AUGER SPECTRUM OF OCTATETRAENE BY A 2-PARTICLE PROPAGATOR METHOD

A matrix eigenvalue formulation is presented for the pole search probl em occurring in the renormalized two-particle Green's function method. Emphasis is on the method's suitability for calculations on large mol ecules. Thus it employs a first-order irreducible vertex part. The ref ormulation is achieved by a transformation from the doubly-occupied or bital space to a space spanned by orbital and satellite indices. The m ethod is applied to the calculation of the Auger spectrum of octatetra ene. Evaluation of the average hole-hole separation for every state sh ows that the Auger spectrum of octatetraene should in general already provide a model for the Auger spectrum of polyacetylene. However, the results also predict that several single-state peaks at low binding en ergy can be expected in the Auger spectrum of octatetraene. These shou ld be due to delocalized states which are characteristic for long fini te polyenes. (C) 1996 American Institute of Physics.