PROJECTS

Development of a reduced-density-matrix functional theory for solids

PRINCIPAL INVESTIGATOR

Prof. Dr. Eberhard K. U. Gross Freie Universität Berlin Institut für Theoretische Physik Arnimallee 14 14195 Berlin 030/ 838-54784 030/ 838-55258 hardy@physik.fu-berlin.de

PROJECT RESEARCH ASSISTANT

ABSTRACT

In this project, functionals of the one-body reduced density matrix or, equivalently, functionals of the natural Orbitals and their occupation numbers are employed to study electronic correlations in solids. In the past period, we achieved two goals: (a) We derived a rigorous representation of the fundamental gap in the Reduced Density Matrix Functional Theory (RDMFT) and implemented it for finite systems and for systems periodic in 1 dimension, with rather encouraging results for alkali atoms, the LiH molecule and the LiH chain, (b) We developed a scheme to treat open-shell systems within RDMFT and achieved very accurate results for openshell atoms. For the coming period we have 3 goals: (i) The first is to generalize the code to 3-dimensional periodic solids, (ii) Furthermore, we want to develop a RDMFT at finite temperature to study phase transitions such as the metal-insulator transition in transit ion-metal oxides, as well as the closing of the gap with increasing temperature in semiconductors, (iii) To study metals with RDMFT we are planning to implement a Bloch (rather than Wannier) representation of the natural orbitals.

PUBLICATIONS

N. Helbig, N.N. Lathiotakis, M. Albrecht, E.K.U. Gross,
The fundamental gap in reduced density matrix functional theory
submitted to Phys. Rev. Lett.

N.N. Lathiotakis, N. Helbig, E.K.U. Gross,
Open shells in reduced-density-matrix-functional theory
submitted to Phys. Rev. A