We present results for the structural and electronic properties of liq
uid Si and Ge using ab initio molecular dynamics. The interatomic forc
es are calculated from ab initio pseudopotentials constructed within t
he local-density approximation. The simulations do not utilize fictiti
ous 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.