title: Correlation expansion: a powerful alternative multiple scattering calculation method.
abstract: We introduce a powerful alternative expansion method to perform multiple scattering calculations. In contrast to standard MS series expansion, where the scattering contributions are grouped in terms of scattering order and may diverge in the low energy region, this expansion, called correlation expansion, partitions the scattering process into contributions from different small atom groups and converges at all energies. It converges faster than MS series expansion when the latter is convergent. Furthermore, it takes less memory than the full MS method so it can be used in the near edge region without any divergence problem, even for large clusters. The correlation expansion framework we derive here is very general and can serve to calculate all the elements of the scattering path operator matrix. Photoelectron diffraction calculations in a cluster containing 23 atoms are presented to test the method and compare it to full MS and standard MS series expansion.
authors.affiliation: Beijing Synchrotron Radiation Facility, Institute of High Energy Physics, Chinese Academy of Sciences, PO Box 918, Beijing 100049, People's Republic of China. Equipe de Physique des Surfaces et Interfaces, Institut de Physique de Rennes, UMR UR1-CNRS 6251, Campus de Beaulieu, Université de Rennes 1, 35042 Rennes-cedex, France.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Zhao
authors.forename: Didier
authors.initials: D
authors.lastname: Sébilleau
authors.forename: Ziyu
authors.initials: Z
authors.lastname: Wu