主講人： Prof. Cheng-chau Chiu (Department of Chemistry, National Sun Yat-sen University)
題目：A Bit about the Theory and Application of the kinetic Monte Carlo Method
時間：111年12月29日(四) 18:00
報名網址： https://forms.gle/jtSrSW1mGXiGALUK8
報名截止時間 ：111年12月29日中午12點止
報告語言: 中文
大綱:
Traditionally, first-principles computational chemistry tends to look at chemical reactions from the perspective of energies. In other words, the starting point for investigating a chemical process is, in most cases, calculating the reaction and activation energies. However, such data are often not easy to interpret directly. Therefore, it is necessary to use thermodynamic or kinetic models to convert the computed energies into macroscopic observables. However, setting up a model that can be solved analytically is often not trivial, particularly for systems where the reactants are not evenly distributed or have non-negligible interactions. For such cases, one can use a so-called kinetic Monte Carlo (kMC) model, which models a chemical process as a series of stochastic processes. This talk will briefly discuss the theory behind the kMC method. Then, the talk will use a recent work on the migration of vacancy sites on MoS2 monolayers1 to illustrate how a (grid-based) kMC algorithm can look like. Using the same example, the talk will show that the time scales that can be simulated with a kMC model heavily depend on the rate constants of the reaction to be considered. The presence of processes with a large rate constant in the kMC model to be considered will significantly slow down the simulation. The talk will also show, how we have dealt with this issue by periodically “disabling” the fast processes in the kMC model.
References:1.P.-Y. Wang, B.-A. Chen, Y.-C. Lee, C.-c. Chiu, Phys Chem Chem Phys, 2022, 24, 24166-24172.
