Static correlated functionals for reduced density matrix functional theory

Part I Reduced Density Matrix Functional Theory

Size consistency of explicit functionals of the natural orbitals in reduced density matrix functional theory.

We report a size-inconsistency problem for several functionals within reduced density matrix functional theory. Being explicit functionals of the natural orbitals and occupation numbers, instead of the one-body reduced density matrix, many of the approximate functionals are not invariant under unitary transformations in the subspace of degenerate occupation numbers. One such transformation mixe...

Local reduced-density-matrix-functional theory: Incorporating static correlation effects in Kohn-Sham equations

Nektarios N. Lathiotakis,1 Nicole Helbig,2 Angel Rubio,3 and Nikitas I. Gidopoulos4 1Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Vass. Constantinou 48, GR-11635 Athens, Greece 2Peter-Grünberg Institut and Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich, Germany 3Nano-Bio Spectroscopy Group and ETSF Scientific Development Centr...

Avoiding the 4-index transformation in one-body reduced density matrix functional calculations for separable functionals.

One of the major computational bottlenecks in one-body reduced density matrix (1RDM) functional theory is the evaluation of approximate 1RDM functionals and their derivatives. The reason is that more advanced approximate functionals are almost exclusively defined in the natural orbital basis, so a 4-index transformation of the two-electron integrals appears to be unavoidable. I will show that t...

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...