Method and system for analyzing chemical change pathway of gas

Abstract

Provided are: a calculation method whereby a chemical change pathway can be analyzed in a relatively short amount of time even for a gas having a more complex molecular structure than hydrogen, oxygen, and methane and for which various elementary reactions are expected to occur; and an analysis system that uses the analysis method. The method for analyzing a chemical change pathway of a gas according to the present invention is characterized by comprising: a step for inputting information about a gas system; a step for calculating the frequency of collisions between molecules constituting the gas and determining a first time slot, which is the frequency at which a change in the number of molecules is calculated; a step for executing a molecular dynamics calculation and calculating the number of molecules on the basis of atomic coordinates data extracted for each of the first time slots; a step for calculating the amount of change in the number of molecules for each of the first time slots by using the difference in the number of molecules in each of the first time slots; a step for selecting the time slot in which the absolute value of the amount of change in the number of molecules is the largest; and a step for analyzing the chemical change pathway by extracting atomic coordinates data on the basis of a second time slot for the time slot in which the absolute value of the amount of change in the number of molecules is the largest, wherein the first time slot is larger than the second time slot.

Description

Method and Analysis System for Analyzing Chemical Reaction Path of Gas

[0001] The present invention relates to a method for analyzing the chemical reaction path of a gas and an analysis system using the analysis method.

[0002] In industrial products that utilize the properties of gases, it is important to suppress unwanted chemical changes and the like in the gas. For example, it is important to analyze the chemical reaction path in the use environment to understand the change in the properties of the gas due to chemical changes or to evaluate the safety of the products generated by chemical changes.

[0003] In recent years, due to the progress of computer simulation technology, methods for understanding the chemical changes of various materials have been developed.

[0004] For example, Patent Document 1 (WO 2016 / 133002 A1) discloses a reaction mechanism generation method including steps of performing molecular dynamics calculations for each atom constituting each molecule in a reaction system at each time step, identifying reaction molecules and generated molecules that contributed to the chemical reaction when a chemical reaction occurred in the reaction system before and after the time step, constructing an elementary reaction composed of the related reaction molecules and generated molecules based on the atomic relevance between the reaction molecules and the generated molecules, and calculating the reaction rate constant of the constructed elementary reaction. According to Patent Document 1, it is said that even when analyzing the reaction of a complex system with a large number of molecules, the reaction can be accurately analyzed.

[0005] Further, Patent Document 2 (Special Table 2004 - 519026) discloses a method for modeling the behavior of a molecule, the method including steps of selecting a model for the molecule, the model having an equation of motion for the molecule, and integrating the equation of the model using an L - stable implicit integrator with a large time step to obtain a calculation of the behavior of the molecule. According to Patent Document 2, it is said that a method for calculating the behavior or properties of a molecular system in an environment is provided.

[0006] International Publication No. 2016 / 133002, Special Table 2004 - 519026 Gazette

[0007] Y. Zhang, Y. Li, X. Zhang, S. Xiao, and J. Tang: Insights on decomposition process of c-C4F8 and c-C4F8 / N2 mixture as substitutes for SF6, ROYAL SOCIETY OPEN SCIENCE, Vol. 5, 2018, 181104. Nanami Matsuda: Fundamentals of the Kinetic Theory of Gases, Journal of the Vacuum Society of Japan, Vol. 56, 2013, pp. 199-203.

[0008] This invention aims to analyze and understand the chemical reaction pathways of gases under relatively high-temperature conditions. Under relatively high-temperature conditions, the chemical reactions of gases are characterized by (1) a low molecular number density and therefore a low frequency / probability of collisions between molecules, resulting in longer periods during which no chemical changes (e.g., decomposition or combination based on collisions between molecules) occur; on the other hand, (2) the high speed of molecular motion means that when molecules collide, one elementary reaction is completed in a very short time.

[0009] In the reaction mechanism generation method described in Patent Document 1, molecular dynamics calculations and reaction analyses are performed while dividing the time into the smallest possible intervals and gradually advancing the time. Specifically, the examples in Patent Document 1 illustrate the analysis of the chemical reaction between hydrogen molecules and oxygen molecules, and the chemical reaction between methane molecules and oxygen molecules.

[0010] However, when attempting to perform reaction analysis on gases with more complex molecular structures or elementary reactions than those described in Patent Document 1, there are concerns that the computational complexity will increase dramatically, leading to an unrealistically long computation time.

[0011] The method for modeling molecular behavior described in Patent Document 2 is characterized by its integration of the equations of motion of the molecular model using an L-stability implicit integrator over large time steps, which has the advantage of being able to track chemical reactions over relatively long periods. It also has the characteristic of being able to handle complex and large molecules.

[0012] The molecules targeted by Patent Document 2 are biomolecules and therefore have very complex molecular structures, but the temperature environment is sufficiently low (for example, around body temperature), and it takes a long time (for example, on the order of milliseconds to seconds) for the chemical reaction to complete. In other words, the calculations in Patent Document 2 do not pose a significant problem even when performed in large time increments. To put it another way, if we were to attempt to calculate and analyze the chemical reactions of gases targeted by the present invention using the technology of Patent Document 2, there is a concern that the differences in the time required for elementary reactions would be too large, making it difficult to obtain accurate calculation results.

[0013] Given the above background, when attempting to analyze and understand the chemical reaction pathways of gases that have more complex molecular structures than hydrogen, oxygen, and methane, and in which various elementary reactions are anticipated, a computational method that can efficiently reduce the amount of computation compared to conventional techniques is desired so that the calculations can be completed within a realistic / practical timeframe.

[0014] Therefore, the object of the present invention is to provide a calculation method that can analyze the chemical reaction pathway of gases having a more complex molecular structure than hydrogen, oxygen, or methane, and in which various elementary reactions are expected, in a relatively short time, and an analysis system that utilizes this analysis method.

[0015] (I) One aspect of the present invention provides a method for analyzing the chemical change pathway of a gas, comprising: a gas system information input step of inputting information about the gas system; a first time period determination step of determining a first time period which is the frequency at which the collision frequency between molecules constituting the gas is calculated using the information about the gas system and the amount of change in the number of molecules is calculated; a molecular number calculation step of performing molecular dynamics calculations based on the information about the gas system and calculating the number of molecules based on atomic coordinate data extracted for each of the first time periods; a molecular number change amount calculation step of taking the difference in the number of molecules for each of the first time periods and calculating the amount of change in the number of molecules for each of the first time periods; an analysis target time period selection step of selecting the time period in which the absolute value of the amount of change in the number of molecules is largest; and a chemical change pathway analysis step of extracting atomic coordinate data based on a second time period for the time period in which the absolute value of the amount of change in the number of molecules is largest, wherein the first time period is larger than the second time period.

[0016] The present invention allows for the following improvements and modifications to be freely combined in the above-described method (I) for analyzing the chemical change pathway of a gas according to the present invention: (i) The first time period is 10 to 5000 times the second time period. (ii) The first time period is 1 / 100 to 100 times the reciprocal of the collision frequency. (iii) The method further includes an additional chemical change pathway analysis step in which, for the time period in the molecular number change calculation step where the absolute value of the molecular number change is second largest, atomic coordinate data is extracted based on the second time period and the chemical change pathway is further analyzed. (iv) The first time period and / or the second time period are changed during the calculation based on the temperature, pressure, and molecular number change calculated during the molecular dynamics calculation in the molecular number change calculation step.

[0017] (II) Another aspect of the present invention provides a system for analyzing the chemical change pathway of a gas, the system implementing the analysis method according to the present invention described above, comprising: an input / output unit that inputs information of the gas system and the conditions for the molecular dynamics calculation and outputs calculation results and analysis results; and an arithmetic processing unit that performs the molecular dynamics calculation, the molecular number calculation, and the chemical change pathway analysis, wherein the input / output unit includes an input mechanism for inputting information of the gas system and the conditions for the molecular dynamics calculation, and an output mechanism for displaying and outputting the calculation results and the analysis results, the arithmetic processing unit includes an interface mechanism responsible for connecting with the input / output unit, a data storage mechanism having a storage area for the information of the gas system and the conditions for the molecular dynamics calculation, a storage area for an atomic / molecular database, and a storage area for the calculation results and the analysis results, and a molecular dynamics calculation mechanism for performing the molecular dynamics calculation, a molecular number calculation mechanism for performing the molecular number calculation, and a chemical change analysis mechanism for performing the chemical change pathway analysis, the system provides a system for analyzing the chemical change pathway of a gas.

[0018] According to the present invention, it is possible to provide a calculation method that can analyze the chemical reaction pathway of gases having a more complex molecular structure than hydrogen, oxygen, or methane, and in which various elementary reactions are expected, in a relatively short time, as well as an analysis system that utilizes this analysis method.

[0019] This is a flowchart illustrating an example of a method for analyzing the chemical change pathway of a gas according to the present invention. This is a schematic diagram showing an example of a simulation model. This is an example of inputting information about the gas system to be input in information input step S1. This is a diagram showing an example of the results of atomic coordinate data obtained by molecular dynamics calculation. This is an example of the number of molecules calculation step S3, and is a graph showing the relationship between the elapsed time and the number of c-C4F8 molecules based on atomic coordinate data extracted in the first time period of 10 ps, ​​obtained as a result of performing molecular dynamics calculations for a total of 1000 ps in an analysis targeting c-C4F8. This is an example of the change in the number of molecules calculation step S4, and is a graph showing the relationship between the elapsed time and the change in the number of c-C4F8 molecules. This is a schematic diagram showing the chemical change from c-C4F8 molecules to C4F8 molecules. This is a schematic diagram showing the general configuration of the analysis system according to the present invention.

[0020] Embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention is not limited to the embodiments described herein, and it is possible to combine it with prior art or improve upon it without departing from the technical spirit of the invention.

[0021] [Method for Analyzing the Chemical Reaction Pathway of Gases] The method for analyzing the chemical reaction pathway of gases according to the present invention will be explained below, using octafluorocyclobutane (c-C4F8) as an example, with reference to Non-Patent Document 1. Figure 1 is a flowchart showing an example of the method for analyzing the chemical reaction pathway of gases according to the present invention.

[0022] As shown in Figure 1, the first step is to input the gas system information (S1), which involves inputting various conditions necessary for molecular dynamics calculations (hereinafter referred to as gas system information). This gas system information includes the type of gas being tested (e.g., elemental species, number of atoms per molecule, molecular structure, etc.), ambient temperature, number of molecules, and the size of the simulation cell (size of the computational space). If necessary, the reaction force field considering interatomic interactions and the conditions under which specific chemical reactions occur are also input.

[0023] In this analysis example, the target gas type is c-C4F8, the ambient temperature is 3000 K, the number of molecules is 100, and the simulation cell size is a cube with a side length of 26.5 nm. From the ambient temperature, number of molecules, and spatial size, the pressure is 2.2 × 10⁻⁶. 5 Pa is calculated. The molecular mass was set to 200, which is the molecular weight of c-C4F8. The diameter of the c-C4F8 molecule was calculated to be 0.782 nm using commercial quantum chemistry calculation software (Gaussian, Inc., USA).

[0024] Figure 2 shows an example of a simulation model based on information about a gas system. Figure 2 is a schematic diagram illustrating an example of a simulation model. The simulation model shown in Figure 2 is an example in which 100 c-C4F8 molecules are arranged in a cube with a side length of 26.5 nm. The molecular number density is determined by the size of the simulation cell and the number of molecules. Note that Figure 2 is illustrated to make it easier to visualize an example of a gas system to be calculated, and this drawing is not essential in the present invention.

[0025] In the information input step S1, input may be made in text format as shown in Figure 3. Figure 3 shows an example of inputting information about a gas system in the information input step S1. In Figure 3, the number of atoms, element species, simulation cell size, initial coordinate information of atoms, etc., are entered.

[0026] Next, using the information of the gas system entered in the information input step S1, the collision frequency between the molecules constituting the gas is calculated, and the first time period determination step S2 is performed to determine the first time period, which is the frequency at which the change in the number of molecules is calculated. Taking the reciprocal of the calculated collision frequency gives the mean free time of the gas system in question (the average time from when one particle collides with another particle until it collides with the next particle).

[0027] An example of how to calculate collision frequency and mean free time is described below. Note that the calculation method for collision frequency and mean free time is not limited to this example.

[0028] According to Non-Patent Document 2, the average velocity v of a gas molecule is given by Equation 1 (indicated by a bar in the equation). In Equation 1, k is Boltzmann's constant, T is the temperature (unit: K), and m is the mass of the gas molecule.

[0029]

[0030] The mean free path λ of a gas molecule (the average distance traveled from the time one particle collides with another until it collides with the next particle) is given by Equation 2, where d is the diameter of the gas molecule and n is the number density of the gas molecule.

[0031]

[0032] The molecular number density n of a gas is expressed by equation 3, which is the ideal gas law, given that the pressure is p.

[0033]

[0034] The collision frequency is obtained by dividing the average velocity v by the mean free path λ. As mentioned above, the reciprocal of the collision frequency is the mean free time τ, so the mean free time τ is expressed by Equation 4.

[0035]

[0036] Based on this mean free time τ, we determine the first time zone, which is the frequency at which we perform calculations of the time change in the number of molecules.

[0037] From the perspective of ensuring calculation accuracy, it is desirable that the first time period be such that a maximum of one elementary reaction occurs within its duration. Naturally, an elementary reaction does not necessarily occur at every mean free time τ. Making the first time period too short will lead to an increase in computational complexity. Therefore, from the perspective of balancing calculation accuracy and reduction of computational complexity, it is preferable that the first time period be between 1 / 100 and 100 times the mean free time τ, and more preferably between 1 / 50 and 50 times.

[0038] In step S2, along with determining the first time period, a second time period may be determined for analyzing the detailed chemical reaction pathway. The first time period is a relatively long time based on the mean free time τ, while the second time period is a relatively short time period for analyzing the detailed chemical reaction pathway. If the second time period is too long, the analysis of elementary reactions will be insufficient. If the second time period is too short, it will lead to an increase in computational complexity / computation time.

[0039] From the viewpoint of achieving both accuracy in calculations and reduction of computational load, the second time period is preferably 1 / 10 to 1 / 5000 of the first time period, and more preferably 1 / 50 to 1 / 1000 or more. In other words, the first time period has a duration of 10 to 5000 times that of the second time period. Note that the determination of the second time period does not necessarily have to be done in step S2, but can be done until the detailed calculation and analysis of the chemical reaction pathway later on.

[0040] In the analysis example for c-C4F8 in this specification, the average free time τ = 5 × 10 2 ps was calculated, and 10 ps, which is 1 / 50 of the τ, was determined as the first time zone. Also, 10 fs, which is 1 / 1000 of the first time zone, was determined as the second time zone.

[0041] Next, a molecular number calculation step S3 is performed in which molecular dynamics calculations are executed based on the information of the gas system input in step S1 to calculate the number of molecules for each first time zone determined in step S2. More specifically, atomic coordinate data for each first time zone is derived by executing molecular dynamics calculations, and the presence or absence of a bond is determined from the distance between atoms (atoms having a bond are determined as one molecule), and the molecular species and the number of molecules for each first time zone are calculated.

[0042] As long as desired calculation results (atomic coordinate data for each first time zone, number of molecules for each first time zone) are obtained, there is no particular limitation on the method of molecular dynamics calculation. For example, LAMMPS (open source software developed by Sandia National Laboratories, U.S. Department of Energy) or the first-principles molecular dynamics method can be preferably used.

[0043] In determining the presence or absence of a bond between atoms (whether or not it constitutes a molecule) during the calculation, it is preferable to use various atom / molecule databases (DBs). There is no particular limitation on the atom / molecule DB to be used, and the atom / molecule DB conventionally used in molecular dynamics calculations can be appropriately used.

[0044] Also, when data regarding a reaction force field is required for the calculation, commercially available reactive molecular dynamics software ResxFF (MOLSSIS Co., Ltd.) or a reaction force field (machine learning potential) constructed using machine learning can be preferably used. When using the first-principles molecular dynamics method as the method of molecular dynamics calculation, parameters necessary for executing first-principles calculations are used instead of data regarding the reaction force field.

[0045] Next, a molecular number change amount calculation step S4 is performed in which the difference in the number of molecules for each first time zone calculated in step S3 is taken to calculate the amount of change in the number of molecules for each first time zone.

[0046] An example of steps S3 to S4 is presented. Figure 4 shows an example of the results of atomic coordinate data obtained from molecular dynamics calculations. As shown in Figure 4, the atomic coordinate data is data in which the ID, elemental species, coordinate information, etc. of each atom are recorded for each first time period. The number of molecules for each first time period is calculated from this atomic coordinate data.

[0047] Figure 5 is an example of the molecule number calculation step S3, and is a graph showing the relationship between elapsed time and the number of c-C4F8 molecules based on atomic coordinate data extracted in the first time period of 10 ps, ​​obtained as a result of molecular dynamics calculations totaling 1000 ps in an analysis targeting c-C4F8. As shown in Figure 5, it can be seen that the number of c-C4F8 molecules decreases with the passage of time.

[0048] Figure 6 is an example of step S4 for calculating the change in the number of molecules, and is a graph showing the relationship between elapsed time and the change in the number of c-C4F8 molecules (Δ(c-C4F8)). As shown in Figure 6, it can be seen that there is a mixture of regions where there is no change in the number of molecules ("Δ(c-C4F8) = 0") and regions where the number of molecules is changing ("Δ(c-C4F8) ≠ 0").

[0049] "Δ(c-C4F8)=0" is considered to be a period in which virtually no chemical change occurs, while "Δ(c-C4F8)≠0" is considered to be a period in which some kind of chemical change occurs. The analytical method of the present invention differs from the conventional technique in that it performs detailed reaction analysis only in the region of "Δ(c-C4F8)≠0", and has the advantage of significantly reducing the amount of computation and computation time by not performing detailed reaction analysis in the region of "Δ(c-C4F8)=0".

[0050] Next, based on the relationship between the elapsed time and the change in the number of molecules calculated in step S4, step S5 is performed to select the time period for analysis that has the largest absolute value of the change in the number of molecules to be analyzed in detail. By performing a detailed reaction analysis on the time period with the largest increase or decrease in the region of "Δ(c-C4F8)≠0" (in other words, the time period with the largest absolute value of the change in the number of molecules), the overall picture of the chemical change can be grasped most efficiently.

[0051] Next, a chemical reaction pathway analysis step S6 is performed, in which molecular dynamics calculations are performed based on the second time period for the time period with the largest absolute value of the change in the number of molecules selected in step S5, and the chemical reaction pathway is analyzed.

[0052] In the analysis example for c-C4F8 described herein, the chemical reaction pathway was analyzed at the second time period of 10 fs relative to the time period with the largest absolute value of the change in the number of molecules shown in Figure 6 (the time period with an elapsed time of 580-590 ps). As a result, as shown in Figure 7, it was found that the "CC bond" of the c-C4F8 molecule is cleaved and ring-opened, resulting in a chemical change to a C4F8 molecule. Figure 7 is a schematic diagram showing the chemical change from a c-C4F8 molecule to a C4F8 molecule.

[0053] Next, step S7 is performed to output the obtained analysis results. There are no particular limitations on the output method; output may be displayed on a monitor or printed on paper using a printer. There are also no particular limitations on the output format of the analysis results; it may be a text representation of the molecular formula only, or it may be a representation using SMIILES notation (Simplified Molecular Input Line Entry System). SMIILES notation has the advantage of being able to distinguish between structural isomers.

[0054] In the technology described in Patent Document 1, if we set the time step to 10 fs and attempt to perform analysis for a total time of 1000 ps, ​​the total time required will be 10 5 This requires multiple reaction analyses. In contrast, in the above-described analysis example, 100 analyses were performed in the first time period and 1000 analyses in the second time period for a total analysis time of 1000 ps, ​​resulting in a total of 1100 reaction analyses. In other words, the analysis method of the present invention can reduce the amount of computation required for reaction analysis to 11 / 1000 compared to the technology of Patent Document 1.

[0055] In the analysis example above, only the c-C4F8 molecule was explained for the sake of simplicity and ease of understanding. However, when we performed a detailed analysis of other products resulting from decomposition and combination, we were able to analyze and extract the following 11 chemical changes in addition to "c-C4F8 → C4F8": "C4F8 → 2C2F4", "C4F8 → C4F7 + F", "C4F8 → C3F5 + CF3", "C4F8 → C3F6 + CF2", "C4F7 → C3F6 + CF", "C4F7 → C4F6 + F", "C3F4 → C3F3 + F", "C3F3 → C2F2 + CF", "C2F4 → C2F3 + F", "C2F3 → C2F2 + F", and "CF3 + F → CF4".

[0056] After performing a detailed reaction analysis for the time period with the largest absolute value of the change in the number of molecules, if there is sufficient computational resources / time and / or if you wish to analyze a more detailed chemical reaction pathway, you may perform an additional detailed analysis for the time period with the second largest absolute value of the change in the number of molecules. If necessary, you may also perform an additional detailed analysis for the time periods with the third and subsequent largest absolute values ​​of the change in the number of molecules.

[0057] Furthermore, if the chemical change of the target gas is mainly decomposition, the number density of molecules (i.e., pressure) increases as the chemical change progresses, and the mean free time τ decreases. On the other hand, if the chemical change of the target gas is mainly combination, the number density / pressure ratio decreases as the chemical change progresses, and the mean free time τ increases. In cases where there are large fluctuations in the mean free time τ as the chemical change progresses, the first time zone and / or the second time zone may be changed during the molecular dynamics calculation.

[0058] [Analysis System Using the Analysis Method of the Present Invention] Figure 8 is a schematic diagram showing the general configuration of the analysis system according to the present invention. As shown in Figure 8, the analysis system 100 of the present invention is a system that performs the aforementioned analysis method of the chemical change pathway of a gas, and broadly comprises an input / output unit 10 that inputs information on the target gas system and calculation conditions such as the first / second time zone and outputs calculation results and analysis results, and an arithmetic processing unit 20 that performs calculation processing such as molecular dynamics calculation, molecular number calculation and chemical change pathway analysis. The input / output unit 10 and the arithmetic processing unit 20 are interconnected.

[0059] The analysis system 100 may be connected to an external server 40 via a network 30. Furthermore, the analysis system 100 may be configured to be controllable by input / output devices (not shown) connected to the network 30 or the server 40.

[0060] The following provides a more detailed explanation of the internal structure of each part.

[0061] The input / output unit 10 includes an input mechanism 11 for inputting information about the target gas system and calculation conditions such as the first / second time zone, and an output mechanism 12 for displaying and outputting the input content, calculation results, and analysis results. There are no particular limitations on the configuration of the input mechanism 11 and the output mechanism 12, as long as the required inputs and desired outputs can be provided, and conventional input / output devices (e.g., mouse, keyboard, touch panel, display, printer, etc.) can be used as appropriate.

[0062] The arithmetic processing unit 20 includes an interconnected interface (I / F) mechanism 21, a data storage mechanism 22, and an arithmetic processing mechanism 23. The I / F mechanism 21 is responsible for connecting to the input / output unit 10 and / or the network 30. There are no particular limitations on the configuration of the I / F mechanism 21, and conventional interface standard components can be used as appropriate.

[0063] The data storage mechanism 22 has a storage area 221 for information on the gas system and calculation conditions input from the input mechanism 11 of the input / output unit 10, a storage area 222 for the atom / molecule DB, a storage area 223 for the force field DB, and a storage area 224 for calculation results and analysis results performed by the arithmetic processing mechanism 23. The data storage mechanism 22 is not particularly limited as long as it can store the necessary data, and conventional data storage devices (e.g., random access memory (RAM), hard disk drive (HDD), solid state drive (SSD), etc.) can be used as appropriate.

[0064] The computational processing mechanism 23 includes a molecular dynamics calculation mechanism 231, a molecular number calculation mechanism 232, and a chemical change analysis mechanism 234. These mechanisms 231 to 234 work together with each other and with the data storage mechanism 22 to perform steps S2 to S6 of the analysis method of the present invention. The computational processing mechanism 23 is not particularly limited as long as it can perform the various calculations desired, and conventional computational processing units (e.g., central processing unit (CPU), graphics processing unit (GPU), random access memory (RAM), read-only memory (ROM), etc.) can be used as appropriate.

[0065] The embodiments described above are explained to aid in understanding the present invention, and the present invention is not limited to the specific configurations described. For example, it is possible to replace some of the configurations of the embodiments with configurations that are common knowledge to those skilled in the art, and it is also possible to add configurations that are common knowledge to those skilled in the art to the configurations of the embodiments. In other words, the present invention allows for deletion, substitution with other configurations, and addition of other configurations to some of the configurations of the embodiments specified herein, without departing from the technical spirit of the invention.

[0066] 100...Analysis system, 10...Input / Output unit, 11...Input mechanism, 12...Output mechanism, 20...Calculation processing unit, 21...I / F mechanism, 22...Data storage mechanism, 221...Storage area for gas system information and calculation conditions, 222...Atomic / molecular DB storage area, 223...Force field DB storage area, 224...Storage area for calculation results and analysis results, 23...Calculation processing mechanism, 231...Molecular dynamics calculation mechanism, 232...Molecular number calculation mechanism, 234...Chemical change analysis mechanism, 30...Network, 40...Server.

Claims

1. A method for analyzing the chemical change pathway of a gas, comprising: a gas system information input step of inputting information about the gas system; a first time period determination step of determining a first time period which is the frequency at which the collision frequency between molecules constituting the gas is calculated using the information about the gas system and the amount of change in the number of molecules is calculated; a molecular number calculation step of performing molecular dynamics calculations based on the information about the gas system and calculating the number of molecules based on atomic coordinate data extracted for each of the first time periods; a molecular number change amount calculation step of taking the difference in the number of molecules for each of the first time periods and calculating the amount of change in the number of molecules for each of the first time periods; an analysis target time period selection step of selecting the time period in which the absolute value of the amount of change in the number of molecules is largest; and a chemical change pathway analysis step of extracting atomic coordinate data based on a second time period for the time period in which the absolute value of the amount of change in the number of molecules is largest, wherein the first time period is larger than the second time period.

2. A method for analyzing the chemical change pathway of a gas according to claim 1, characterized in that the first time period is 10 times or more and 5000 times or less than the second time period.

3. A method for analyzing the chemical change pathway of a gas according to claim 1, characterized in that the first time period is 1 / 100 times or more and 100 times or less the reciprocal of the collision frequency.

4. A method for analyzing the chemical change pathway of a gas according to claim 2, characterized in that the first time period is 1 / 100 times or more and 100 times or less the reciprocal of the collision frequency.

5. A method for analyzing the chemical change pathway of a gas according to claim 1, further comprising an additional chemical change pathway analysis step, in which atomic coordinate data is extracted based on the second time period and the chemical change pathway is further analyzed for the time period in which the absolute value of the change in the number of molecules in the calculation step of the change in the number of molecules is second largest.

6. A method for analyzing the chemical change pathway of a gas according to claim 2, further comprising an additional chemical change pathway analysis step, in which atomic coordinate data is extracted based on the second time period and the chemical change pathway is further analyzed for the time period in which the absolute value of the change in the number of molecules in the calculation step of the change in the number of molecules is second largest.

7. A method for analyzing the chemical change pathway of a gas according to claim 3, further comprising an additional chemical change pathway analysis step, in which atomic coordinate data is extracted based on the second time period and the chemical change pathway is further analyzed for the time period in which the absolute value of the change in the number of molecules in the calculation step of the change in the number of molecules is second largest.

8. A method for analyzing the chemical change pathway of a gas according to claim 4, further comprising an additional chemical change pathway analysis step, in which atomic coordinate data is extracted based on the second time period and the chemical change pathway is further analyzed for the time period in which the absolute value of the change in the number of molecules in the calculation step of the change in the number of molecules is second largest.

9. A method for analyzing the chemical change pathway of a gas according to any one of claims 1 to 8, characterized in that the first time period and / or the second time period are changed during the calculation based on the temperature, pressure, and molecular number change calculated during the molecular dynamics calculation in the molecular number change calculation step.

10. A system for analyzing the chemical change pathway of a gas, wherein the system implements the analysis method described in any one of claims 1 to 8, and comprises: an input / output unit that inputs information of the gas system and the conditions for the molecular dynamics calculation and outputs calculation results and analysis results; and a calculation processing unit that performs the molecular dynamics calculation, the molecular number calculation, and the chemical change pathway analysis, wherein the input / output unit includes an input mechanism for inputting information of the gas system and the conditions for the molecular dynamics calculation, and an output mechanism for displaying and outputting the calculation results and the analysis results; and the calculation processing unit includes an interface mechanism responsible for connecting to the input / output unit; a data storage mechanism having a storage area for the information of the gas system and the conditions for the molecular dynamics calculation, a storage area for an atomic / molecular database, and a storage area for the calculation results and the analysis results; and a molecular dynamics calculation mechanism for performing the molecular dynamics calculation, a molecular number calculation mechanism for performing the molecular number calculation, and a chemical change analysis mechanism for performing the chemical change pathway analysis.

11. A system for analyzing the chemical change pathway of a gas, wherein the system implements the analysis method described in claim 9, and comprises: an input / output unit that inputs information of the gas system and the conditions for the molecular dynamics calculation and outputs calculation results and analysis results; and an arithmetic processing unit that performs the molecular dynamics calculation, the molecular number calculation, and the chemical change pathway analysis, wherein the input / output unit includes an input mechanism for inputting information of the gas system and the conditions for the molecular dynamics calculation, and an output mechanism for displaying and outputting the calculation results and the analysis results; and the arithmetic processing unit includes an interface mechanism responsible for connecting with the input / output unit; a data storage mechanism having a storage area for the information of the gas system and the conditions for the molecular dynamics calculation, a storage area for an atomic / molecular database, and a storage area for the calculation results and the analysis results; and a molecular dynamics calculation mechanism for performing the molecular dynamics calculation, a molecular number calculation mechanism for performing the molecular number calculation, and a chemical change analysis mechanism for performing the chemical change pathway analysis.

Images