[Ifeffit] [Fwd: FEFF Q]

[Matt Newville]

Hi Ryan,

feff.inp doesn't have much more than a list of x,y,z coordinates
for the atoms in the cluster, so if you have these you are most
of the way there!

What you really need is a set of coordinates: x,y,z,ipot
where ipot is an index (0 through 7) that identifies a unique 
atomic Potential: you'll need a different one for each atomic 
species, and a special one (the one marked 0) to signify the 
absorbing atom. 

feff.inp also needs the list of atomic Potentials.  I'd start
with a feff.inp generated from Atoms (or Artemis) for a crystal
and edit from there.  You'd just need to alter the Potentials
and Atoms sections.  Note that the central atom is denoted by
IPOT=0, not as the atom at x=y=z=0, though that is convenient.  
For simulated clusters, that means you might be able to make
many feff.inp files simply by selecting different atoms to be
the central atom.

Is that enough of a start or do you need more hints? 

--Matt