On the useful range of application of molecular dynamics simulations in the recoil interaction approximation
The validity of the binary collision (BC) approximation and of the so-called recoil interaction approximation (RIA) in ion-solid interactions at low energies is investigated by comparison with molecular dynamics (MD) simulations. The systems studied are channeling through a (1 1 0) oriented layer of Si, implantation into a (1 0 0)-Si target, and reflection from (1 0 0)-Si. It is found that the BC approximation does not introduce significant errors in the case of channeling simulations even at very low energies. Under non-channeling conditions an upper limit to the break-down energy of the BC approximation in Si is given by 30 M10.55 eV, taking 5% deviation in the projected range as the criterion.