Application of embedded atom model to the liquid metals

Abstract

The productive method of creation the inter-particle potential in Embedded Atom Model (EAM) is presented that uses directly the structure data of liquid metal near the melting point. The embedding potential is written as the power series of the difference between the effective EAM electronic density ρ and its standard value ρ0 (ρ0 is taken as 1). The mean value <ρ> = ρ0 in the standard state of a liquid (usually near the melting point). At this definition of EAM potential, the pair term in potential coincides with the effective pair potential that can be reconstructed using the pair correlation function (PCF) of liquid metal (for example with Schommers algorithm). The parameters of embedding part of potential are determined using the potential energy of liquid in the standard state, module of compression and parameters of a liquid in any extreme state (at high temperature or pressure). The method presented was applied to the creation of EAM potentials and simulations of liquid metals bismuth, gallium, mercury, rubidium, cesium, iron and iron - sulfur solutions in wide intervals of parameters, including states near the critical point (bismuth, gallium, mercury, rubidium and cesium) and at the conditions of Earth core. The accuracy of predictions of structure properties, thermodynamic properties and diffusivity is rather good. EAM potentials constructed especially for liquid metals describe their properties in wide temperature and pressure limits much better than the EAM potentials created for crystal metals. In the states typical for the shock waves tests (at very strong compression) crystal metal EAM potentials may give very erroneous pressure data.