Quasicrossing of rydberg terms in the problem of two Coulomb centers with strongly differing charges

The comparison equation method is used to obtain asymptotic (with respect to the large internuclear distance $R$) expansions of the energy terms and wave functions of highly excited states in the problem of two Coulomb centers with strongly differing charges. The conditions of applicability of the obtained expressions are found, and a comparison with numerical calculations is made. The results can be used to study charge exchange of the hydrogen atom on a multiply charged ion.