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Title: Noniterative local second order Mo/ller{endash}Plesset theory: Convergence with local correlation space

We extend our noniterative local correlation method [P. E. Maslen and M. Head-Gordon, Chem. Phys. Lett., {bold 283}, 102 (1998)] by defining a hierarchy of local spaces, ranging from small to large. The accuracy of the local method is then examined as a function of the size of the local space. A medium size local space recovers 98{percent} of the MP2 correlation energy, and reproduces fine details of the potential energy surface such as rotational barriers with an RMS error of 0.2 kcal/mol and a maximum error of 0.4 kcal/mol. A large local space recovers 99.5{percent} of the correlation energy and yields rotational barriers with a RMS error of 0.05 kcal/mol and a maximum error of 0.1 kcal/mol, at significantly increased computational cost. {copyright} {ital 1998 American Institute of Physics.}
Authors:
;  [1]
  1. Department of Chemistry, University of California, Berkeley, Berkeley, California, 94720 (United States)
Publication Date:
OSTI Identifier:
298604
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 109; Journal Issue: 17; Other Information: PBD: Nov 1998
Country of Publication:
United States
Language:
English
Subject:
66 PHYSICS; PERTURBATION THEORY; ELECTRONIC STRUCTURE; MOLECULAR ORBITAL METHOD; ELECTRON CORRELATION