title: Scaled opposite-spin second order Møller-Plesset correlation energy: an economical electronic structure method.
abstract: A simplified approach to treating the electron correlation energy is suggested in which only the alpha-beta component of the second order Møller-Plesset energy is evaluated, and then scaled by an empirical factor which is suggested to be 1.3. This scaled opposite-spin second order energy (SOS-MP2), where MP2 is Møller-Plesset theory, yields results for relative energies and derivative properties that are statistically improved over the conventional MP2 method. Furthermore, the SOS-MP2 energy can be evaluated without the fifth order computational steps associated with MP2 theory, even without exploiting any spatial locality. A fourth order algorithm is given for evaluating the opposite spin MP2 energy using auxiliary basis expansions, and a Laplace approach, and timing comparisons are given.
authors.affiliation: Department of Chemistry, University of California, Berkeley, California 94720, USA.
authors.forename: Yousung
authors.initials: Y
authors.lastname: Jung
authors.forename: Rohini C
authors.initials: RC
authors.lastname: Lochan
authors.forename: Anthony D
authors.initials: AD
authors.lastname: Dutoi
authors.forename: Martin
authors.initials: M
authors.lastname: Head-Gordon
mesh_terms: D000465:Algorithms; D004583:Electrons; D008962:Models, Theoretical; D015394:Molecular Structure