On Thursday 16 July 2009 04:42:41 pm you wrote:
When I try to obtain the path with the attached cif file, I find distance As_O(8) = 2.142 A, this is uncorrect, because there is no oxygen atom at that distance. What is going on?
Hi Elsa, For some reason, Artemis does the wrong thing with the setting of the space group. According to your CIF file, the proper setting of the space group is P 21/n. For some reason, when Artemis reads that CIF file, it uses P 21/c as the space group symbol. That is strange behavior -- I will have to investigate what is going on. The work-around on the Atoms page in Artemis is to change the space group to "P 21/n" before running feff. If you are using Atoms at the command line, you will have to tell Atoms to write out an atoms.inp file, edit that, then run feff. That's all a bit irritating, but it is at least workable. When I ran your cif file after specifying "P 21/n" on the Atoms page, I got this for the first several neighbors: 0.00000 0.00000 0.00000 0 As1 0.00000 -0.46784 -0.12630 1.58774 4 O3_1 1.66004 -0.88804 -0.96644 -1.02986 4 O1_1 1.66830 1.65544 -0.19677 -0.19615 4 O2_1 1.67859 -0.36279 1.66519 -0.35929 4 O4_1 1.74171 -0.22909 1.88872 -1.29544 1 H1_1 2.30172 2.26346 1.49452 0.40642 1 H13_1 2.74263 2.03956 -2.01248 0.21917 1 H10_1 2.87366 1.14080 -0.11749 2.64281 1 H8_1 2.88092 2.08625 -0.17254 -2.02856 1 H5_1 2.91501 -2.72907 -0.44011 -1.05767 1 H9_1 2.95976 That looks more like what you were expecting.... B PS: The proper address for the mailing list is ifeffit@millenia.cars.aps.anl.gov rather than ifeffit-owner@... Mail to ifeffit-owner goes just to Matt and I rather than to the whole list. -- 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 My homepage: http://xafs.org/BruceRavel EXAFS software: http://cars9.uchicago.edu/~ravel/software/exafs/