Berlin 2008 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 20: Electronic Properties II
MM 20.4: Vortrag
Dienstag, 26. Februar 2008, 11:00–11:15, H 0111
Quantum-chemical approach to cohesive properties of metals: Anomalous behaviour of Be. — •Elena Voloshina1, Beate Paulus2, and Hermann Stoll3 — 1Max-Planck-Institut für Physik komplexer Systeme, Nöthnitzer Straße 38, D-01187 Dresden — 2Physikalische und Theoretische Chemie, Freie Universität Berlin, Takustraße 3, D-14195 Berlin — 3Institut für Theoretische Chemie, Universität Stuttgart, Pfaffenwaldring 55, D-70569 Stuttgart
Calculations based upon the incremental scheme [1], i.e. an expansion of the total correlation energy in terms of one-body, two-body and higher-order contributions, have been performed on a variety of solids with band gaps [2]. Metals require a special treatment. Via an embedding scheme, we can force localization in metallic-like model systems and can mimic the metallic band structure within finite fragments of the solid [3]. This allows for a gradual delocalization towards the infinite crystal within the incremental scheme. Up to now we successfully applied the method to magnesium [4] and group 12 elements [5,6] where in all cases the ground-state properties agree very well with experiment.The beryllium crystal has the same hcp structure as Mg; the atoms are characterized by closed ns2 shells. At the same time Mg is almost free-electron-like whereas Be, although in general metallic, shows a lower density of states of almost entirely p character at the Fermi energy; that is the reason for the anomalous behavior of Be compared with other group 2 and 12 metals.
[1] PRB 46, 6700 (1992).
[2] Phys. Rep. 428, 1 (2006).
[3] JCP 126, 134115 (2006).
[4] PRB 75, 245117 (2007).
[5] PRB 74, 094102 (2006).
[6] PRB (in press).