Many-body calculation of the valence photoemission spectrum of ferrocene

Ionized and excited states of ferrocene: Symmetry adapted cluster–configuration–interaction study

“…Table II lists the ionization energies and the intensities ͑in parentheses͒ calculated by the SAC-CI method and the HF method ͑Koopmans͒. The ionization energies calculated by the ab initio ADC͑3͒ Green's function method 19 and those observed 8,9 are also shown for comparison. The first peak observed at 6.86 eV was calculated at 6.26 eV (1 2 E 2 Ј) as the ionization mainly from 4e 2 Ј MO.…”

“…13 For ferrocene ionization energies, ⌬SCF calculations, 14,15 X␣ scattered-wave calculations, 16,17 and intermediate neglect of differential overlap ͑INDO͒ Green's function calculation 18 have been done. Ohno et al 19 calculated the ionization energies with the ab initio third-order algebraic diagrammatic construction ͓ADC͑3͔͒ Green's function method and proposed the lowest four peaks to be E 2 Ј ͑metal͒, E 1 Ј ͑ligand͒, E 1 Љ ͑ligand͒, and A 1 Ј ͑metal͒. All calculations have contradicted with the experimental assignment, the lowest E 2 Ј ͑metal͒ and A 1 Ј ͑metal͒ states, either qualitatively or quantitatively.…”

Two-Dimensional Penning Ionization Electron Spectroscopy of Open-Shell Metallocenes: Outer Valence Ionic States of Vanadocene and Nickelocene

“…The electronic structure of metallocenes ((η 5 -C 5 H 5 ) 2 M; M is a central metallic atom) has been investigated by photoelectron spectroscopy. − Some of the metallocenes are open-shell compounds, and ionized electronic states of open-shell organometallic compounds are difficult to determine due to mixing of spin states and large electron correlation effects. In the case of closed-shell organometallic compounds, theoretical calculations of ab initio molecular orbital (MO) method for ionic states by post Hartree–Fock theory such as Green’s functional method including electron correlation effects (ADC(3)) or configuration interaction method by the SAC/SAC-CI theory have been successfully utilized to make assignments of the observed electron spectra. For example, we have published a collaboration study between two-dimensional collision-energy/electron-energy-resolved Penning ionization electron spectroscopy (2D-PIES) and the SAC-CI theory for closed-shell organometallic compounds, iron pentacarbonyl (Fe(CO) 5 ) and η 5 -cyclopentadienyl cobalt dicarbonyl ((η 5 -C 5 H 5 )Co(CO) 2 ).…”

Theoretical Study of Photoionization Processes in Fe(C5H5)2

“…Photoelectron spectroscopy (PES) is a very powerful tool for investigating electronic states and checking various features of the bonding interaction between metal and ligands. Consequently, a great deal of experimental and theoretical work has been devoted to the photoelectron spectrum of ferrocene, both as concerns the analysis of the ionization energy data − and the photoelectron dynamics. − The PE spectrum has been long debated and a large number of MO calculations with different degrees of sophistication have been performed − to explain the spectral features observed in the high-resolution He(I) and He(II) experimental spectra 3 . The results often appear controversial, and the assignment of the spectrum remains not completely definite for the first low ionizations.…”