Construction of a Changed Potential of Interatomic Interaction in the Case of Temperature-Accelerated Dynamics Simulation

Abstract

The temperature-accelerated dynamic simulation technique based on an increase in the temperature of a system to intensify the thermally induced motion of its atoms enables the simulation of atomic systems over time periods inaccessible by means of classical molecular dynamics simulation. The technique of changing the interaction potential within the temperature-accelerated simulation proposed in this paper is aimed at compensating thermal expansion of the system when its temperature increases and to estimate the variations of the frequencies of normal modes of system vibrations. The presented examples of the simulation of two- and three-dimensional systems show that the proposed procedure of modification of the interatomic interaction potential enables one to estimate times of atomic-system transitions between states during temperature- accelerated simulation close to the data provided by classical molecular dynamics simulation. Additionally, modification of the interatomic interaction allows one to improve the accuracy of estimations of the transition probabilities at temperature-accelerated simulation, which increases the reliability of the description of nanoatomic-system evolution.