Anharmonic force field and spectroscopic constants of silene: an ab initio study

High-level ab initio calculations with large basis sets are reported for silene, H2C = SiH2. Correlated harmonic force fields are obtained from coupled cluster CCSD(T) calculations with the cc-pVQZ basis (cc-pVTZ for H) while the anharmonic force fields are computed at the MP2/TZ2Pf level. There is excellent agreement with the available experimental data, in particular the equilibrium geometry and the fundamental vibrational frequencies. Many other spectroscopic constants are predicted for the C-2v isotopomers of silene.