An ab initio study of the ground and excited electronic states of the methyl radical

作者：Zanchet A; Banares L; Senent M L; Garcia Vela A^*

来源：Physical Chemistry Chemical Physics, 2016, 18(48): 33195-33203.

DOI：10.1039/c6cp05960k

The ground and some excited electronic states of the methyl radical have been characterized by means of highly correlated ab intio techniques. The specific excited states investigated are those involved in the dissociation of the radical, namely the 3s and 3p(z) Rydberg states, and the A(1) and B-1 valence states crossing them, respectively. The C-H dissociative coordinate and the HCH bending angle were considered in order to generate the first two-dimensional ab initio representation of the potential surfaces of the above electronic states of CH3, along with the nonadiabatic couplings between them. Spectroscopic constants and frequencies calculated for the ground and bound excited states agree well with most of the available experimental data. Implications of the shape of the excited potential surfaces and couplings for the dissociation pathways of CH3 are discussed in the light of recent experimental results for dissociation from low-lying vibrational states of CH3. Based on the ab initio data some predictions are made regarding methyl photodissociation from higher initial vibrational states.

• 出版日期2016