Some representative results from applications of the second order, diagonal 2ph-TDA and quasi-particle decouplings of the biorthogonal dilated electron propagator based on a complex scaled bivariational SCF to the investigation of 2P Mg, 2B2gC2H4 shape and 2S (1s-1) Be+ Auger resonances are presented. These results demonstrate the effectiveness of the dilated electron propagator in calculation of energies and widths as also in unravelling of the mechanistic details of resonance formation and decay. The Feynman–Dyson amplitudes are shown to effectively isolate the LUMO as the resonant orbital. © 1998 Taylor & Francis Group, LLC.