Static, dynamic, and electronic properties of liquid gallium studied by first-principles simulation.

Abstract

First-principles molecular-dynamics simulations having a duration of 8 ps have been used to study the static, dynamic, and electronic properties of Ga at the temperatures 702 and 982 K. The simulations use the density-functional pseudopotential method and the system is maintained on the Born-Oppenheimer surface by conjugate gradients relaxation. The static structure factor and radial distribution function of the simulated system agree very closely with experimental data, but the diffusion coefficient is noticeably lower than measured values. The long simulations allow us to calculate the dynamical structure factor S(q,\ensuremath{\omega}). A sound-wave peak is clearly visible in S(q,\ensuremath{\omega}) at small wave vectors, and we present results for the dispersion curve and hence the sound velocity, which is close to the experimental value. The electronic density of states is very close to the free-electron form. Values of the electrical conductivity calculated from the Kubo-Greenwood formula are in satisfactory accord with measured data.