PROGRESS IN SCF-SW-XALPHA AB INITIO XANES CALCULATIONS FOR CHROMIUM HEXACARBONYL BASED ON GENERAL NON-MUFFIN-TIN POTENTIALS

We describe progress towards the performance of SCF-SW-Xalpha calculations of photo-absorption cross-sections based on the theory of Natoli et al. for non-muffin-tin potentials. A crucial requirement is the accurate modelling of the electron-molecule potential using spherical harmonic expansions. We describe how this has been achieved and what difficulties are encountered. In the particular case of our model compound, chromium hexacarbonyl, we show what muffin-tin calculations produce and show that we may expect significant improvements from a non-muffin-tin calculation. Finally, we comment on the programming problems involved in these computations