Many-body calculation of electron affinities: C2and a prediction for P2

Abstract
The electron affinities of the molecules, C2and P2are calculated by the Green's function formalism which has been successful in determining accurate ionisation potentials of atoms and molecules. The adiabatic electron affinities obtained are AEA(C2)=3.60 eV and AEA(P2)=0.30 eV compared to the experimental values of 3.54 eV and 0.24+or-0.23 eV respectively. The vibrational structure in the radiative electron-attachment spectra of C2and P2is also computed. There is a close relationship between the vibrational structures in electron-attachment and photodetachment spectra.