Classical treatment of ion-H2O collisions with a three-center model potential

Abstract

We present calculations of cross sections for one- and two-electron processes in collisions of ${\mathrm{H}}^{+}$, He${}^{2+}$, and ${\mathrm{C}}^{6+}$ with water molecules in the framework of the Franck-Condon approximation. We employ an independent-electron method and a classical trajectory Monte Carlo approach. Anisotropy effects related to the structure of the target are explicitly incorporated by using a three-center model potential to describe the electron-H${}_{2}$O${}^{+}$ interaction. We derive scaling laws with respect to the projectile charge. We also estimate cross sections for molecular fragmentation subsequent to electron removal.