Geometry Optimization of ZnnCdm and (AlTiNi)n Clusters by the Modified Diffusion Monte Carlo Method

Abstract

General information about the problem of determining ground-state geometries of atomic clusters has been given. Modified diffusion Monte Carlo (MDMC) method which was recently developed for this problem has been reviewed. A technique, called the rotation operation, has been proposed to escape from local minima. Information about empirical potential energy functions, used in the computations, has been given. Binding energy results for ZnnCdm and (AlTiNi)n clusters obtained by the combination of the MDMC method and the rotation operation have been presented and these results have been compared with the molecular dynamics (MD) results. Efficiency of the method has been investigated by comparing the results and the computation times with the results of the single walker MDMC method - rotation operation combination.