A systematic ab initio study of the equilibrium geometry and vibrational wave numbers of bismuthine

The equilibrium structure and the harmonic and anharmonic force fields of BiH3 are determined by high-level ab initio calculations using a variety of correlation treatments, basis sets, and pseudopotentials, partly in combination with core polarization potentials. Spin-orbit effects are included by a configuration interaction treatment. This systematic study serves to establish a reliable computational protocol for such calculations and, in particular, to minimize basis set superposition errors through an improved new basis set and/or counterpoise corrections. Using the recommended procedures, the best ab initio results for the equilibrium geometry and the fundamental vibrational wave numbers are in good agreement with the available experimental data, which further supports the recent spectroscopic identification of BiH3. The ground-state total atomization energy of BiH3 is predicted to be 153.1 kcal/mol. (C) 2004 American Institute of Physics.