Effective Pair Interactions and Structure in Liquid Noble Metals within Wills-Harrison and Bretonnet-Silbert Models

Nikolay Dubinin,Roman Ryltsev

doi:10.3390/met11071115

Abstract

Recently, for calculating the effective pair interactions in liquid transition metals, we have developed an approach which includes the Wills-Harrison and Bretonnet-Silbert models as limit cases. Here, we apply this approach to noble liquid metals. The dependencies of pair potentials and corresponding MD-simulated pair correlation functions in pure liquid Cu, Ag and Au on the portion of the non-diagonal (with respect to the magnet quantum number) d-d-electron couplings in the metal under consideration are studied. The model provides a good agreement with experimental and ab initio data for pair correlation functions, structure factors and velocity autocorrelation functions.

Highlights

At present, theoretical investigations of liquid transition metals and their alloys are being carried out intensively [1,2,3,4,5,6,7,8,9,10,11,12]
We used the LiquidLib code [46] to calculate velocity autocorrelation function (VAF, normalized on its initial value) for each metal using both the developed pair potentials and EAMs [43,44,45] and compared the results with those obtained by ab initio molecular dynamics (AIMD) [42]
We utilize the modified Wills-Harrison model, which takes into account the non-diagonal d-d-electron couplings between neighboring atoms, to generate effective pair interactions in noble metals, namely Cu, Ag, and Au

Summary

Introduction

Theoretical investigations of liquid transition metals and their alloys are being carried out intensively [1,2,3,4,5,6,7,8,9,10,11,12]. In works [21,25], only the diagonal matrix elements with respect to the magnet quantum number, m, between d states of neighboring atoms are taken into account. It is correct in the case of the rotational symmetry with axis along the interatomic distance. In [35], it was observed that in the case when all possible non-diagonal couplings are taken into account, the d-electron contribution to the WH effective pair potential vanishes and latter becomes equal to the NFE (i.e., in our case, to the BS) contribution only.

Modification of the Wills-Harrison Model

Conclusions