Hi Paul, I believe this is a benign error message from Feff6. At least, the results still seem ok to me in the cases where I've seen the 'Hard test in fovrg' messages: The EXAFS and the muffin tin radii look reasonable to me. Getting the benign messages is probably due to my conversion of the Feff6l to mostly double precision, while older Feff6 (and Feff7) had mixed single and double precision. I see that some of the constants in fovrg.f are still single precision. Feff8 uses a completely different algorithm for this (do I actually understand either of them? No I do not!), so it's not surprising that warnings in one would not occur in the other. Can you send an input file that gives this? I have one that also gives fovrg hard tests messages, but I'd like to see if I can figure this out. Thanks, --Matt