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MM: Metall- und Materialphysik
MM 22: Electronic Properties II
MM 22.5: Vortrag
Mittwoch, 29. März 2006, 15:00–15:15, IFW A
The highly distorted hcp lattices of Zinc and Cadmium: Comparison of different ab-initio approaches — •Beate Paulus1, Krzysztof Rosciszewski2, Priya Sony3, Ulrich Wedig4, and Martin Jansen4 — 1MPI for the Physics of complex Systems, Dresden, Germany — 2Institute of Physics, Jagellonian University, Krakow, Poland — 3Institute of Technology, Mumbai, India — 4MPI for Solid State Research, Stuttgart, Germany
Among the metallic elements crystallizing in a hexagonal closed packed structure, Zn and Cd are unusual because of the significant increase of the c/a ratio. Attempts to explain this distortion theoretically suffer from the fact that the calculated properties vary significantly with the method used. In order to investigate the peculiarities and the reliability of the different methods, ground-state properties like cohesive energy, the lattice constants and the elastic constants were calculated for Zn and Cd using the Hartree-Fock method, various density functionals and hybrid methods. In addition calculations were performed for Mg as a reference system with the ideal hcp structure. The dependence of the results on the computational methods and parameters gives further insight into the bonding mechanisms leading to the distortions in Zn and Cd and helps to judge the reliability of computed electron density maps to interpret experimental results.