[Ifeffit] Ifeffit Digest, Vol 60, Issue 4

[joshua jason kas]

Another way to get feff to run is to define the stoichiometry. I found 
that the following cards work.

Change the SCF definition to the following

  SCF       3.46808   0      30     0.05

and change the potential definition to

  POTENTIALS
  *   ipot   z [ label   l_scmt  l_fms  stoichiometry ]
        0   26    Fe     -1      -1       1
        1   26    Fe     -1      -1       1000
        2   29    Cu     -1      -1       1

This makes feff assume that there are many Fe atoms for each Cu atom, 
which was what I was assuming from your feff.inp.
Cheers,
Josh

> Message: 1
> Date: Thu, 21 Feb 2008 13:52:31 -0600
> From: "Matt Newville" <newville at cars.uchicago.edu>
> Subject: Re: [Ifeffit] problem with feff.inp
> To: "XAFS Analysis using Ifeffit" <ifeffit at millenia.cars.aps.anl.gov>
> Message-ID:
> 	<b8522e3d0802211152p6fa9c908v24ba67bc2dfc81b2 at mail.gmail.com>
> Content-Type: text/plain; charset=ISO-8859-1
>
> It looks like the SCF calculation is having a hard time with the new
> potential.   The input file you sent only has atoms out to 2.48 Ang
> (though perhaps you truncated it when posting???), but the
>
>   SCF 4 0 30 0.2 1
>
> in your feff.inp means to make a self-consistent potential out to 4
> Ang.  Without any atoms out that far, I can imagine it would have
> problems.    I think you'll probably need a larger cluster than a
> single shell for a reasonable XANES simulation.
>
> Hope that helps,
>
> --Matt
>