Julius, I am CCing my response to the Ifeffit mailing list (http://millenia.cars.aps.anl.gov/mailman/listinfo/ifeffit) which is the appropriate venue for questions about the software. The problem you report is surprising to me and certainly not something I see normally. I will need to see an example on my own computer. If you could post an example of crystal data that triggers this, that would help. When you send this to the mailing list, also let us know what version of the software you are using. B Bruce Ravel ------------------------------------ bravel@bnl.gov National Institute of Standards and Technology Synchrotron Methods Group at NSLS --- Beamlines U7A, X24A, X23A2 Building 535A Upton NY, 11973 Homepage: http://xafs.org/BruceRavel Software: https://github.com/bruceravel ________________________________ From: Julius Campecino [jcampecino@gmail.com] Sent: Saturday, November 09, 2013 11:58 AM To: Ravel, Bruce Subject: error in ATOMS Hi Bruce, I am a new user of ATOMS (as well as Athena and Artemis). Whenever I try to run atoms it gives me this error "Can't call method "tag" on an undefined value at C:/strawberry/perl/site/lib/Demeter/Atoms.pm line 662." I do not know how to fix that or go around it. Hopefully you can help. Thank you, Bruce. Julius