The electronic structure and spectrum of Cr3+ in LiCaAlF6 are investigated by using the discrete variational-local density functional (DV-LDF) method with embedded cluster model. The clusters (CrF6)3- with C3, D3d and O(h) point group symmetries embedded in the crystal are treated. The one-electron energy levels, densities of states, orbital populations, spin polarization splittings and energies of some terms are calculated. The results show that the relaxation of F- ions around the Cr3+ impurity is inevitable, and that the D3d and O(h) (CrF6)3- clusters, with an extended bond-length R(Cr-F) chosen to be equal to 1.88 angstrom can represent this relaxation in a much better way. All the ligand-field transition energies, which are obtained from the transition-state energy and the Griffith parameters, as yielded by a restricted one-electron DV-LDF calculation, compare well with the experimental ones.
Electronic-structure and Spectrum of Cr3+ In Licaalf6
TOIGO, FLAVIO
1991
Abstract
The electronic structure and spectrum of Cr3+ in LiCaAlF6 are investigated by using the discrete variational-local density functional (DV-LDF) method with embedded cluster model. The clusters (CrF6)3- with C3, D3d and O(h) point group symmetries embedded in the crystal are treated. The one-electron energy levels, densities of states, orbital populations, spin polarization splittings and energies of some terms are calculated. The results show that the relaxation of F- ions around the Cr3+ impurity is inevitable, and that the D3d and O(h) (CrF6)3- clusters, with an extended bond-length R(Cr-F) chosen to be equal to 1.88 angstrom can represent this relaxation in a much better way. All the ligand-field transition energies, which are obtained from the transition-state energy and the Griffith parameters, as yielded by a restricted one-electron DV-LDF calculation, compare well with the experimental ones.
Pubblicazioni consigliate
I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
