Molecular dynamics study of diffusion of heavy water in normal water at different temperatures

Abstract

In the present work we study the diffusion of heavy water in the ordinary water and their mutual diffusion coefficient. Molecular dynamics studies of a binary mixture of heavy water (SPC/HW) and ordinary water (SPC/E), at heavy water mole fraction of 0.024 have been done at different temperatures ranging from 295K to 318K. Oxygen–oxygen radial distribution functions (RDF) have been evaluated. Self-diffusion coefficients of both solvent and solute have been determined by means of mean-squared displacement (MSD) versus time curves using Einstein's diffusion relation. Darken's relation has been used for determining the mutual diffusion coefficients at the respective temperatures. The variation of the diffusion coefficients along with temperature has been analyzed. Our results agree very well with the available previously reported experimental data.