Functional series in asymmetric-molecular-rotor theory. II. Second-rank tensor correlation functions and spectral densities for a free classical ensemble

This is the authors' abstract. We don't add key points for this paper.

Correlation functions of second-rank tensors for a system of freely rotating asymmetric-top molecules are given in the form of functional series. A rotation matrix is determined first with the help of a set of pseudoelliptic functions. These functions are expanded next into Fourier series. A reduced thermal average then gives the correlation functions in the form of series of integrals involving spherical-top correlation functions. The series are rapidly converging, and their Fourier transforms are presented. This development is exact and is well adapted to numerical treatment. It can be easily employed to study the extended rotational diffusion models for molecular liquids.