Berlin 2012 – wissenschaftliches Programm
O 73: Focussed session: Frontiers of electronic structure theory: Strong correlations from first principles V (jointly with TT)
O 73.4: Vortrag
Donnerstag, 29. März 2012, 17:00–17:15, HE 101
Treatment of spin in reduced density-matrix functional theory — •Nicole Helbig1,2, Nektarios Lathiotakis3, Stefan Kurth2,4, and Angel Rubio2 — 1Peter Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich and JARA, 52425 Jülich, Germany — 2NanoBio Spectroscopy group and ETSF Scientific Development Centre, Dpto. Física de Materiales, Universidad del País Vasco, Centro de Física de Materiales CSIC-UPV/EHU-MPC and DIPC, 20018 San Sebastián, Spain — 3Theoretical and Physical Chemistry Institute, NHRF, Vass. Constantinou 48, 11635 Athens, Greece — 4IKERBASQUE, Basque Foundation for Science, 48011 Bilbao, Spain
Many currently used approximations to the exchange-correlation energy in reduced density-matrix functional theory do not satisfy the spin constancy condition. Hence, these approximations yield different energies for ensembles of degenerate spin configurations both in an ensemble approach and a direct minimization of the energy. These findings are hardly surprising since the approximations were originally derived and optimized for closed shell systems. We discuss possible extensions to open-shell and spinor functionals.