AB-INITIO PROPAGATOR ANALYSIS OF TRIPLE-CHARGE-TRANSFER SPECTRA FOR CARBON-DISULFIDE

Ab initio propagator calculations for triple ionizations of the carbon disulphide molecule to quadruplet states of CS23+ have been performed for transition energies up to 80 eV, using the second-order algebraic diagrammatic construction (ADC(2)) method. Energies predicted for mai n transitions, arbitrarily defined as those to CS23+ states having at least 20% weight in 3-hole configurations, are found to correlate well with those of a range of peaks exhibited in triple-charge-transfer sp ectra for the collisions of 6 keV Cl2+ ions with gas-phase CS2. The AD C(2) results also enable an appraisal of the predictions of a semi-emp irical method previously used to analyse the spectra. (C) 1997 Elsevie r Science B.V.