| Abstract: | Abstract Computer simulations of the motion of vacancies in a Lennard-Jones model of solid argon have been made by the molecular dynamics technique. The results have been used to evaluate and analyse the heat of transport parameter Q*v for vacancies in this substance. At a temperature of 30 K it is found to be -12 kJ mol-1. The theory of transport shows that there are three main contributions to this quantity coming from the fluxes of kinetic energy, potential energy and a virial of the forces related to the local stress tensor. The main contribution to Q*v is found to be that from the virial term. This explains why discussions that aim to relate the heat of transport to the corresponding enthalpy of activation (which is almost entirely potential energy) have not been successful. |
