A classical and semiclassical study of collisions between X ions and water molecules.

Collisions of He, Li and C ions with water molecules are studied at energies ranging between 20 keV u and 500 keV u. Three methods are employed: the classical trajectory Monte Carlo (CTMC), the expansion of the scattering wave function in terms of asymptotic frozen molecular orbitals (AFMO) and a lattice method to numerically solve the time-dependent Schrödinger equation (GridTDSE). Total cross sections for single ionization, single electron capture, transfer ionization and electron production are calculated and compared with previous close-coupling calculations and experiments. The fragmentation branching ratios are discussed.