DYNAMIC CORRELATIONS IN LIQUID-METALS K AND CS

The theory of single particle motion in static harmonic well approximation is employed to study the dynamical correlations in potassium and cesium at their respective melting temperatures. Computation of dynamical variables like velocity autocorrelation function, power spectrum, and mean square displacement in both, potassium and cesium are made using the effective pair potential as obtained from the Ashcroft empty core model pseudopotential. The cooperative modes of motion of atoms is described in terms of the spectral functions of longitudinal current—current correlation which are obtained through the mean square displacement. Frequency corresponding to the peak positions in longitudinal current—current correlation functions are then plotted against the wave vector transfer. The above results of dynamical variables are compared with MD results of Miranda and the results of phonon dispersion with the results of Jacucci and McDonald. Good agreement is observed in the case of potassium. Copyright © 1990 WILEY‐VCH Verlag GmbH & Co. KGaA