title: Development of a "First Principles" Water Potential with Flexible Monomers: Dimer Potential Energy Surface, VRT Spectrum, and Second Virial Coefficient.
abstract: The development of a "first principles" water potential with flexible monomers (MB-pol) for molecular simulations of water systems from gas to condensed phases is described. MB-pol is built upon the many-body expansion of the intermolecular interactions, and the specific focus of this study is on the two-body term (V2B) representing the full-dimensional intermolecular part of the water dimer potential energy surface. V2B is constructed by fitting 40,000 dimer energies calculated at the CCSD(T)/CBS level of theory and imposing the correct asymptotic behavior at long-range as predicted from "first principles". The comparison of the calculated vibration-rotation tunneling (VRT) spectrum and second virial coefficient with the corresponding experimental results demonstrates the accuracy of the MB-pol dimer potential energy surface.
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego , La Jolla, California 92093, United States.
authors.forename: Volodymyr
authors.initials: V
authors.lastname: Babin
authors.affiliation: ICG-CTMM CC 15.01, Universite Montpellier II , 34095 Montpellier, Cedex 05, France.
authors.forename: Claude
authors.initials: C
authors.lastname: Leforestier
authors.affiliation: Department of Chemistry and Biochemistry, University of California, San Diego , La Jolla, California 92093, United States.
authors.forename: Francesco
authors.initials: F
authors.lastname: Paesani