Ab Initio Study of the Electronic Spectrum of the SiN Radical

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 (omegae), first- and second-order anharmonicity constants (omegaexe, omegaeye), rotational constant (Be), centrifugal distortion constant (De), and rotation-vibrational and centrifugal coupling constants (alphae and betae, respectively), as well as the dipole moment (&mgr;0), excitation (Te), and dissociation energies (D0) for the 11 bound doublet states X2Sigma+, A2Pi, B2Sigma+, C2Pi, D2Sigma-, E2Delta, F2Pi, G2Delta, H2Sigma+, I2Phi, and J2Pi and 10 bound quartet states a4Sigma+, b4Pi, c4Delta, d4Sigma-, e4Sigma+, f4Sigma-, h4Delta, i4Sigma+, j4Pi, and k4Delta have been calculated at the CMRCI level with Dunning's correlation-consistent polarization valence quadruple zeta (cc-pVQZ) basis set. Our calculations imply that the D2Pi and L2Pi states in the literature should be reassigned as C2Pi and F2Pi, respectively. Where available, our results are found to be in good agreement with the experimental data. Copyright 1998 Academic Press.