## Ab Initio molecular dynamics simulation of liquid Ga-Ge alloys

#### R. V. Kulkarni and D. Stroud,
Department of Physics,
The Ohio State University, Columbus, Ohio 43210

We report the results of ab initio molecular dynamics simulations
of liquid Ga-Ge alloys at four different concentrations. We use the
plane-wave pseudopotential method to carry out the simulations.
The physical quantities studied include the partial structure factors,
bond-angle distributions, self-diffusion coefficients, electronic
density of states and the electrical conductivity.
The introduction of Ga causes a distinct reduction of the shoulder
in the structure factor of pure liquid Ge.
Correspondingly, the partial structure factors,
pair correlation functions, and bond angle distribution functions all show
behavior characteristic of simple liquid metals except at 80% Ge.
The electronic density of states shows behavior consistent with the structure:
it evolves from having a distinct pseudogap
at low concentrations of Ga to being almost free-electron-like for high
Ga concentrations. The calculated behaviour of the electrical conductivity
agrees qualitatively with previous calculations based on the Faber-Ziman
theory of liquid alloys. The self-diffusion coefficients D_(Ge-Ge) and
D_(Ga-Ga) are consistent with previous calculations and
available experiments for the pure liquids.