CAS SCF/CI calculations of low-lying states of SnH 2

Abstract

Complete active space MC SCF (CAS SCF) followed by full second-order CI calculations are carried out on the three lowest-lying states of SnH 2 ( 1A 1, 3B 1, 1B 1). Relativistic effective core potentials are employed for the tin atom with the outer d 10s 2p 2 shell as the valence shell. The ground state is found to be 1A 1 ( r e = 1.78 Å, θ e = 92°). The calculated properties of the 3B 1 state are, r e=1.72 Å, θ e = 119°, T e = 22.5 kcal mole ; corresponding values for the 1B 1 state are 1.75 Å, 120° and 48.5 kcal mole . These results are compared with SiH 2 and GeH 2.