[Ifeffit] Bug in Atoms

[Bruce Ravel]

On Tuesday 16 March 2004 08:32 am, Schmithals wrote:
> I have attached an atoms.inp file that causes problems when used with
> Artemis. Both, Atoms run from within Athena as well as TkAtoms generate
> a feff.inp file with a wrong POTENTIALS-Card. Subsequently, FEFF will
> refuse to run, saying that potential number 1 is not used.
> I tried the same procedure with an older atoms.exe and had no problems.

Hmmm.... I really should fix this problem.  I am surprised at how infrequently 
people complain about this problem.  I suppose that is why I haven't got 
around to doing so yet.

The problem is that Atoms does not check to make sure that every item in the 
potentials list is actually in the atoms list.  (I think the old fortran 
version did make that check, but it somehow never got in the new version.)  

If you make Rmax in Atoms bigger, the problem will go away because the cluster 
will then be big enough to include all the atoms in the potentials list.  If 
you do not want to compute feff on such a large cluster, just set Rmax in 
feff.inp to something appropriate.  

The error message in feff is trigered when a potential does not appear in the 
atoms list.  However, it is not required that each item in the potentials 
list appear within rmax of the central atom.  As a rule of thumb, I would 
recommend setting Rmax to something large-ish in Atoms and use feff's rmax to 
actually restrict the number of feffNNNN.dat files that you compute.


> Another bug: TkAtoms allows only to open the space group browser only
> once. Every further click on "Browse space groups" will have no effect.

No kidding?  I'll look into it when I get home from NSLS.


Thanks as always for the great bug reports, Gerrit.
B

-- 
 Bruce Ravel  ----------------------------------- ravel at phys.washington.edu
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