title: Scaled opposite spin second order Møller-Plesset theory with improved physical description of long-range dispersion interactions.
abstract: Separate scaling of the same-spin and opposite spin contributions to the second-order Møller-Plesset energy can yield statistically improved performance for a variety of chemical problems. If only the opposite spin contribution is scaled, it is also possible to reduce the computational complexity from fifth order to fourth order in system size, with very little degradation of the results. However neither of these scaled MP2 energies recovers the full MP2 result for the dispersion energy of nonoverlapping systems. This deficiency is addressed in this work by using a distance-dependent scaling of the opposite spin correlation energy. The resulting method is compared against the previously proposed scaled MP2 methods on a range of problems involving both short and long-range interactions.
authors.affiliation: Department of Chemistry, University of California, Berkeley, USA.
authors.forename: Rohini C
authors.initials: RC
authors.lastname: Lochan
authors.forename: Yousung
authors.initials: Y
authors.lastname: Jung
authors.forename: Martin
authors.initials: M
authors.lastname: Head-Gordon
mesh_terms: D000465:Algorithms; D001128:Argon / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D019281:Dimerization; D005998:Glycine / Q000737:chemistry*; D006860:Hydrogen Bonding; D009356:Neon / Q000737:chemistry; D017433:Protein Structure, Secondary; D011789:Quantum Theory; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D009356:Neon; D001128:Argon; D005998:Glycine