Full-potential multiple scattering for core electron spectroscopies

Abstract

We present a rigorous derivation of a real space full-potential multiple-scattering theory(FP-MST), valid both for continuum and bound states, that is free from the drawbacksthat up to now have impaired its development, in particular the need to use cell shapefunctions and rectangular matrices. In this connection we give a new scheme togenerate local basis functions for the truncated potential cells that is simple,fast, efficient, valid for any shape of the cell and reduces to the minimum thenumber of spherical harmonics in the expansion of the scattering wavefunction. Thisapproach provides a straightforward extension of MST in the muffin-tin (MT)approximation, with only one truncation parameter given by the classical relationlmax = kRb, wherek is the photo-electronwavevector and Rb the radius of the bounding sphere of the scattering cell. Some numerical applications of thetheory are presented, both for continuum and bound states.