Frequency dependent thermodynamic response functions from computer simulations

Abstract

Information about frequency dependent thermodynamic properties such as the isocoric specific heat, c ̃ V(ω), or the isobaric thermal expansion coefficient, α ̃ P(ω), is important for understanding the dynamics of supercooled liquids. A special fluctuation–dissipation (FD) theorem is developed. It establishes the connection between equilibrium fluctuations in a microcanonical ensemble and response functions of macroscopic entities upon perturbation of energy or volume. Using this theory, information of all thermodynamic response functions can be calculated from one molecular dynamics simulation.