Gas phase molecular energy theory calculation correction method, device and medium

Abstract

The present application relates to a gas phase molecular energy theory calculation correction method, device and medium, the method comprises the following steps: obtaining the experimental measurement value and the theoretical calculation value of each gas phase molecular energy under the current gas phase molecular system, and constructing a gas phase molecular energy dataset; based on the gas phase molecular energy dataset, an energy difference linear equation set is established; the least square method is used to optimize and fit the energy difference linear equation set, and the optimal energy correction value is obtained; based on the optimal energy correction value, the theoretical calculation value is corrected. Compared with the prior art, the rationality and accuracy of the gas phase molecular energy correction are improved, and most of the gas phase molecular energy correction can be comprehensively associated, which is more universal.

Description

Technical Field

[0001] This invention belongs to the field of computational chemistry, and in particular relates to a method, device and medium for correcting theoretical calculations of gas-phase molecular energy based on constrained least squares method. Background Technology

[0002] With the enrichment and refinement of modern quantum chemistry theory and the rapid development of computing power, computational chemistry has been widely applied in various fields such as physics, chemistry, biology, and environmental science. In particular, density functional theory (DFT) methods, based on first principles, have been widely used in materials science research due to their advantages in describing microscopic interatomic interactions and chemical behavior, including high accuracy, large scale, and high speed. In the study of gas-phase molecules, theoretical calculations can usually explain and predict the structure, properties, and reactivity of molecules. However, the theoretical calculation results of gas-phase molecule energies often deviate from experimental data. The main reason for this energy deviation is the inherent approximation of the DFT calculation method itself. Therefore, an effective correction method is needed to improve the accuracy and reliability of theoretical calculation results. Summary of the Invention

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a reliable, accurate, and widely applicable method, device, and medium for calculating and correcting gas-phase molecular energy based on the constrained least squares method.

[0004] The objective of this invention can be achieved through the following technical solutions:

[0005] A method for correcting theoretical calculations of gas-phase molecular energy based on constrained least squares includes the following steps:

[0006] Obtain experimental measurements and theoretical calculations of the energy of each gas phase molecule in the current gas phase molecular system, and construct a gas phase molecular energy dataset;

[0007] A set of linear equations for energy differences was established based on the aforementioned gas phase molecular energy dataset.

[0008] The energy difference linear equations are optimized and fitted using the constrained least squares method to obtain the optimal energy correction value.

[0009] The theoretically calculated value is corrected based on the optimal energy correction value.

[0010] Furthermore, the theoretical calculation values ​​are obtained based on density functional theory.

[0011] Furthermore, when calculating the theoretically calculated value based on density functional theory, zero-point energy correction is considered.

[0012] Furthermore, the establishment of the linear equation system of the energy difference model is specifically as follows:

[0013] Based on the molecular formula of the reactant molecule, the reactant molecule material matrix Mchem;

[0014] Establish the material conservation equation Mchem T ×v=0, where v is the reaction cycle basis vector;

[0015] By adding a correction term to the theoretical calculations, a system of linear equations for energy difference is established:

[0016] v T ×E exp =v T ×(E DFT +E x )

[0017] Among them, E exp Expressed as experimental values ​​of gas-phase molecular energy, E DFT Expressed as the theoretical value of gas phase molecular energy, E x This is expressed as the gas phase molecular energy correction value.

[0018] Furthermore, the reaction molecular material matrix Mchem is an n×m matrix, where n represents the types of reaction molecules and m represents the types of elements.

[0019] Furthermore, the reaction cycle basis vector v is obtained by solving the material conservation equation using linear algebra.

[0020] Furthermore, when optimizing the linear equations of the energy difference using the constrained least squares method, the objective function is to optimize the gas phase molecule energy correction value E. x To minimize the sum of squares, the constraint condition is expressed as v. T ×E x =b, where b = v T ×(E exp -E DFT ).

[0021] This invention also provides a calibration device for theoretical calculation of gas-phase molecular energy based on constrained least squares method, comprising:

[0022] The data collection module is used to acquire experimental measurements and theoretical calculations of the energy of each gas phase molecule in the current gas phase molecular system, and to construct a gas phase molecule energy dataset.

[0023] An equation construction module is used to establish a set of linear equations for energy differences based on the gas phase molecular energy dataset.

[0024] The fitting optimization module is used to optimize and fit the linear equations of the energy difference using the constrained least squares method to obtain the optimal energy correction value.

[0025] The correction module is used to correct the theoretically calculated value based on the optimal energy correction value.

[0026] The present invention also provides a device for calculating and correcting gas phase molecular energy theory based on constrained least squares method, comprising one or more processors, a memory, and one or more programs stored in the memory, wherein the one or more programs include instructions for executing the gas phase molecular energy theory calculation and correction method based on constrained least squares method as described above.

[0027] The present invention also provides a computer-readable storage medium including one or more programs executable by one or more processors of an electronic device, said one or more programs including instructions for performing the gas phase molecular energy theory calculation correction method based on constrained least squares as described above.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] (1) By comparing and analyzing theoretical calculation results with experimental data, and considering overall efficiency, this invention obtains gas phase molecular energy correction values, which can make the corrected theoretical calculation values ​​better fit the experimental data. The correction method has high reliability and accuracy.

[0030] (2) This invention uses constrained least squares method for optimization fitting, takes into account the collective efficiency of gas phase molecular system, so as to obtain the optimal correction model, which can be applied to gas phase molecules of different sizes, structures and chemical properties. Traditional methods, such as correction methods that use common atoms or stable molecules as reference states, are often limited to specific types of gas phase molecules or specific correction models.

[0031] (3) This invention is applicable to different gas phase molecular systems. The resulting gas phase molecular energy correction values ​​are concentrated and small, avoiding large correction values ​​that could affect the original properties of gas phase molecules, such as adsorption energy. This invention comprehensively improves the accuracy of correction and can comprehensively correlate the correction of most gas phase molecular energies, making it more universal.

[0032] (4) The present invention can realize the automated energy correction process through computer program, freeing up manpower and reducing human error, especially for complex systems with a large number of molecules. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the process of the present invention;

[0034] Figure 2 These are two schematic diagrams of matrices in an embodiment of the present invention, wherein (a) is the reactant molecular material matrix Mchem; and (b) is the reaction cycle basis vector v.

[0035] Figure 3 The figures show the distribution curves of the energy correction values ​​calculated by 16 different gas phase molecular theories under different correction methods in the embodiments of the present invention. Among them, E1 is the gas phase molecular energy correction value obtained by using the method of the present invention, E2 is the gas phase molecular energy correction value obtained by correction based on the energies of C, H, O, and N, E3 is the gas phase molecular energy correction value obtained by correction based on the energies of CO2, H2, H2O, and N2, and E4 is the gas phase molecular energy correction value obtained by correction based on the energies of CH4, H2, H2O, and N2. Detailed Implementation

[0036] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0037] refer to Figure 1 As shown, this embodiment provides a method for correcting theoretical calculations of gas-phase molecular energy based on constrained least squares, including the following steps:

[0038] S1. Obtain the experimental and theoretical measurements of the energy of each gas phase molecule in the current gas phase molecular system, and construct a gas phase molecular energy dataset.

[0039] In a specific implementation, the theoretical calculation value is the result obtained from density functional theory (DFT) calculation, and zero-point energy correction is taken into account.

[0040] Table 1 shows the gas phase molecular energy dataset of a gas phase molecular system containing 16 types of gas phase molecules.

[0041] Table 1

[0042] <![CDATA[H2]]> 0.00 -6.52 <![CDATA[O2]]> 0.00 -9.72 <![CDATA[N2]]> 0.00 -16.52 <![CDATA[H2O]]> -2.51 -13.72 <![CDATA[NH3]]> -0.48 -18.65 NO 0.95 -12.13 <![CDATA[N2O]]> 0.85 -21.16 <![CDATA[NO2]]> 0.34 -18.14 <![CDATA[CH2O]]> -1.13 -21.43 <![CDATA[CH4]]> -0.77 -22.95 CO -1.15 -14.68 <![CDATA[CO2]]> -4.08 -22.69 <![CDATA[CH3OH]]> -2.08 -28.92 <![CDATA[C2H2O]]> -0.49 -30.11 <![CDATA[CH2O2]]> -3.93 -28.93 <![CDATA[H2O2]]> -1.41 -17.45

[0043] S2. Establish a set of linear equations for energy differences based on the gas phase molecular energy dataset.

[0044] In a specific implementation, based on the difference between the experimentally measured and theoretically calculated values ​​of gas phase molecular energy in the aforementioned gas phase molecular energy dataset, an energy difference model is established and represented as a system of linear equations, specifically including:

[0045] (21) Based on the molecular formula of the reactant molecule, establish an n×m reactant molecule material matrix Mchem, where n represents the type of reactant molecule and m represents the type of element. The material matrix Mchem records the number of different atoms contained in each molecule.

[0046] (22) Establish the material conservation equation, expressed as Mchem T ×v=0, where v is the reaction cycle basis vector, and the material conservation equation Mchem can be solved by linear algebra. T ×v = 0 is obtained;

[0047] (23) To ensure that the experimentally measured and theoretically calculated values ​​of the reaction cycle basis vector v are thermodynamically consistent, a correction term E is added to the theoretically calculated value. x , represented as:

[0048] v T ×E exp =v T ×(E DFT +E x )

[0049] Among them, E exp Expressed as experimental values ​​of gas-phase molecular energy, E DFT Expressed as the theoretical value of gas phase molecular energy, E x These are expressed as gas phase molecular energy correction values, all of which are vectors.

[0050] In this embodiment, a 16×4 reaction molecular material matrix Mchem was established for a gas-phase molecular system containing 16 types of gas-phase molecules. Mchem contains 16 molecules and 4 elements, and records the number of different atoms contained in each molecule, such as... Figure 2 As shown in (a). Based on the material conservation equation, the reaction cycle basis vector v is obtained by linear algebra, which is a 16×12 matrix, as shown in (a). Figure 2 As shown in (b).

[0051] S3. The energy difference linear equation system is optimized and fitted using the constrained least squares method to obtain the optimal energy correction value.

[0052] In a specific implementation, when optimizing and fitting the energy difference linear equations using the constrained least squares method, the objective function is to optimize the gas phase molecule energy correction value E. x The sum of squares is minimized, i.e., f = E. x T ×E x Minimum, the constructed constraint condition is expressed as v T ×E x =b, where b = v T ×(Eexp -E DFT ).

[0053] In this embodiment, the process of fitting optimization using the constrained least squares method includes:

[0054] (31) Introducing Lagrange multipliers into the objective function, expressed as f = E x T ×E x +2×r T ×(v T ×E x -b);

[0055] (32) Take the derivative of the objective function and set the derivative to 0 to find the minimum point, i.e., df / dE. x =2×Ex+2×v×r=0, solving for E gives E x = -v×r;

[0056] (33) Combining the constraint condition v T ×E x =b, we can solve for the Lagrange multiplier r, and get r = -(v T ×v) -1 ×b;

[0057] (34) Substitute r into the correction formula E x = -v×r, to obtain the energy correction value E x =v×(v T ×v) -1 ×b;

[0058] (35) Substitute b into the correction formula E x =v×(v T ×v) -1 ×b, to obtain the final energy correction value E x =v×(v T ×v) -1 ×v T ×(E exp -E DFT ).

[0059] S4. Correct the theoretically calculated value based on the optimal energy correction value to obtain the corrected gas phase molecule energy. The corrected gas phase molecule energy can be used for theoretical calculations of other gas phase molecule properties such as enthalpy change.

[0060] To demonstrate the advantages of the method of this invention, comparisons were made with commonly used methods in the literature that use the energies of atoms C, H, O, and N as a reference for correction; methods that use the energies of common stable molecules CO2, H2, H2O, and N2 as a reference for correction; and methods that use the energies of common stable molecules CH4, H2, H2O, and N2 as a reference for correction. The energy correction results are shown in Table 2. E1 represents the gas phase molecule energy correction value obtained using the method of this invention; E2 represents the gas phase molecule energy correction value obtained using the energies of C, H, O, and N as a reference; E3 represents the gas phase molecule energy correction value obtained using the energies of CO2, H2, H2O, and N2 as a reference; and E4 represents the gas phase molecule energy correction value obtained using the energies of CH4, H2, H2O, and N2 as a reference.

[0061] Table 2

[0062] <![CDATA[H2]]> 0.01 -0.24 0.00 0.00 <![CDATA[O2]]> 0.07 0.88 0.33 0.33 <![CDATA[N2]]> -0.37 0.38 0.00 0.00 <![CDATA[H2O]]> -0.12 0.03 0.00 0.00 <![CDATA[NH3]]> -0.04 -0.04 0.13 0.13 NO -0.19 0.59 0.13 0.13 <![CDATA[N2O]]> 0.29 1.45 0.79 0.79 <![CDATA[NO2]]> 0.38 1.57 0.83 0.83 <![CDATA[CH2O]]> -0.05 0.40 0.26 0.00 <![CDATA[CH4]]> 0.15 -0.06 0.32 0.06 CO -0.32 0.39 0.00 -0.26 <![CDATA[CO2]]> -0.07 1.05 0.39 0.13 <![CDATA[CH3OH]]> -0.02 0.18 0.28 0.02 <![CDATA[C2H2O]]> 0.24 1.00 0.75 0.23 <![CDATA[CH2O2]]> -0.18 0.68 0.27 0.01 <![CDATA[H2O2]]> -0.12 0.44 0.14 0.14

[0063] From Table 2 and Figure 2 It can be seen that using commonly used atoms as reference states results in the worst performance, with a very wide distribution of gas phase molecular energy correction values, ranging from -0.8 to 1.8 eV, and an average correction value of around 0.7 eV. Using commonly used stable molecules as reference states is the next best, with a relatively concentrated distribution of gas phase molecular energy correction values, but some molecules still have relatively large correction values. Table 2 shows that although the correction value for the reference state molecules is 0, some molecules exhibit very large correction values ​​(such as N₂O in E₃ at 0.79 eV and NH₃ in E₄ at 0.83 eV), leading to a situation where some values ​​are not fully corrected. Compared to correction methods in the literature that use commonly used atoms or stable molecules as reference states, the gas phase molecular energy correction values ​​obtained using the method of this invention are more concentrated and smaller, with the correction values ​​all concentrated around 0. Therefore, using the method of this invention for correction will not affect the original properties of gas phase molecules due to large correction values.

[0064] The reaction cycle, experimental enthalpy change, theoretically calculated enthalpy change, and enthalpy change correction values ​​are shown in Table 3.

[0065] Table 3

[0066]

[0067]

[0068] As can be seen from Table 3, the theoretically calculated enthalpy change is completely consistent with the experimental enthalpy change after being corrected by the method of this invention. This indicates that the energy correction method based on the constrained least squares method for calculating gas-phase molecular theory can accurately correct the reaction enthalpy change, and the enthalpy change correction values ​​are all concentrated around 0.

[0069] If the above methods are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this invention, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0070] In other embodiments, a theoretical calculation and correction device for gas-phase molecular energy based on constrained least squares method is also provided, including a data collection module, an equation construction module, a fitting optimization module, and a correction module. The data collection module is used to acquire experimentally measured and theoretically calculated values ​​of the energy of each gas-phase molecule in the current gas-phase molecular system, constructing a gas-phase molecular energy dataset. The equation construction module is used to establish a system of linear equations for energy differences based on the gas-phase molecular energy dataset. The fitting optimization module is used to optimize and fit the system of linear equations for energy differences using constrained least squares method to obtain the optimal energy correction value. The correction module is used to correct the theoretically calculated value based on the optimal energy correction value.

[0071] In other embodiments, a gas phase molecular energy theory calculation correction device based on constrained least squares is also provided, including one or more processors, a memory, and one or more programs stored in the memory, said one or more programs including instructions for executing the gas phase molecular energy theory calculation correction method based on constrained least squares as described above.

[0072] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for correcting theoretical calculations of gas-phase molecular energy based on constrained least squares, characterized in that, Includes the following steps: Obtain experimental measurements and theoretical calculations of the energy of each gas phase molecule in the current gas phase molecular system, and construct a gas phase molecular energy dataset; A set of linear equations for energy differences was established based on the aforementioned gas phase molecular energy dataset. The energy difference linear equations are optimized and fitted using the constrained least squares method to obtain the optimal energy correction value. The theoretically calculated value is corrected based on the optimal energy correction value; The establishment of the linear equation system for the energy difference model is specifically as follows: Based on the molecular formula of the reactant molecule, the reactant molecule material matrix Mchem; Establish the material conservation equation Mchem T ×v=0, where v is the reaction cycle basis vector; By adding a correction term to the theoretical calculations, a system of linear equations for energy difference is established: v T ×E exp =v T ×(E DFT +E x ) Among them, E exp Expressed as experimental values ​​of gas-phase molecular energy, E DFT Expressed as the theoretical value of gas phase molecular energy, E x Expressed as gas phase molecular energy correction value; When optimizing the linear equations of energy difference using the constrained least squares method, the objective function is to optimize the gas phase molecule energy correction value E. x To minimize the sum of squares, the constraint condition is expressed as v. T ×E x = b, where b = v T ×(E exp -E DFT ).

2. The method for correcting theoretical calculations of gas-phase molecular energy based on constrained least squares as described in claim 1, characterized in that, The theoretical values ​​were obtained based on density functional theory.

3. The method for correcting theoretical calculations of gas-phase molecular energy based on constrained least squares as described in claim 2, characterized in that, When calculating the theoretically calculated values ​​based on density functional theory, zero-point energy correction is considered.

4. The method for correcting theoretical calculations of gas-phase molecular energy based on constrained least squares as described in claim 1, characterized in that, The reaction molecular material matrix Mchem is an n×m matrix, where n represents the type of reaction molecule and m represents the type of element.

5. The method for correcting theoretical calculations of gas-phase molecular energy based on constrained least squares as described in claim 1, characterized in that, The reaction cycle basis vector v is obtained by solving the material conservation equation using linear algebra.

6. A calibration device for theoretical calculation of gas-phase molecular energy based on constrained least squares method, characterized in that, include: The data collection module is used to acquire experimental measurements and theoretical calculations of the energy of each gas phase molecule in the current gas phase molecular system, and to construct a gas phase molecule energy dataset. An equation construction module is used to establish a set of linear equations for energy differences based on the gas phase molecular energy dataset. The fitting optimization module is used to optimize and fit the linear equations of the energy difference using the constrained least squares method to obtain the optimal energy correction value. The correction module is used to correct the theoretically calculated value based on the optimal energy correction value; The establishment of the linear equation system for the energy difference model is specifically as follows: Based on the molecular formula of the reactant molecule, the reactant molecule material matrix Mchem; Establish the material conservation equation Mchem T ×v=0, where v is the reaction cycle basis vector; By adding a correction term to the theoretical calculations, a system of linear equations for energy difference is established: v T ×E exp =v T ×(E DFT +E x ) Among them, E exp Expressed as experimental values ​​of gas-phase molecular energy, E DFT Expressed as the theoretical value of gas phase molecular energy, E x Expressed as gas phase molecular energy correction value; When optimizing the linear equations of energy difference using the constrained least squares method, the objective function is to optimize the gas phase molecule energy correction value E. x To minimize the sum of squares, the constraint condition is expressed as v. T ×E x = b, where b = v T ×(E exp -E DFT ).

7. A calibration device for theoretical calculation of gas-phase molecular energy based on constrained least squares method, characterized in that, It includes one or more processors, a memory, and one or more programs stored in the memory, said one or more programs including instructions for executing the gas phase molecular energy theory calculation correction method based on the constrained least squares method as described in any one of claims 1-5.

8. A computer-readable storage medium, characterized in that, Includes one or more programs executable by one or more processors of an electronic device, the one or more programs including instructions for performing the gas phase molecular energy theory calculation correction method based on the constrained least squares method as described in any one of claims 1-5.

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