The relativistic four-component static-exchange approximation for core excitation processes in molecules (Articolo in rivista)

Type
Label
  • The relativistic four-component static-exchange approximation for core excitation processes in molecules (Articolo in rivista) (literal)
Anno
  • 2006-01-01T00:00:00+01:00 (literal)
Alternative label
  • Ekstrom U., Norman P., Carravetta V. (2006)
    The relativistic four-component static-exchange approximation for core excitation processes in molecules
    in Physical review. A
    (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#autori
  • Ekstrom U., Norman P., Carravetta V. (literal)
Pagina inizio
  • 22501 (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#numeroVolume
  • 73 (literal)
Rivista
Note
  • ISI Web of Science (WOS) (literal)
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#affiliazioni
  • Department of Physics, Chemistry and Biology, Linkoeping University, SE-581 83 Linkoeping, Sweden Istituto per i Processi Chimico-Fisici, Area della Ricerca del C.N.R., via G. Moruzzi 1, 56124 Pisa, Italy (literal)
Titolo
  • The relativistic four-component static-exchange approximation for core excitation processes in molecules (literal)
Abstract
  • A generalization of the static-exchange approximation for core-electron spectroscopies to the relativistic four-component realm is presented. The initial state is a Kramers restricted Hartree--Fock state and the final state is formed as the configuration interaction single excited state, based on the average-of-configurations for (n-1) electrons in n near-degenerate core-orbitals for the reference ionic state. It is demonstrated that the static-exchange Hamiltonian can be made real by considering a set of time-reversal symmetric electron excitation operators. The static-exchange Hamiltonian is constructed at a cost that parallels a single Fock matrix construction in a quaternion framework that fully exploits time-reversal and spatial symmetries for the D_{2h} point group and subgroups. The $K$- and $L$-edge absorption spectra of H2S are used to illustrate the novelties of the methodology. The calculations adopts the Dirac--Coulomb Hamiltonian, but the theory is open-ended towards improvements in the electron-electron interaction operator. It is demonstrated that relativistic effects are substantial for the $L$-edge spectrum of sulphur, and substantial deviations from the statistical 2:1 spin-orbit splitting of the intensity distribution are found. The average ratio in the mixed region is 1.54 at the present level of theory. (literal)
Prodotto di
Autore CNR
Insieme di parole chiave

Incoming links:


Prodotto
Autore CNR di
Http://www.cnr.it/ontology/cnr/pubblicazioni.owl#rivistaDi
Insieme di parole chiave di
data.CNR.it