ABSTRACT
In chapters 11-19, we shall review the progress in solving problems encountered in non-relativistic ion (atom)-atom collisions with the participation of two active electrons. These processes involve e.g. (i) scattering between a bare nucleus (projectile) P of charge ZP and a helium-like atomic system comprized of two electrons e1 and e2 that are initially bound to the target nucleus T of charge ZT i.e. the ZP − (ZT; e1, e2)i collisions, (ii) scattering between two hydrogen-like atoms (ZP, e1)i1 and (ZT, e2)i2 , etc. An adequate theoretical description of these collisional processes requires solutions to difficult four-body problems with four actively participating particles, including two electrons and two nuclei.
