Coupled-channel calculations of the electronic energy loss

A review is given on the use of the coupled-channel method to calculate the electronic energy loss of ions penetrating matter. This first principle calculation, based on an expansion of the time-dependent electronic wave function in terms of atomic orbitals, has been applied to evaluate the impact parameter and angular dependence of the electronic energy loss and the stopping cross-section of ions (antiprotons, H and He) colliding with H and He atoms at energies of 1-500 keV/amu. The results are compared to experimental data as well as to others current energy-loss models.