Hi, I apologize for being so peevish yesterday. Matt is correct that Dan asked a legitimate question and I offered a very snarky response. Someone just starting out with XAFS doesn't deserve that kind of attitude and should not be discouraged from posting to the mailing list. Dan, I apologize for the 'tude. Please don't let one day in which I was in a bad mood keep you from participating in the community on the mailing list. That said, this line: I entered all the information into Atoms correctly and Atoms ran fine, but when I run Feff I get this message. was the part that triggered my peevish response. Instead of being peevish, though, I should have explained how to better ask the question. Now, I still don't know what the problem was, so I'll use as an example another problem that exists in the current version of Artemis and about which there has been some discussion recently here on the list. There are situations where the potentials list contains atoms that are not in the atoms list and so Feff does not run to completion. One such material that readily triggers this problem is YBa2Cu3O7, the superconductor. Suppose a posting to the mailing list said "I entered the data for YBa2Cu3O7 correctly and atoms ran but then Feff did not run." It is very hard for me to know how to address that because I have run Atoms and Feff within Artemis hundreds of times without any problem. Without more information, I cannot offer good advice. Now consider a posting that says this: I entered the following data for YBa2Cu3O7 into the atoms page in Artemis 0.7.008 on my linux machine: title = YBCO: Y Ba2 Cu3 O7 space = P M M M a = 3.8230 b = 3.8860 c = 11.6810 core = cu1 rmax = 5.20 atoms ! elem x y z tag Y 0.50000 0.50000 0.50000 Ba 0.50000 0.50000 0.18400 Cu 0.00000 0.00000 0.00000 cu1 Cu 0.00000 0.00000 0.35600 cu2 O 0.00000 0.50000 0.00000 o1 O 0.00000 0.00000 0.15800 o2 O 0.00000 0.50000 0.37900 o3 O 0.50000 0.00000 0.37700 o4 Atoms ran to completion, and the feff.inp file looked ok, but when I ran Feff, I saw this written in the window where feff's runtime messages are written: Feff 6L.02 No atoms or overlap cards for unique pot 1 Cannot calculate potentials, etc. Fatal Error: at RDINP What is the meaning of this error and how can I fix it? Do you see how that is a much better explanation of the problem? Rather than asserting that the atoms data was correct, the atoms data used was cut and pasted into the email. That way, I can enter the exact same data into my running copy of Artemis and observe the problem myself. Then, the messages from Feff were transcribed into the email. While I admit that what Feff says is cryptic, I actually understand that message and would have recognized the problem for what it was. Also note that the improved explanation started by stating the version number of Artemis and the computer platform used. (The answer to the example problem: there is a bug in Atoms. The work-around is to increase Rmax in Atoms, then rerun Atoms and Feff.) There are some other places to look for useful clues as to the problem. You will notice that the window that displays the feff runtime messages also contains several other spaces arranged as note tabs. The one marked "Echo" shows every message that has been written to the echo area at the bottom of the main window. Sometimes a useful message gets written to the echo area but then something else comes along. Looking at the history of echo messages sometimes helps. The other space that is very useful is the one labeled "Ifeffit". That space records the most recent 2000 lines of communication between Artemis and Ifeffit. If Ifeffit has ever become confused by something Artemis asks it to do, it's response will be printed in blue text. By examining this text, you can actually uncover lots of clues about the inner workings of Artemis. Another useful bit of information, and one that speaks directly to Dan's original question, can be found in the "Theory" menu. Selecting "Identify this feff calculation" will write something like This Feff: data0.feff0 This project: /home/bruce/.horae/stash/artemis.project.2/ in the echo area. This identifies the space on your hard drive where artemis stores all the data and information from feff that it is using in the current project. It also identifies the current feff calculation with an identifier that is used both internally in the program and as the name of the folder in the project space containing the results of the atoms and feff runs. Thus the feff.inp file generated by atoms in this example would be found at: /home/bruce/.horae/stash/artemis.project.2/data0.feff0/feff.inp I could write up a thorough explanation of the project file format and the contents of its files if anyone is interested. HTH, B -- Bruce Ravel ----------------------------------- ravel@phys.washington.edu Code 6134, Building 3, Room 405 Naval Research Laboratory phone: (1) 202 767 2268 Washington DC 20375, USA fax: (1) 202 767 4642 NRL Synchrotron Radiation Consortium (NRL-SRC) Beamlines X11a, X11b, X23b National Synchrotron Light Source Brookhaven National Laboratory, Upton, NY 11973 My homepage: http://feff.phys.washington.edu/~ravel EXAFS software: http://feff.phys.washington.edu/~ravel/software/exafs/