Study On The Dynamic Process And Physical Properties Of Bimetallic Clusters

In the research of condensed matter physics system,the research of clusters involves a lot of research directions,such as materials,quantum chemistry and life sciences.With the development of computer technology and the increasing level of computational simulation and methods,a series of significant results have been achieved through computational simulation.The research methods of computational simulation are increasingly drawing attention from researchers.At present,the first-principles based density functional theory?DFT?method and molecular dynamics?MD?method become the two mainstream methods in the field of computing.The research content of this paper consists of two parts.The first part of the research content is to write the molecular dynamics program based on Gupta potential?semi-empirical potential?for the bimetallic clusters through Fortran computer programming language.The program has the function of relaxation,cooling and warming of the cluster.In order to improve the simulation efficiency of the program,the cell list method was added to the program.And the program has been expanded into a Fortran program for trimetal clusters;The second part of the research content is to use the first-principle molecular dynamics quenching technique to perform global ground state search on Pt₁₃3 clusters by using the first-principles VASP program package combined with Python scripting language tools.The main conclusions of the paper are as follows:?1?In order to verify the correctness of the program,we simulated the melting behaviors of the pure clusters Co₁₃,Co₅₅,Co₁₄₇,and the mixed cluster Ag₅₅Cu₂₅₄.We calculated the specific heat of the cluster C_v and the Lindemann Index of the cluster to determine the cluster's the melting point,the simulation results are basically consistent with the results already published.?2?Using the I_h structure of Pt₁₃3 as the initial structure to carry out the warming simulation with a temperature interval of 200K.The temperature was increased from T=200 K to T=2000 K.100 structures were extracted from 2000 ion steps at each temperature point for quenching.The calculation results show that the ground state structure of Pt₁₃3 can be found more efficiently in the temperature range of 400K-800K?the pre-melting range of the cluster?.The first-principle molecular dynamics quenching technique provides a new way to find the ground state of small clusters,especially for the searching the ground state of small mixed clusters?e.g.,the small bimetallic clusters?.