrogen molecules, and can quickly and accurately describe the polarization behavior of hydrogen. This hydrogen molecule polarization force field that responds to the change of the electric field is of great significance for studying the influence of the electric field on hydrogen molecules, the design of hydrogen storage materials, etc.
[0051] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by those skilled in the art within the essence of the present invention should also fall within the protection scope of the present invention.
Claims
1. A hydrogen molecule polarization force field that responds to electric field changes, characterized in that: Applied to several hydrogen molecule models, the hydrogen molecule models are composed of hydrogen molecule modules and virtual particle modules with induced charges; The hydrogen molecule module is used to represent coarse-grained hydrogen molecules, and is composed of a single first particle; The first particle has an LJ interaction for representing a non-bonding interaction between hydrogen molecule models and a negative charge for electrostatic interaction calculation; The virtual particle module is used to represent the induced charge of the hydrogen molecule model after polarization, and is composed of a single second particle; The second particle does not have LJ interaction, but has a positive charge for balancing the hydrogen molecule model and making the hydrogen molecule model uncharged; The hydrogen molecule module and the virtual particle module interact with each other through simple harmonic potential. When there is no additional electric field, the hydrogen molecule module and the virtual particle module overlap, indicating that the hydrogen molecule model is not polarized; when there is an additional electric field, the hydrogen molecule module and the virtual particle module do not overlap, indicating that the hydrogen molecule model is polarized and an induced dipole is generated.
2. The hydrogen molecule polarization force field that responds to electric field changes according to claim 1, characterized in that: The LJ interaction is expressed as: Where u represents the LJ interaction, ε ij represents the potential well depth, σ ij represents the particle collision diameter, r ij represents the distance between the first particle i and the first particle j.
3. The hydrogen molecule polarization force field that responds to electric field changes according to claim 2, characterized in that: The simple harmonic potential is expressed as: E' = K(r-r0) 2 , where E' represents the simple harmonic potential, K represents the spring constant, r represents the distance between the first particle and the second particle, and r0 represents the equilibrium distance.
4. The hydrogen molecule polarization force field that responds to electric field changes according to claim 3, characterized in that: The hydrogen molecule module and the virtual particle module have equal but opposite charges, and the charge is: q 2 =2Kα, where q represents the charge, K represents the spring constant, and α represents the polarizability of the hydrogen molecule model.
5. The method for constructing a hydrogen molecule polarization force field that responds to electric field changes according to any one of claims 1 to 4, characterized in that: The following steps are involved: S1. According to the polarizability of the hydrogen molecule model, the hydrogen molecule module and the virtual particle module are set to have equal negative and positive charges respectively, and the hydrogen molecule model has no net charge; S2. Set the sum of the masses of the virtual particle module and the hydrogen molecule module to be the same as the actual mass of the hydrogen molecule to ensure that the mass of the hydrogen molecule remains unchanged; S3, the parameters of the LJ interaction of the first particle of the hydrogen molecule module are set with reference to the Buch hydrogen force field; S4. Set the equilibrium distance of the simple harmonic potential to 0 to ensure that the positive and negative charge centers of the hydrogen molecule model coincide in the initial state and there is no dipole moment. At this time, the virtual particle module performs simple harmonic motion around the hydrogen molecule module under the action of the simple harmonic potential. S5, generating a certain number of hydrogen molecule models for molecular simulation calculations; S6. In the absence of an additional electric field, the hydrogen molecule model will not be polarized, the hydrogen molecule module overlaps with the virtual particle module, and the hydrogen molecule model remains in the initial state; S7. When an additional electric field is applied, the hydrogen molecule model is polarized, and the hydrogen molecule module and the virtual particle module no longer overlap. Since the hydrogen molecule module and the virtual particle module carry equal negative and positive charges, respectively, the virtual particle module will be displaced along the electric field direction relative to the hydrogen molecule module. The displacement results in an electric field-induced dipole moment μ: μ=αE, where μ represents the dipole moment, α represents the polarizability of the hydrogen molecule model, and E represents the electric field strength. Through the above steps, the polarization force field of hydrogen molecules that responds to changes in the electric field is constructed.
6. Application of the hydrogen molecule polarization force field that responds to electric field changes according to any one of claims 1 to 4 or the hydrogen molecule polarization force field constructed by the construction method according to claim 5, characterized in that: Used for hydrogen molecule simulation to calculate the induced dipole moment of hydrogen and the polarization degree of the reacting hydrogen molecules.
7. The application of the hydrogen molecule polarization force field in response to electric field changes according to claim 6, characterized in that: First, a hydrogen molecule model including a virtual particle module is constructed; Secondly, fill a certain number of hydrogen molecule models in the simulation box, set the polarization force field of the hydrogen molecules, and add a constant electric field on both sides of the simulation box; Then, the velocity of the hydrogen molecule model is initialized, and molecular simulation is performed under the canonical ensemble. The hydrogen molecule model will be polarized under the action of the electric field. Finally, the dipole moment of the hydrogen molecule model in the simulation trajectory is statistically averaged to reflect the polarization degree of the hydrogen molecule.