Valence ionization spectra of group six metal hexacarbonyls studied by the symmetry-adapted cluster-configuration interaction method

Abstract

The valence ionization spectra up to 20 eV of group six metal carbonyls, chromium hexacarbonyl, molybdenum hexacarbonyl, and tungsten hexacarbonyl were studied by the symmetry-adapted cluster-configuration interaction (SAC-CI) method. The assignments of the spectra are given based on reliable SAC-CI calculations. The relativistic effects including the spin-orbit effects are important for the ionization spectrum of W(CO)(6). The relation between the metal-CO distance and ionization energies was examined. The lowest ionization energies of the three metal carbonyls are approximately the same because of the energy dependence of the metal-CO length and relativistic effects. In Cr(CO)(6), the Cr-CO interaction significantly increases the lowest ionization energy in comparison with Mo(CO)(6) and W(CO)(6) because of the relatively short metal-CO bond length. The relativistic effect reduces the lowest ionization energy of W(CO)(6) because the effective core potential of 5d electrons is more efficiently screened as a result of the relativistic contraction of the inner electrons.

Theoretical study of valance photoelectron spectra of hypoxanthine, xanthine, and caffeine using direct symmetry‐adapted cluster/configuration interaction methodology

“…As we know, this SAC-CI SD-R approach produces quite accurate results for one-electron processes 30,32,33 in this work.…”

“…The other two p-type molecular orbitals are occupied by the lone pairs of the NH groups in the molecule. Based on the above explanations, the molecular orbitals (35,34,32,29,28,24) and (35,34,33,29,28,24) in Table 1 and Supporting Information Table S4 can be considered as the occupied p molecular orbitals. The four unoccupied p-type …”

Spin-orbit sensitive hard x-ray probe of the occupied and unoccupied5ddensity of states

“…The importance of the 5d SOI for the ionization spectrum of W(CO) 6 was proposed in Ref. 35. X-ray magnetic circular dichroism (XMCD) measurements confirmed the presence of a large SOI.…”

Outer- and inner-valence satellites of carbon dioxide: Electron momentum spectroscopy compared with symmetry-adapted-cluster configuration interaction general-R calculations

“…7,8,14,15 On the theoretical side, highly accurate SAC-CI (symmetryadapted-cluster configuration interaction) general-R method has achieved "fine theoretical spectroscopy" for the ionization of a series of molecules. [20][21][22][23][24][25][26] Carbon dioxide, which has considerable fundamental as well as applied interests, has been extensively studied by means of various experimental techniques and theoretical calculations. Experimentally, carbon dioxide has been studied by PES using Mg Kα radiation, 27 He I PES, 28 He II PES, 29,30 synchrotron radiation photoelectron spectroscopy (SRPES), 2, 3 and also by both binary [31][32][33][34] and dipole 11,35 (e, 2e) spectroscopy.…”