On applicability of embedded atom model (EAM) potentials to liquid silicon and germanium

Potentials of the embedded atom model (EAM) for liquid silicon and germanium are proposed. The potentials are calculated from diffraction data using the Schommers algorithm and presented in the form of tables and piecewise continuous polynomials. Each pairwise contribution to the potential has a form close to a hard-sphere one with a step down. The properties of liquid Si and Ge at temperatures up to 2000 K are calculated, viz. the density, energy, bulk modulus, and self-diffusion coefficients. The agreement with the experiment is noted to be good. The bond direction is found to almost completely disappear after melting for ordinary densities of liquid Si and Ge. The bond direction is assumed to be able to appear at heating and when the density of melts is decreased by 2–3 times.