Ab InitioStudy of the Electronic Spectrum of the SiN Radical

Abstract

The potential energy curves of the SiN radical for the low-lying electronic states correlating up to the fourth dissociation channel have been calculated at the internally contracted multireference configuration interaction (CMRCI) level with Dunning's correlation-consistent polarization valence triple zeta (cc-pVTZ) basis set. The equilibrium bond length (re), harmonic frequency (ωe), first- and second-order anharmonicity constants (ωexe, ωeye), rotational constant (Be), centrifugal distortion constant (De), and rotation-vibrational and centrifugal coupling constants (αeand βe, respectively), as well as the dipole moment (μ0), excitation (Te), and dissociation energies (D0) for the 11 bound doublet statesX2Σ+,A2Π,B2Σ+,C2Π,D2Σ−,E2Δ,F2Π,G2Δ,H2Σ+,I2Φ, andJ2Π and 10 bound quartet statesa4Σ+,b4Π,c4Δ,d4Σ−,e4Σ+,f4Σ−,h4Δ,i4Σ+,j4Π, andk4Δ have been calculated at the CMRCI level with Dunning's correlation-consistent polarization valence quadruple zeta (cc-pVQZ) basis set. Our calculations imply that theD2Π andL2Π states in the literature should be reassigned asC2Π andF2Π, respectively. Where available, our results are found to be in good agreement with the experimental data.