Display options
Cite
Di Sabatino S, Berger JA, Reining L, et al. Reduced density-matrix functional theory: Correlation and spectroscopy. J Chem Phys. 2015;143(2):024108doi: 10.1063/1.4926327.
Di Sabatino, S., Berger, J. A., Reining, L., & Romaniello, P. (2015). Reduced density-matrix functional theory: Correlation and spectroscopy. The Journal of chemical physics, 143(2), 024108. https://doi.org/10.1063/1.4926327
Di Sabatino, S, et al. "Reduced density-matrix functional theory: Correlation and spectroscopy." The Journal of chemical physics vol. 143,2 (2015): 024108. doi: https://doi.org/10.1063/1.4926327
Di Sabatino S, Berger JA, Reining L, Romaniello P. Reduced density-matrix functional theory: Correlation and spectroscopy. J Chem Phys. 2015 Jul 14;143(2):024108. doi: 10.1063/1.4926327. PMID: 26178091.
Copy Download .nbib Format: NLM
Share it on

J Chem Phys. 2015 Jul 14;143(2):024108. doi: 10.1063/1.4926327.

Reduced density-matrix functional theory: Correlation and spectroscopy.

The Journal of chemical physics

S Di Sabatino, J A Berger, L Reining, P Romaniello

Affiliations

  1. Laboratoire de Physique Théorique, CNRS, IRSAMC, Université Toulouse III-Paul Sabatier, 118 Route de Narbonne, 31062 Toulouse Cedex, France and ETSF.
  2. Laboratoire de Chimie et Physique Quantiques, IRSAMC, Université Toulouse III-Paul Sabatier, CNRS, 118 Route de Narbonne, 31062 Toulouse Cedex, France and ETSF.
  3. Laboratoire des Solides Irradiés, École Polytechnique, CNRS, CEA-DSM, 91128 Palaiseau, France and ETSF.

PMID: 26178091 DOI: 10.1063/1.4926327

Abstract

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 fillings as test systems. This allows us to analyze the underlying physics and to elucidate the origin of the observed trends. For comparison, we also report the results of the GW approximation, where the self-energy functional is approximated, but no further hypothesis is made concerning the approximations of the observables. In particular, we focus on the atomic limit, where the two sites of the dimer are pulled apart and electrons localize on either site with equal probability, unless a small perturbation is present: this is the regime of strong electron correlation. In this limit, using the Hubbard dimer at 1/2 filling with or without a spin-symmetry-broken ground state allows us to explore how degeneracies and spin-symmetry breaking are treated in RDMFT. We find that, within the used approximations, neither in RDMFT nor in GW, the signature of strong correlation is present, when looking at the removal/addition energies and spectral function from the spin-singlet ground state, whereas both give the exact result for the spin-symmetry broken case. Moreover, we show how the spectroscopic properties change from one spin structure to the other.

Publication Types