Multiple-scattering method

Fig. 22. Best fit between experimental results and computed EXAFS employing the full multiple scattering method. The model is depicted in the bottom right figure [Reprinted from Thomas and Sankar (104) with permission. Copyright (2001) American Chemical Society].

The Xa multiple scattering method generates approximate singledeterminant wavefunctions, in which the non-local exchange interaction of the Hartree-Fock method has been replaced by a local term, as in the Thomas-Fermi-Dirac model. The orbitals are solutions of the one-electron differential equation (in atomic units)... 

In order to indicate the theoretical ideas involved in LEED crystallography, we now outline the main dynamical (i.e., multiple-scattering) methods used to compute 1-V curves for comparison with the experiment (cf., also References 2a and 2f). 

Smith IM, Thompson DG, Blum K (1998) Chiral effects in electron scattering by molecules using a continuum multiple scattering method. J Phys B 31 4029... 

Dill, D., and J. L. Dehmer (1974). Electron-molecule scattering and molecular photoionization using the multiple scattering method. J. Chem. Phys. 61, 693-99. 

Lie, S. K., M. Braga, and C. A. Taft (1988). Electronic structure, hyperfine interactions, and radial densities in the Fe tetrahedral sulfide as calculated by the multiple-scattering method. Phys. Rev. B38, 4382-87. 

To calculate the cross section for photoionization, multiple scattering theory within the framework of a single-particle is presented. The multiple scattering method has been developed in nuclear physics to calculate nuclear scattering cross sections and in solid state physics to compute the electronic structure of solids. 

The theoretically based method [9] suffers from the use of a large number of adjustable parameters in the data analysis. However, an alternate theoretical model has recently been proposed which addresses some of the deficiencies [104]. Specifically, the multiple-scattering method incorporates interactions that occur between the absorbing metal and groups of backscattering atoms, enabling simulation of unfiltered experimental EXAFS data [103-105]. 

An attempt to describe the concentration dependence of the DOS at the Fermi level in NbC Ni (x = 1.0, 0.75, 0.25, 0.12, and 0) was undertaken by Nikiforov and Kolpachev (1988) and Kolpachev and Nikiforov (1988). They used a multiple scattering method in the local coherent potential approximation. Variations in the solid solution composition caused the greatest changes in the nonmetal p-symmetry states and in the part of the d-band located close to the Fermi level. At the same time, comparison of the DOS of the calculated clusters and photoelectron spectra of Nb ternary alloys obtained by Ichara and Watanabe (1981) shows that the calculations only roughly reproduce the peculiarities of the NbC jNi c valence spectrum the energy separation of the p-d- and d-bands is considerably overestimated and there are some additional peaks in the DOS which are not seen in the experimental spectrum. 

Use of self-consistent multiple-scattering methods that measure the AsO adsorption on TiO ... 

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