Theoretical study of the electronic spectrum of the SiC- anion

Abstract

The potential energy curves of the X(2)Sigma(+), A(2)II, and B(2)Sigma(+) states of the SiC- anion and of the (XII)-I-3 state of SiC have been calculated at the internally contracted multireference configuration interaction (CMRCI) level with Dunning's augmented correlation-consistent polarized valence quadruple-zeta(-) (aug-cc-pVQZ) basis set. The equilibrium bond lengths (r(e)), harmonic frequencies (omega(e)), first-order anharmonicity constants (omega(e)x(e)), rotational constants (B-e), dipole moments (mu(e)), and dissociation (D-e) and excitation (T-e) energies for these states have been calculated. Core-correlation effects have been studied on both the X(2)Sigma(+) ground state and first excited A(2)II State of SiC-. The spectroscopic constants of the A(2)II and B(2)Sigma(+) states of SiC- and of the (XII)-I-3 state of SiC are in good agreement with available experimental data. Adiabatic and vertical electron affinities (EA) of SiC((XII)-I-3) have also been computed at the CMRCI/aug-cc-pVQZ level. The electronic transition moment functions (ETMFs) for both the B(2)Sigma(+)-(XC+)-C-2 and B(2)Sigma(+)-A(2)II transitions have been calculated at the CMRCI/aug-cc-pVQZ level. Based on both the calculated potential energy curves and the transition moments, the radiative lifetimes of the B(2)Sigma(+)(v'=0-10) states have been computed.