Characterization of the temporary anion states of metal carbonyl complexes: an MS-X.alpha. and ETS study of chromium hexacarbonyl and iron pentacarbonyl

Threshold Photoionization Study of Fe(CO)5 versus ab Initio Calculations

“…We note that our decomposition overcomes the artifacts of Mulliken's population analysis (MPA), which arise when diffuse basis functions are used. In the present system diffuse functions needed to describe 4s and 4p orbitals make the MPA quite unreliable, as pointed out by XR STSM 35 8.2 9.6 XR STSM 12 7.7 9.0 XR STSM 12 9.0 10.2 XR 63 8.87 9.83 INDO-Koopmans 64 9.01 10.33 SCF-Koopmans 54 7.75 Green's function method 33 8.6 9.9 Bauschlicher. 56 Notice that Tables 3 and 4 supply complementary information: the former concerns the actual localization of the QBOs, while the latter contains the composition of the CMOs in terms of the (quasi-localized) QBOs.…”

“…Unfortunately, except when the hole is in the HOMO of each symmetry, it may be difficult to achieve the convergence of the SCF procedure. In the Xα calculations , performed on Fe(CO) 5 , the repolarization effect has been partially taken into account by means of the Slater transition state method , (STSM). The STSM consists essentially of using an occupation number of one-half for the spin−orbital from which the electron is taken away.…”