QUANTUM MOLECULAR-DYNAMICS SIMULATIONS OF LIQUID ALKALIS

We employ a unified molecular dynamics (MD), quantum mechanical approach to simulate the behavior of large collections of atoms at finite temperature. The nuclei are moved according to classical mechanics while the forces are computed via quantum mechanical models. Two approaches have been used: (1) the extended Huckel method, which is an approximate molecular orbital approach and (2) density functional theory based on the local density approximation and plane wave pseudopotential formulation. We compute properties from the MD trajectories of up to 4 ps duration for samples containing up to 250 atoms of lithium, sodium, and potassium. These results are compared to both previous calculations and experimental results.