The diatomic dication SiC2+ in the gas phase

Abstract

The diatomic dication SiC2+ in the gas phase is studied using the state- averaged version of the CASSCF method and the state-specific MRMP per- turbation theory to recover dynamical correlation effects. Thirteen different electronic states of the dication were found and characterized, ten of them being metastable electronic states. The ground state is characterized by a 3_ electronic state. The leading configuration state functions are provided for each electronic state. For completeness, a similar study is presented both for SiC and for SiC+. The present results are in excellent agreement with results obtained by other authors. The adiabatic ionization energies of SiC+ to form SiC2+ are within a range from about 16 eV to about 19.5 eV. This finding indicates that a projectile, whose ionization energy lies within that range could be eventually used to produce the dication. Lifetimes and radiative transition dipole moments are also calculated and reported.