NONADIABATIC FORMULATION OF THE SLOW-ATOMIC-COLLISION PROBLEM IN THE FINITE ELECTRONIC BASIS

The resonating-group method developed for nuclear collisions is used t o obtain equations describing the collisions of slow atoms. On one han d, these equations correctly take into account the indistinguish-abili ty of electrons and scattering boundary conditions and therefore are f ree from the drawbacks of conventional equations in the adiabatic elec tronic basis. On the other hand, they retain the form of the latter eq uations and therefore are in agreement with the generally accepted pic ture of heavy-particle motion in the fields of adiabatic electronic po tentials accompanied by nonadiabatic transitions. The general theory i s illustrated by considering the interaction of two ground-state hydro gen atoms in the Heitler-London electronic basis.