A systematic analysis of the spectra of trivalent actinide chlorides in D sub 3h site symmetry

Technical Report · Wed Nov 01 04:00:00 EST 1989

DOI:https://doi.org/10.2172/7017566· OSTI ID:7017566

Carnall, W T

The optical spectra of actinide ions in the compound AnCl{sub 3} and doped into single crystal LaCl{sub 3} were interpreted in terms of transitions within 5f{sup N} configurations. Energy-level calculations were carried out using an effective operator Hamiltonian, the parameters of which were determined by fitting experimental data. Atomic and crystal-field matrices were diagonalized simultaneously assuming an approximate D{sub 3h} site symmetry. The spectroscopic data were taken from the literature but in most cases supplemented by unpublished measurements in absorption and in fluorescence. Spectroscopic data for each ion were analyzed independently, then the model parameters were intercompared and in many cases adjusted such that in the final fitting process the principal interactions showed uniform trends in parameter values with increasing atomic number. Consistent with analyses of the spectra of lanthanide ions in both LaCl{sub 3} and LaF{sub 3}, abrupt changes in magnitude of certain crystal-field parameters were found near the center of the 5f{sup N}-series. This resulted in two groups of parameter values, but with consistent trends for both halves of the series, and generally very good agreement between observed and computed energies. A new energy level chart based on computed crystal-field level energies for each trivalent actinide ion has been prepared. in addition, the parameters of the atomic part of each 5f{sup N} Hamiltonian were used to calculate the matrix elements of U{sup ({lambda})} for selected transitions. The values were tabulated to facilitate calculation of intensity-related parameters for 5f{sup N}-transitions using the Judd-Ofelt theory. 44 refs., 10 figs., 3 tabs.

• Research Organization: Argonne National Lab., IL (USA)
• Sponsoring Organization: DOE/ER
• DOE Contract Number: W-31109-ENG-38
• OSTI ID: 7017566
• Report Number(s): ANL-89/39; ON: DE90008104
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400102 -- Chemical & Spectral Procedures
640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ACTINIDE COMPOUNDS
ACTINIDES
ACTINIUM CHLORIDES
ACTINIUM COMPOUNDS
CALCULATION METHODS
CHLORIDES
CHLORINE COMPOUNDS
CRYSTAL STRUCTURE
ELEMENTS
ENERGY LEVELS
ENERGY SPECTRA
HALIDES
HALOGEN COMPOUNDS
HAMILTONIANS
MATHEMATICAL OPERATORS
MATRIX ELEMENTS
METALS
QUANTUM OPERATORS
SPECTRA