In the case of slow ion collisions, the projectile velocity is much smaller than the velocity of bound electrons in the atom or molecule (v_collision ≤ v_electron) and usually the collision energy varies between 1 keV and 100 keV, respectively. Due to this small collision velocity the target electrons are able to adjust their electronically states to the adiabatically changing core potentials; the electrons are “molecularized” between the projectile and the target. Here the most probable reaction channel is the charge transfer from one collision partner to the other.

Saddle Point Ionization
Over Barrier Model
Single Electron Vortices