Active-Space Pair Two-Electron Reduced Density Matrix Theory for Strong Correlation

Active-space N-representability constraints for variational two-particle reduced density matrix calculations.

The ground-state energy of a system of fermions can be calculated by minimizing a linear functional of the two-particle reduced density matrix (2-RDM) if an accurate set of N-representability conditions is applied. In this Letter we introduce a class of linear N-representability conditions based on exact calculations on a reduced active space. Unlike wave-function-based approaches, the 2-RDM me...

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...

Part I Reduced Density Matrix Functional Theory

Reduced Density Matrix Functional for Many-Electron Systems

Reduced density matrix functional theory for the case of solids is presented and a new exchange correlation functional based on a fractional power of the density matrix is introduced. We show that compared to other functionals, this produces more accurate results for finite systems. Moreover, it captures the correct band gap behavior for conventional semiconductors as well as strongly correlate...

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...