On the isolation of possible artifacts due to cubic periodic boundary conditions

Abstract

Cubic periodic boundary conditions in computer simulations of molecular dynamics may produce artifacts due to imposed O h symmetry. In this communication, group theoretical statistical mechanics is used to isolate ensemble averages which exist under O h symmetry but vanish under the R h(3) symmetry of an ensemble of molecules or atoms at thermodynamic equilibrium. These are artifacts of cubic periodic boundary conditions. This method allows a check on the validity of molecular dynamics computer simulations.