Simulations of liquid semiconductors using quantum forces

We present results for the structural and electronic properties of liquid Si and Ge using ab initio molecular dynamics. The interatomic forces are calculated from ab initio pseudopotentials constructed within the local-density approximation. The simulations do not utilize fictitious electron dynamics; the system is constrained to reside on the Born-Oppenheimer surface at each step of the simulation. Langevin dynamics are used to control the temperature of the system. Predicted pair and angular correlation functions, structure factors, and self-diffusion coefficients are presented for both Si and Ge.