Equivalence of particle-particle random phase approximation correlation energy and ladder-coupled-cluster doubles.

Published

Journal Article

The recent proposal to determine the (exact) correlation energy based on pairing matrix fluctuations by van Aggelen et al. ["Exchange-correlation energy from pairing matrix fluctuation and the particle-particle random phase approximation," preprint arXiv:1306.4957 (2013)] revived the interest in the simplest approximation along this path: the particle-particle random phase approximation (pp-RPA). In this paper, we present an analytical connection and numerical demonstrations of the equivalence of the correlation energy from pp-RPA and ladder-coupled-cluster doubles. These two theories reduce to identical algebraic matrix equations and correlation energy expressions. The numerical examples illustrate that the correlation energy missed by pp-RPA in comparison with coupled-cluster singles and doubles is largely canceled out when considering reaction energies. This theoretical connection will be beneficial to design density functionals with strong ties to coupled-cluster theories and to study molecular properties at the pp-RPA level relying on well established coupled cluster techniques.

Full Text

Duke Authors

Cited Authors

  • Peng, D; Steinmann, SN; van Aggelen, H; Yang, W

Published Date

  • September 2013

Published In

Volume / Issue

  • 139 / 10

Start / End Page

  • 104112 -

PubMed ID

  • 24050333

Pubmed Central ID

  • 24050333

Electronic International Standard Serial Number (EISSN)

  • 1089-7690

International Standard Serial Number (ISSN)

  • 0021-9606

Digital Object Identifier (DOI)

  • 10.1063/1.4820556

Language

  • eng