Time-correlation functions in molecular liquids studied by the mode-coupling theory based on the interaction-site model

Abstract

Numerical results for longitudinal current spectra, velocity autocorrelation functions, and diffusion coefficients of a model diatomic liquid are presented using the recently developed theory for dynamics of classical polyatomic fluids. The theory is based on the interaction-site model for molecular liquids, the projection-operator formalism, and mode-coupling theory. The effect of the inclusion of a slow contribution in memory kernels, represented by the mode-coupling expression, on the aforementioned dynamical quantities is discussed. A molecular dynamics simulation of the same system is also performed to test the accuracy of our theory, and the theoretical results are found to be in fair agreement with those obtained from the simulation.