Self-consistent RPA and the time-dependent density matrix approach

Occupation numbers in Self Consistent RPA

A method is proposed which allows to calculate within the SCRPA theory the occupation numbers via the single particle Green function. This scheme complies with the Hugenholtz van Hove theorem. In an application to the Lipkin model it is found that this prescription gives consistently better results than two other commonly used approximations: lowest order boson expansion and the number operator...

Self-consistent Green’s function and RPA studies of nuclei

where E PT is the contribution to the total binding energy in second order perturbation theory. A perturbative expansion of the RPA equations shows that (i) the sum in Eq. (1) must also include charge exchange modes and (ii) E PT is double counted and must be subtracted [3]. This leads to an improved description of the binding energies of most closed shell nuclei, up to Pb, as shown in Fig. 1 [...

The Density Matrix Renormalization Group and its time-dependent variants

Since its creation in 1992, the density matrix renormalization group (DMRG) method [1] has evolved and mutated. From its original formulation in a condensed matter context, it has been adapted to study problems in verious fields, such as nuclear physics and quantum chemistry, to become one of the dominant numerical methods to study strongly correlated systems. The purpose of these lectures is t...

Localized-density-matrix implementation of time-dependent density-functional theory

Self-consistent embedding of density-matrix renormalization group wavefunctions in a density functional environment.

We present the first implementation of a density matrix renormalization group algorithm embedded in an environment described by density functional theory. The frozen density embedding scheme is used with a freeze-and-thaw strategy for a self-consistent polarization of the orbital-optimized wavefunction and the environmental densities with respect to each other.