[Ifeffit] atoms possible bugs

[George Sterbinsky]

Hello,

I want to make everyone aware of some bugs that I think I have found in
atoms, and pose some questions regarding the bugs, to anyone who may have
seen them before.

I have attached two atoms input files, generated using the Artemis atoms
interface. The file A2n_atoms.inp is for a monoclinic structure in the A 2/n
setting. On running atoms, one will find that there are six Ga atoms within
a 4 A radius from the central Ga atom. If one reduces the the cluster size
from 8 A in the .inp file to 6 A, one finds that now there are only two Ga
atoms within 4 A of the central Ga atom. So it appears that atoms does not
necessarily include all atoms within the cluster radius. The leads me to the
question: how big should I make the cluster if I want to include all atoms
within 6 A?

An input file for the same structure converted to the C 2/c setting is also
attached. When running atoms in the Artemis interface, the message "The axis
lengths and angles specified are not appropriate for the given space group"
is returned. Although, it appears that a Feff.inp file is still generated.
It also appears to not have the same cluster size dependence as the A2/n
structure. So can I trust this feff.inp file even though I received an error
message? It seems to me that the answer would be yes, atoms did the
calculations correctly and the error message being generated is just a bug,
but I'm not certain about this.

Thank you,
George
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20110510/da77923a/attachment.html>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: C2c_atoms.inp
Type: application/octet-stream
Size: 695 bytes
Desc: not available
URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20110510/da77923a/attachment.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: A2n_atoms.inp
Type: application/octet-stream
Size: 696 bytes
Desc: not available
URL: <http://millenia.cars.aps.anl.gov/pipermail/ifeffit/attachments/20110510/da77923a/attachment-0001.obj>