On the calculation of specific heats, thermal pressure coefficients and compressibilities in molecular dynamics simulations

Abstract

Expressions are derived for the specific heat, C_v , the thermal pressure coefficient, γ _v , and the adiabatic compressibility, β _S , in terms of the fluctuations of the kinetic energies and the microscopic ‘ pressure function ’ in the microcanonical ensemble by direct extension of an analysis by Lebowitz et al. [1]. The present results apply to rigid polyatomic molecules and are tested with molecular dynamics results for a diatomic system.