Frequency moments and viscosities of liquid aluminium

Abstract

Numerical results are presented for the second and fourth frequency moments of the spectral functions of both the longitudinal and transverse current correlation functions for liquid aluminium using the interatomic potential and the static pair correlation function obtained by Schiff (1969) from molecular dynamics calculations. A memory function approach is employed to estimate the longitudinal and shear viscosities of aluminium at its melting point. The parameters appearing in the various memory functions are determined from the frequency moments of the correlation functions. The theoretical estimates of the viscosities are in good agreement with the available experimental value.