Atomic ordering in liquid Si and Ge by structural diffusion model calculations

A semi-empirical model for the atomic-scale structure of liquid Si and Ge has been constructed on the basis of atomic arrangements with the structure of the normal and high-pressure phases of solid Si and Ge. It has been found that liquid Si and Ge have quite similar atomic orderings, exhibiting the local tetrahedral features of the considered solid phases of Si and Ge where the features of the high-pressure phase predominate over those of the normal phase. The present model picture has been found to account well for the peculiar character of the solid-liquid phase transition in Si and Ge.