A STUDY ON STATISTICAL METHOD IN MOLECULAR DYNAMICS SIMULATION

摘要

The focus of the present paper is placed on the study of the statistical method in molecular dynamics simulation. Based on fractal theory a hypothesis is proposed by the present authors. It is asserted that the behavior of the random motion of molecules can be described by fractional Brownian functions, and the dimensionality of the fractional Brownian motion is determined by the image of the motion of particles. The image may be obtained either by molecular dynamics simulation or directly by experimental observation. Example is provided by using CH_4 as the working substance to do the molecular dynamics simulation with L-J 12-6 potential function. Based on the simulation results the fractional dimensionality was determined, and the corresponding fractional Brownian function acting as the probability density function of the random motion of particles was constructed. A detailed demonstration was provided to verify the validity of the hypothesis.