Theoretical potential-energy functions and the rovibronic spectrum of the SiH + 2 Ion

Abstract

Three-dimensional potential-energy functions for the X2A1 and Ã2B1 states of SiH+2 have been derived from extensive ab initio multi-reference configuration interaction (MRCI) calculations. Spectroscopic constants have been derived from the potential-energy functions by second-order perturbation theory. The calculated values are in very good agreement with the experimental data and also provide a secure value for the Ao rotational constant for the X2A1 state. Rovibronic levels were calculated by a variational method which takes into account Renner–Teller coupling. Theoretically derived transition wavenumbers are in good agreement with experimental results.