Structure and dynamics of liquid Zn: an analysis of ab-initio simulations

The static and dynamic properties of liquid Zn have been studied using an ab initio molecular dynamics method. Results are reported for the thermodynamic states at 723K near which inelastic neutron and x-ray scattering data are available. The calculated static structure shows very good agreement with experimental measurements, including an asymmetric main peak. The dynamic structure reveals the existence of propagating density fluctuations, and the associated dispersion relation has also been calculated. The possible coupling between longitudinal and transverse excitation modes has been investigated by looking at specific signatures in two wavevector regions: the first one is located around the position of the main peak of the structure factor, q(p), as suggested by the recently reported appearance of high frequency transverse waves in several liquid metals under high pressures; the second region is around q(P)/2, as suggested by inelastic scattering experiments for liquid Zn and other metals.