AB INITIO CALCULATION OF POTENTIAL ENERGY SURFACES AND SPECTROSCOPIC PROPERTIES OF $H_{2}S$ AND $H_{3}S^{+}$

Address of Botschwina: FB Chemie der Univers. Kaiserslautern, D-6750 Kaiserslautern, West Germany Adress of Zilch, Werner, Rosmus, and Reinsch: FB Chemie der Univ. Frankfurt, D-6000 Frankfurt, West GermanyAuthor Institution:The potential energy surface of $H_{2}S$ has been computed by CEPA using a basis set of 66 contracted Gaussion type orbitals. Vibrational term energies and wave functions are calculated variationally and the fundamental vibrational frequencies (in $cm^{-1}$) are $v_{1} = 2610(2614), v_{2} = 1202(1183)$, and $v_{3} = 2620(2628)$, where experimental values are given in parentheses. The equilibrium geometry of $H_{3}S^{+}$ is $r_{e} = 1.350 {\AA}$ and $\theta_{e} = 32.21^{\circ}$ and the barrier height to inversion amounts to $11 136 cm^{-1}$. Various spectroscopic properties of the sulfonium ion are predicted