Quantum molecular dynamics: Accelerating diffusion via parallel replica method.

Abstract

Parallel replica dynamics (PRD) is known to be a robust algorithm for accelerated modeling of infrequent-event processes. In this paper we apply PRD to speed up quantum molecular dynamics on the example of vacancy diffusion in aluminum. At first, in order to decrease uncertainties introduced by the acceleration technique, we investigate the effect of PRD internal parameters on its outcome and propose a method of eliminating the errors. Subsequently, the latter is used to refine the values of vacancy jump rates obtained from quantum molecular dynamics simulations. Corresponding self-diffusion coefficients nicely agree with experimental data up to the melting point including slight deviations from the Arrhenius dependence.