THE AB-INITIO CALCULATION OF VERY MANY TRIPLY IONIZED STATES OF MOLECULAR-SYSTEMS

We report on the implementation and first application of the second or der algebraic diagrammatic construction approximation of the three-par ticle Green's function. This method allows the ab initio calculation o f a large number of triply ionized states. As a first example the trip le ionization spectrum of the water molecule is investigated. The resu lts obtained with this method are discussed and shown to be of compara ble accuracy to those of configuration interaction calculations of muc h larger and faster scaling computational size.