Juro, this sounds like a problem with the FEFF input. You get this message if you specify absorbers in the POTENTIALS section but not list them in the ATOMS section. Example (for gold oxide): If you do POTENTIALS * ipot z [ label l_scmt l_fms stoichiometry ] 0 79 Au -1 -1 0.01 1 8 O -1 -1 3 2 79 Au -1 -1 2 ATOMS 0.00000 0.00000 0.00000 0 Au1 0.00000 0.58748 -1.39811 1.19247 1 O2 1.92920 1.64570 1.05726 0.47284 1 O1 2.01239 -1.56105 -1.22348 -0.48666 1 O1 2.04220 -0.47075 1.40652 -1.44616 1 O1 2.07154 it will complain that there is no atom for unique potential 2. If you add 1.17495 -2.79622 0.00000 2 Au1 3.03304 it will do the job. If you post the atoms and feff input files I can have a closer look. Norbert -- Dr. rer. nat. Norbert Weiher (norbert.weiher@manchester.ac.uk) School of Chemical Engineering and Analytical Science Sackville Street, Manchester, M60 1QD - Phone: +44 161 306 4468