Ab initio potentials for (H2S)2, including studies of effects from third-order many-body perturbation theory and three-body nonadditivity

Abstract

Articles you may be interested inErratum: A b i n i t i o potentials for (H2S)2, including studies of effects from thirdorder manybody perturbation theory and threebody nonadditivity [J. Chem. Phys. 9 2, 3605 (1990)] J. Chem. Phys. 92, 6338 (1990); 10.1063/1.458610 Multipole moments, polarizabilities, and hyperpolarizabilities for N2 from fourthorder manybody perturbation theory calculations J. Chem. Phys. 88, 7623 (1988); 10.1063/1.454327Convergence studies of the effective valence shell Hamiltonian for correlation energies of the fluorine atom and its ions using third order quasidegenerate manybody perturbation theory Analysis of a b i n i t i o effective valence shell Hamiltonian calculations using third order quasidegenerate manybody perturbation theory Ab initio Hartree-Fock (HF) and many-body perturbation theory through second (E2) and third order (E3) were used to generate pair potentials for (H 2 S) 2' Several basis sets were developed by optimizing polarization functions with the zeroth-order dipole or quadrupole polarizabilities. Approximately 30 ab initio points (fully counterpoised HF + E2) in each of two larger basis sets were fit with site-site potentials. Intermediate potentials for fewer points indicate that only about 30 points are a sufficient data base to predict energies in the vicinity of the well with an accuracy of about 10%. The best ab initio well depth produced ( -0.0693 eV) lies at 94% of the only published experimental value ( -0.074 ± 0.013 eV), although arguments are presented which indicate that the true (H 2 Sh minimum may lie below -0.08 eV. The role ofE3 and nonadditive effects has also been explored, but they were found not to account for the major part of the remaining discrepancy between our best number and experiment.

Ab initio intermolecular potential energy surface and thermophysical properties of hydrogen sulfide

“…Previous ab initio studies were in most cases limited to very few selected configurations, like equilibrium structures and transition states. [6][7][8][9][10] Only Woon and Beck 11 developed two analytical site-site potentials based on fits to about 30 ab initio points each, using different basis sets at the MP2 level of theory. In molecular simulations involving hydrogen sulfide simple empirical effective pairpotentials were utilized (see for example ref.…”