Ab initio calculations of resonant x-ray emission spectra for the N_2O molecule: I. Oxygen K spectra

For pt.I see ibid., vol.28, p.357-72 (1995) X-ray emission transition energies and probabilities have been calculated for the 3 pi and 8 sigma core-excited resonant states of the nitrogen atoms in the N2O molecule at the ab initio Delta SCF level. Initial- and final-state wavefunctions were generated using fully relaxed Hartree-Fock wavefunctions, and the transition probabilities were calculated with multicentre contributions. The amount of 2p electron population in the final-state valence-hole was a determining factor in producing changes in the X-ray spectra for the resonant states relative to the diagram states. Geometry optimizations were performed on the core-ionized and core-excited states to measure the effects of changes in the geometry of the initial states. Occupation of the 3 pi resonant orbital produced small changes in the initial-state geometry while occupation of the 8 sigma resonant orbital produced substantial changes in the initial-state geometry. It was determined that inclusion of multicentre contributions for each case is essential for analysing the calculated spectra. Experimental data are required to test the theoretical predictions.