A complex absorbing potential electron propagator approach to resonance states of metastable anions

Abstract

Abstract An earlier developed electron propagator method for the treatment of electron attachment to molecules within the non-Dyson algebraic-diagrammatic construction framework (EA-ADC) is extended by inclusion of the complex absorbing potential (CAP). The resulting method allows for the investigation of resonance states of metastable anions. Approximation schemes up to third-order perturbation theory for the electron propagator (EA-ADC(3)) are implemented. The CAP operator is treated up to second-order using the intermediate state representation formalism (ISR(2)) and the subspace projection technique. The CAP/EA-ADC(3) method is tested in first applications to the resonances in CO and N2 molecules associated with electron attachment to their low-lying π*-orbitals. The results of the calculations agree well with the available experimental and theoretical data and demonstrate the CAP-augmented EA-ADC modeling can become a useful tool for theoretical studies of metastable electron-attached states.