First-principles molecular dynamics of liquid alkali metals based on the quantal hypernetted chain theory.

A first-principles molecular dynamics (MD) scheme is presented on the basis of the density-functional (DF) theory with use of the the quantal hyper-netted chain (QHNC) approximation. The DF theory brings about exact expressions for the ion-electron and ion-ion radial distribution functions (RDF’s) of an electron-ion mixture as a model of a simple liquid metal. These exact expressions prove that an ion-electron mixture can be treated as a one-component liquid interacting only via a pairwise interaction in the evaluation of the ionion RDF, and provide a set of integral equations: one is an exact integral equation for the ion-ion RDF and another for an effective ion-ion interaction, which depends on the ion configuration specified by the ion-ion RDF. Hence, after some approximations are introduced, the MD simulation can be perAuthor to whom correspondence should be addressed. E-mail: [email protected]