title: Theoretical Debye-Waller factors of alpha-MoO(3) estimated by an equation-of-motion method.
abstract: EXAFS oscillations of MoO(3), which has a highly asymmetric local structure, have been calculated using backscattering amplitudes and phase shifts derived from the FEFF8 code and using Debye-Waller factors from an equation-of-motion method. They were compared with polarization-dependent empirical EXAFS data of the alpha-MoO(3) single crystal at various temperatures. The theoretical EXAFS oscillations of Mo-O bonds for the [001] direction of the single crystal, where two symmetric Mo-O bonds exist, reproduced well the experimental data. On the other hand, the calculated data for the [100] direction, which contain two asymmetric Mo-O bonds with different bond lengths, agree well with the experimental data only after adjustment of the amplitude reduction factors for different Mo-O bonds. EXAFS oscillations of MoO(3) powder were also calculated by the same method, and theoretical parameters that could reproduce the experimental data were found. These results suggest that the equation-of-motion method can evaluate the Debye-Waller factors efficiently in molecules with asymmetric local structures and can reduce curve-fitting parameters.
authors.affiliation: Catalysis Research Center, Hokkaido University, Kita-ku, Sapporo 060-0811, Japan.
authors.forename: W J
authors.initials: WJ
authors.lastname: Chun
authors.forename: K
authors.initials: K
authors.lastname: Ijima
authors.forename: Y
authors.initials: Y
authors.lastname: Ohminami
authors.forename: S
authors.initials: S
authors.lastname: Suzuki
authors.forename: K
authors.initials: K
authors.lastname: Asakura