Potential curves splitting in the two-Coulomb-centre problem with different charges

Abstract

The consistent scheme for obtaining quasiclassical (WKB) expansions for solutions of the quasiangular equation in the quantum mechanical two-Coulomb-centre problem is developed. In the framework of this scheme, the quasiclassical angular Coulomb spheroidal wave functions for large distances between the fixed positive charges (nuclei) are constructed for the under-barrier motion of the negative particle (electron). The quasiclassical expression for the exchange interaction \delta E of potential curves at the points of their quasicrossing is found.