Accession Number : AD0664181

Title :   ENERGY LEVELS AND VIBRONIC INTENSITIES IN CRYSTALS HAVING U(4+) HALIDE COMPLEXES.

Descriptive Note : Technical rept.,

Corporate Author : CALIFORNIA UNIV LOS ANGELES DEPT OF PHYSICS

Personal Author(s) : Schreiber,Charles Leonard

Report Date : NOV 1967

Pagination or Media Count : 197

Abstract : A study was made of the vibronic absorption spectra of ((CH3)4N) 2UCl6, Cs2UCl6, and Cs2UBr6 salts. The similarities observed in these spectra both in the intensities and in the transition energies are shown to be based on the existence of a tightly bonded UX6(2-) halide complex which has a large 'crystal field' with octahedral Oh symmetry interacting with the uranium ion. A diagonalization of the Hamiltonian containing the electrostatic, spin-orbit, and crystal field interactions within a basis of states from the 5f(2) configuration of the U(4+) free ion is made and the eigenvalue spectrum for the low-energy electronic states (within 4 ev of the ground state) is fitted to within an average deviation of 130/cm. The vibronic interaction Vev between the electronic and vibrational states of the crystal is approximated by a model involving the 'odd' vibrational modes of the UX6(2-) complex. The intermediate states mixed into the 5f(2) states by this vibronic interaction are used to obtain electric dipole vibronic transitions. Several selection rules which limit the useful intermediate states and the allowed vibronic transitions are discussed. (Author)

Descriptors :   (*COMPLEX COMPOUNDS, URANIUM COMPOUNDS), (*URANIUM COMPOUNDS, ABSORPTION SPECTRA), (*ATOMIC ENERGY LEVELS, URANIUM), INFRARED SPECTROSCOPY, CRYSTAL LATTICES, FIELD THEORY, WAVE FUNCTIONS, ELECTRON TRANSITIONS, INTENSITY, LEAST SQUARES METHOD, AMMONIUM COMPOUNDS, CESIUM COMPOUNDS, CHLORIDES, BROMIDES, THESES

Subject Categories : Atomic and Molecular Physics and Spectroscopy
      Solid State Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE