Hi folks, I released a new version of Atoms today which includes one small (but possibly important) change from the previous version. I learned that the database entry for a specific space group (I -4 3 d, #220) was in error. I fixed this and made a new release. There is a new tarball and Windows executable on my web site. If you are a windows user, you will also need to install the new version of the space_group.db file, as per the instructions on the downloads page. I also updated WebAtoms on Matt's server. This error has ABSOLUTELY NO IMPACT on any other space group. Indeed, without an atoms input file using the affected space group, you would never notice the problem. This underscores an interesting aspect of crystallography. While group theory tells us that there are 230 possible space group, nature seems to prefer using only a small subset of them. Indeed, in all the years since I started working on Atoms, I have not seen an example of a crystal in this space group until this week. The collection of input files that I distribute with Atoms for the purpose of testing the code includes examples of less than 80 space groups. Anyway, here is the input file that lead me to the error in Atoms' space group data base: title = Cu3As Domeykite title = Iglesias, J. E., and Nowacki, W., title = Zeitschrift fur kristallographie, kristallgeometrie, title = kristallphysik, kristallchemie, v. 145, pp. 334-345 (1977). space = I -4 3 d a = 9.6190 core = Cu rmax = 8.0 atoms ! elem x y z Cu -0.02930 0.12020 0.18760 As -0.02980 -0.02980 -0.02980 One might notice that the old Fortran version of Atoms handles this input file correctly. The irony of that is not lost on me, particularly in light of my frequent and loud trumpeting of the advantages of the new version over the old version. Thanks to Elspeth Barnes for bringing this problem to my attention. Regards, B -- Bruce Ravel ----------------------------------- ravel@phys.washington.edu Code 6134, Building 3, Room 222 Naval Research Laboratory phone: (1) 202 767 5947 Washington DC 20375, USA fax: (1) 202 767 1697 NRL Synchrotron Radiation Consortium (NRL-SRC) Beamlines X11a, X11b, X23b, X24c, U4b 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/
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Bruce Ravel