The electronic structure of the germyl anion GeH3−. A comparison with other AH3− species

Abstract

The electronic structure of the germyl anion, GeH3−, has been investigated by ab initio SCF calculations using large Gaussian basis sets. Various levels of basis set contraction for Ge are discussed. The optimum geometry of the ion is found to be C3V with r (Ge–H) =1.61 Å and ϑ (H–Ge–H) =95.9°. The barrier to inversion for GeH3− is 30.0 kcal/mole obtained with a (16,13,7/6,1)/[12,10,4/4,1] basis set. The inversion barrier in SiH3− was also studied and was found to be 26.0 kcal/mole. Vertical electron affinities for GeH3 and SiH3 have been determined from the negative ion wave functions using Koopmans’ theorem. The values are 1.94 eV for GeH3 and 1.65 eV for SiH3. A comparison with the experimental photodetachment results is also presented.