Fractional spin in reduced density-matrix functional theory

Part I Reduced Density Matrix Functional Theory

Generalized Pauli constraints in reduced density matrix functional theory.

Functionals of the one-body reduced density matrix (1-RDM) are routinely minimized under Coleman's ensemble N-representability conditions. Recently, the topic of pure-state N-representability conditions, also known as generalized Pauli constraints, received increased attention following the discovery of a systematic way to derive them for any number of electrons and any finite dimensionality of...

Noncollinear spin-spiral phase for the uniform electron gas within reduced-density-matrix-functional theory

F. G. Eich,1,2,3,* S. Kurth,4,5,3 C. R. Proetto,2,3,† S. Sharma,1,3 and E. K. U. Gross1,3 1Max-Planck-Institut für Mikrostrukturphysik, Weinberg 2, D-06120 Halle, Germany 2Institut für Theoretische Physik, Freie Universität Berlin, Arnimallee 14, D-14195 Berlin, Germany 3European Theoretical Spectroscopy Facility (ETSF) 4Nano-Bio Spectroscopy Group, Depto. de Física de Materiales, Universidad d...

Reduced density-matrix functional theory: Correlation and spectroscopy.

In this work, we explore the performance of approximations to electron correlation in reduced density-matrix functional theory (RDMFT) and of approximations to the observables calculated within this theory. Our analysis focuses on the calculation of total energies, occupation numbers, removal/addition energies, and spectral functions. We use the exactly solvable Hubbard dimer at 1/4 and 1/2 fil...

From Density Functional Theory to Density Matrix Functional Theory

Coupled cluster methods are considered among the most accurate tools in electronic structure theory. Nonetheless relatively limited attempt seems to have been made to extend their applicability to the description of the core-excitation phenomena that are behind largely used spectroscopic techniques like x-ray absorption spectroscopy and x-ray circular dichroism. As a first step to redeem for su...