Structure and self-diffusion of liquid germanium studied by a first-principles molecular-dynamics simulation

Dynamic structures of liquid germanium at the temperature of 1253 K were investigated by a long-time (66 ps) first-principles molecular-dynamics simulation. The calculated structure factor is in good agreement with the diffraction experiments. It is found that an atom diffuses quickly not only when its coordination number becomes smaller but also when surrounding atoms are moving together in almost the same direction. Moreover we found out that each atom migrates while staying in a group of several neighboring atoms for 0.3-0.5 ps. The calculated dynamic structure factors and the dispersion relation are in excellent agreement with the result of a recent X-ray inelastic scattering experiment. (C) 2002 Elsevier Science B.V. All rights reserved.