We present ab initio molecular-dynamics simulations for Cdx Te1-x liquids where the composition is nonstoichiometric. The simulations are performed following Born-Oppenheimer molecular dynamics. The required forces are obtained from a solution of the Kohn-Sham equation using ab initio pseudopotentials. We consider stoichiometries of the form: Cdx Te1-x, where x=0.2, 0.4, 0.6, and 0.8. For each composition of the melt, we consider a range of temperatures near the experimentally determined liquid temperatures. We examine the microstructural properties of the melt, the viscosity, and self-diffusion properties of the liquid as a function of the stoichiometry and temperature. We also perform an analysis of the distribution of the electronic density of states in these liquids. We find that structural changes in the local order, experimentally predicted to occur when the concentration of Cd is increased, are closely related to changes in the electronic properties of the melt.
Bibliographical noteFunding Information:
This work was funded in part by the National Science Foundation under DMR-0130395 and DMR-0325218, the U.S. Department of Energy under DE-FG02-89ER45391 and DE-FG02-03ER15491, and the Microgravity Sciences Program of the National Aeronautics and Space Administration. The calculations were performed at the Minnesota Supercomputing Institute and at the National Energy Research Scientific Computing Center (NERSC). One of the authors (M.M.G.A.) acknowledges support from the “Ministerio de Educación y Ciencia” of Spain under the program “Ramón y Cajal.”