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Title: Synergy between pair coupled cluster doubles and pair density functional theory

Pair coupled cluster doubles (pCCD) has been recently studied as a method capable of accounting for static correlation with low polynomial cost. We present three combinations of pCCD with Kohn–Sham functionals of the density and on-top pair density (the probability of finding two electrons on top of each other) to add dynamic correlation to pCCD without double counting. With a negligible increase in computational cost, these pCCD+DFT blends greatly improve upon pCCD in the description of typical problems where static and dynamic correlations are both important. We argue that—as a black-box method with low scaling, size-extensivity, size-consistency, and a simple quasidiagonal two-particle density matrix—pCCD is an excellent match for pair density functionals in this type of fusion of multireference wavefunctions with DFT.
Authors:
;  [1] ;  [2] ;  [2] ;  [3]
  1. Department of Chemistry, Rice University, Houston, Texas 77251-1892 (United States)
  2. Department of Chemistry and Department of Physics and Astronomy, Rice University, Houston, Texas 77251-1892 (United States)
  3. (Saudi Arabia)
Publication Date:
OSTI Identifier:
22416036
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 142; Journal Issue: 4; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CORRELATIONS; DENSITY FUNCTIONAL METHOD; DENSITY MATRIX; ELECTRONS; FUNCTIONALS; POLYNOMIALS; PROBABILITY; WAVE FUNCTIONS