Ab initio study of low-lying electronic states of the SiNN radical

Abstract

The equilibrium geometries, excitation energies, force constants and vibrational frequencies for the low-lying electronic states X ³Σ^–, ã¹Δ, Ã³Π and 1 ¹Π of the SiNN radical have been calculated at the MRSDCI level with a double-zeta plus polarization basis set. Our calculations imply that SiNN is a bonding and not a van der Waals molecule. Our calculated excitation energy for X ³Σ^–→Ã³Π and vibrational frequencies for these two states are in good agreement with experiment. Electronic transition dipole moment, oscillator strength for the óΠ→ X ³Σ^– transition, radiative lifetime for the Ã³Π state and the spin properties for the X ³Σ^– state are calculated based on the MRSDCI wavefunctions, predicting results in resonable agreement with available experimental data.