Regensburg 2004 – wissenschaftliches Programm
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O: Oberflächenphysik
O 44: Elektronische Struktur (Experiment und Theorie) III
O 44.2: Vortrag
Freitag, 12. März 2004, 11:30–11:45, H38
Electronic structure of Pt3 cluster from GW theory — •Wolfgang Hübner and Yaroslav Pavlyukh — FB Physik, TU Kaiserslautern, D-67663 Kaiserslautern, Germany
The GW approximation is a powerful class of Green function approaches that allows for the improved treatment of electronic correlations. The self-consistent calculation in the framework of localized basis functions allows for the ab initio treatment of time-resolved experiments, provides corrections to the HOMO-LUMO gap, gives detailed information about the density of quasiparticle states, and describes collective excitations – plasmons. We apply our theory to a Pt3 cluster, a system with complicated electronic structure due to the open shell (d9s1) configuration of the platinum atom, the importance of the spin-orbit coupling and correlation effects. The large discrepancy between the HOMO-LUMO gap from the HF (6.3 eV) and LDA (0.48 eV) approaches indicates the necessity of using the many-body perturbation technique. Our main results for this metallic cluster are: corrections of the HOMO-LUMO gap (5.16 eV), energy resolved self-energy, and density of states. The G0W0 calculations reveal an extremely short life-time of the HOMO (70 fs) and LUMO (20 fs) states in striking agreement with the experimental observation (TR2PPE) and shows the capability of the method to treat large systems.