Theoretical Study with Rovibrational and Dipole Moment Calculation of the SiO Molecule

Abstract

Via CASSCF/MRCI and RSPT2 calculations (single and double excitation with Davidson correction) the potential energy curves of 20 electronic states in the representationof the molecule SiO have been calculated. By fitting these potential energy curves to a polynomial around the equilibrium internuclear distance r e , the harmonic frequency ω e , the rotational constant B e , and the electronic energy with respect to the ground state T e have been calculated. For the considered electronic states the permanent dipole moment μ have been plotted versus the internuclear distance r. Based on the canonical functions approach, the eigenvalues E v , the rotational constant B v and the abscissas of the turning points r min and r max have been calculated. The comparison of these values to the experimental and theoretical results available in the literature is presented. In the present work 8 higher electronic states have been studied theoretically for the first time.