Hi Matt, Alright, Here additional files to the one (Athena_chi.dat) I send in a previous email. 1) one feff.inp file and the related chi.dat file. 2) the original and manually cut chi(k) spectrum of Fe.060 (generated from Ifeffit\examples\Athena\Fe\Fe.060). As this tiny bug is occurring for all types of data (measured & simulated), I do not believe that there is any relation to FEFF. It only seems that the newest version of Athena is not able to "interpolate" the "missing" chi(k) data, while Artemis does. Thanks for your help. Oli ++++++++++++++++++++++++++++++++++++:-) Olivier Jacquat Soil Chemistry group Institut of Biogeochemistry and Pollutant Dynamics ETH Zürich Universitätstrasse 16, CHN F71 8092 Zürich-Switzerland Tel: +41 44 633 60 28 Fax: +41 44 633 11 18 Email: olivier.jacquat@env.ethz.ch