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Dynamical Correlations in Liquid Metals K and Cs
Author(s) -
Jain K. C.,
Gupta Neelam,
Saxe. S.
Publication year - 1990
Publication title -
physica status solidi (b)
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.51
H-Index - 109
eISSN - 1521-3951
pISSN - 0370-1972
DOI - 10.1002/pssb.2221610119
Subject(s) - pseudopotential , mean squared displacement , physics , harmonic , displacement (psychology) , autocorrelation , spectral density , current (fluid) , correlation function (quantum field theory) , scaling , square (algebra) , atomic physics , mathematics , quantum mechanics , thermodynamics , molecular dynamics , statistics , geometry , psychology , psychotherapist
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.