Abstract
A three‐dimensional potential energy surface for the ^2^A′ ground state of the system (NeH~2~)^+^ (^2^Σ^+^ in collinear geometry) has been calculated at SCF and CEPA levels. This surface describes the abstraction reaction
which is endoergic by 0.57 eV (Δ__H__^0^~0~) and has been studied recently by different experimental groups at low collision energies. Our CEPA calculations yield an endoergicity of 0.55 eV (Δ__H__^0^~0~). The ^2^A′ surface has a minimum at collinear geometry with R~Ne—H~ = 2.29 a~0~ and R~HH~ = 2.08 a~0~ and a well depth of 0.49 eV relative to Ne + H^+^~2~. The effects of electron correlation on the shape of the surface and on the well depth are discussed.
An analytic fit of the collinear part of the surface has been constructed based on Simon's proposal of using polynomials in the coordinates (R____R~e~)/R instead of (R____R~e~). The fitted potential is used for quantum mechanical scattering calculations with the finite element method (FEM). Preliminary results for reaction probabilities for H^+^~2~ in different vibrationally excited states are given and compared to the experimental results.