Ab initio calculation of the $CH(X\ ^{2}\Pi, A\ ^{2}\Delta , B\ ^{2}\Sigma^{+}, C\ ^{2}\Sigma^{+}) + Ne (^{1}S)$ potential energy surfaces

Author Institution: Department of Chemistry, Emory UniversityWe report multireference configuration-interaction calculations for the four lowest adiabatic doublet potential energy surfaces of $CH(X \ {^{2} \Pi}, A \ {^{2}\Delta}, B \ {^{2}\Sigma}^{-},\\ C \ {^{2} \Sigma}^{+}) - Ne \ (^{1} S)$ open shell van der Waals molecule. The CH-Ne van der Waals complex is found lo be bound by about $30.5 cm^{-1}$ in the electronic ground slate with a T-shaped geometry. The A, B, and C state potential energy surfaces have two minima at collinear geometries which correspond to isometric CH-Ne and Ne-CH structures. The dissociation energies for the excited states range from $35 cm^{-1}$ to $45 cm^{-1}$ ,where the global minima in each excited state can be found at the linear CH-Ne configuration. The calculated potential energy surfaces have been fitted lo an analytical function and used lo calculate bound rovibrational levels of the CH-Ne complex. In order to investigate why $CH (C \ {^{2} \Sigma}^{+})$-Ne complex was not seen experimentally, we have calculated transition moments for the transition ground state to all there excited states