Pair potentials in disordered many-particle systems: A study for liquid gallium

Abstract

In this paper several methods are compared which connect the effective pair potential to the pair-correlation function. These methods are a self-consistent method using molecular dynamics, the so-called modified STLS (Singwi-Tosi-Land-Sjölander) theory, the Weeks-Chandler-Andersen approach, the Percus-Yevick theory, the hypernetted-chain approximation, and the Born-Green equation. Since the pair potential is, in general, very sensitive to small variations in the paircorrelation functions, structure data were used with sufficient accuracy in the determination of the pair potentials from the pair-correlation function. Narten performed measurements on liquid gallium with high precision, and, therefore, all calculations given in this paper have been performed on the basis of Narten's structure data. It turned out that the self-consistent method and the Weeks-Chandler-Andersen approach led to reasonable results. The results for the pair potential obtained from the other methods are unsatisfactory and cannot be used in the determination of liquidgallium properties.