C. R. Natoli

The quantitative Jahn-teller distortion of the Cu2+ site in aqueous solution by xanes spectroscopy

Abstract The Jahn-Teller distortion of the Cu2+ (H2O)6 cluster in aqueous solution has been studied by X-ray near edge structure spectroscopy. Theoretical calculations in the multiple scattering formalism have allowed us to identify in the XANES (X-ray absorption near edge structure) spectrum the characteristic feature of this distortion and to estimate from the energy separation between this feature and the main shape resonance a tetragonal distortion of about 0.58 ± 0.06 A. We give “a priori” arguments whereby a conventional EXAFS (extended X-ray absorption fine structure) analysis, even supplied with state of art theoretical improvements, fails to discriminate between distorted or undistorted clusters in solution.

Bond Length Determination Using XANES

The use of XANES (X-ray Absorption Near Edge Structures) as a tool for determining coordination geometry, symmetry of the unoccupied valence electronic states or effective charge on the absorbing atom has been suggested by several authors [1], [2], [3].

Three particle correlation function of metal ions in tetrahedral coordination determined by XANES

Abstract The three particle correlation function of local atomic distribution at metal ion sites in solutions has been extracted from XANES (X-ray absorption near edge structure) spectra of [CrO 4 ] 2− and [MnO 4 ] − ions measured by using synchrotron radiation. The absorption cross section for 1 s core level excitation is calculated in the real space multiple scattering approach using the Hedin and Lundqvist energy dependent potential. We show that in these systems the expansion of the total absorption cross section in terms of contributions of higher order scattering processes is possible over a large energy range. This gives a unified theory of XANES and EXAFS and allows the third order correlation function to be extracted from experimental data.

Spin-1 effective Hamiltonian with three degenerate orbitals: An application to the case of V2O3

Motivated by recent neutron and x-ray observations in

Application of a complex potential to the interpretation of Xanes spectra the case of Na K-edge in NaCl

{\mathrm{V}}_{2}{\mathrm{O}}_{3},

Multiple-scattering approach with complex potential in the interpretation of electron and photon spectroscopies

we derive the effective Hamiltonian in the strong coupling limit of an Hubbard model with three degenerate

Origin of the pre-peak features in the oxygen K-edge x-ray absorption spectra of LaFeO3 and LaMnO3 studied by Ga substitution of the transition metal ion

{t}_{2g}

A multiple-scattering theory of circular and linear dichroism for photoemission and photoabsorption

states containing two electrons coupled to spin

Analyses of Sr/La X-ray-absorptio-near-edge structure in T-phase La2−xSrxCuO4 compounds

S=1,

Critical reexamination of the nonreciprocal x-ray gyrotropy in V 2 O 3

and use it to reexamine the low-temperature ground-state properties of this compound. An axial trigonal distortion of the cubic states is also taken into account. Since there are no assumptions about the symmetry properties of the hopping integrals involved, the resulting spin-orbital Hamiltonian can be generally applied to any crystallographic configuration of the transition metal ion giving rise to degenerate