Electron impact dissociation of molecules and molecular ions

In most collisions between electrons and molecules or molecular ions, there is little transfer of energy from the electron to the nuclear motion of th e system. However, in resonant cases, the electron forms a temporary state, which changes the forces between the atoms, leading to vibrational excitat ion and in some cases dissociation. We have developed a completely ab initi o approach to these problems. We use the Complex Kohn variational principle to determine the resonance parameters and a wave packet method to describe the nuclear dynamics. We will outline the basics of the method and show ex amples in dissociative recombination and dissociative attachment.