Determination of the radial coupling between molecular states

The radial coupling between the first 1Σ+ states of HeNe2+ has been calculated in the adiabatic representation by means of the finite differences technique and in a non-adiabatic representation using a projection method previously developped. The behaviour of the radial coupling matrix elements is discussed in view of using them in the collision equations. In the quasi-diabatic basis, radial couplings are shown to be negligibly small and the non-adiabatic transformation provides a rapid and accurate determination of these couplings between adiabatic wavefunctions.