Auger spectrum of octatetraene by a two‐particle propagator method

A matrix eigenvalue formulation is presented for the pole search problem occurring in the renormalized two‐particle Green’s function method. Emphasis is on the method’s suitability for calculations on large molecules. Thus it employs a first‐order irreducible vertex part. The reformulation is achieved by a transformation from the doubly‐occupied orbital space to a space spanned by orbital and satellite indices. The method is applied to the calculation of the Auger spectrum of octatetraene. Evaluation of the average hole–hole separation for every state shows 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 energy can be expected in the Auger spectrum of octatetraene. These should be due to delocalized states which are characteristic for long finite polyenes.