Ab initio study of rovibronic energies of the CH2+ molecular ion

作者：Solomonik V G^*; Yachmenev A Yu

来源：Optics and Spectroscopy, 2008, 104(6): 818-824.

DOI：10.1134/S0030400X08060039

The potential energy surfaces of the lowest electronic states (X) over tilde (2)A(1) and (A) over tilde B-2(1) of the CH2+ molecular ion are calculated in the second order of the perturbation theory with the reference function obtained by the multiconfiguration self-consistent-field method in the complete-active-space approximation. Based on the ab initio calculated potential energy surfaces, the rovibronic energies of CH2+ are calculated by the variational method using the RENNER Hamiltonian. It is found that the accuracy of the perturbation theory method involving many reference configurations is as good as the accuracy of the best ab initio calculations performed by the configuration interaction method with many reference configurations and by the coupled cluster method with a single reference configuration. Empirical refinement of the two parameters of the potential function leads to good agreement between calculation and experiment, except for the wavenumbers of the (A) over tilde (0, 3, 0)(1) <- (X) over tilde (0, 0, 0)(0) transitions.

• 出版日期2008-6