Abstract :
An extensive set of data has been determined for a few low lying diabatic states of the (HeH2)+ system with a view to make possible future theoretical investigations of the He+ + H2 → HeH+ + H∗ (n=2) reaction dynamics The data are produced in two steps. Firstly, ab initio calculations are carried out which follow a similar scheme to that proposed by Kubach et al.: SCF, IVO and CIs in blocks. Secondly, due to the modest sizes of the considered CIs, the latter results are corrected in an ad hoc manner that insures the proper placing and exact shapes of the asymptotic potential energy curves and introduces shape corrections of the potential energy surfaces when the triatomic system forms. The adequacy of the proposed correction scheme is attested by various comparisons with earlier work. Selected samples of the results show the behaviour of the potential energy surfaces, the diabatic curve crossing pattern, the crossing seams and the diabatic couplings, in various geometries for both reactant HeHeH arrangements.
