Abstract
General equations for the calculation of correlated single-channel photoionization cross-sections of randomly oriented molecules are presented. These equations, employing a plane wave orthogonalized to all (occupied and virtual) bound molecular orbitals as a wavefunction for the photoelectron, are derived in a many-body Green's function framework. Several decoupling approximations for the expansion of the one-particle propagator are then used to compute angle-averaged photoionization cross-sections for a Mg Kα photon source and for a representative set of molecules: CH4, H2O, C2H2, N2, and CO. Both orthogonality corrections to the continuum orbital and many-body corrections in the description of the ionization process are shown to be important for accurate simulations of soft X-ray ionization spectra.
Original language | English |
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Pages (from-to) | 655-686 |
Number of pages | 32 |
Journal | Molecular physics |
Volume | 83 |
Issue number | 4 |
DOIs | |
Publication status | Published - 1994 |