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Re: XANES for benzene



On Thursday 05 August 2004 05:11 pm, Alex Ankudinov wrote:
> I attacehed the feff.inp file and the output of the feff8.2 for that file.
> I modified your input file and changed many cards. I also like the
> ATOMS program to make feff.inp files, but typically I do not use the
> defaults and modify cards a lot. Here are the changes I made

Hi!

I was interested by Alex's response to the question about benzene and
wanted to make a comment.

I anticipated that the defaults in Atoms would not work for every
situation and so, when I rewrote Atoms from scratch 5 years ago, I
wrote a fairly flexible and generic system for writing output file.
This system is used by TkAtoms and Artemis as well as by the command
line version of atoms.  If you install the Ifeffit package, you will
get all those tools.

All output files in Atoms are formatted using special template files.
For Feff8, the file feff8.atp is used.  This file is installed when
the rest of Ifeffit (and Atoms!) are installed.  On Windows, this file
is found in C:\Program Files\Ifeffit\atp\.  On Unix it'll be in some
location like /usr/lib/perl5/site_perl/5.8.1/Xray/atp/ (or wherever it
got installed on your system).

You can edit this file and change the defaults.  Or you can copy it to
another name and use either set of defaults to format your output.
This is all explained in the atoms document.

In any case, if you find it tedious to always have to make the same
changes to a feff.inp file after running atoms, it will be well worth
your time to spend a few minutes modifying your copy of the template
file.  You can change the template once and have that change propagate
through to all future feff.inp files.

I have attached a copy of an atp file that I modified to be much
closer to the feff.inp file that Alex attached to his email.  (It's no
more than a plain text file.)

B


-- 
 Bruce Ravel  ----------------------------------- ravel@phys.washington.edu
 Code 6134, Building 3, Room 405
 Naval Research Laboratory                          phone: (1) 202 767 2268
 Washington DC 20375, USA                             fax: (1) 202 767 4642

 NRL Synchrotron Radiation Consortium (NRL-SRC)
 Beamlines X11a, X11b, X23b
 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/

<com> This file is part of the Atoms distribution.
<com> Atoms is copyright (c) 1998-2001 Bruce Ravel
<com> This is the atoms template file for a feff8 input file
<com> Atoms homepage: http://feff.phys.washington.edu/~ravel/software/atoms/
<com> This file is distributed under the terms of the Artistic License
<com>
<meta :precision 9.5 :file "feff8 input file" :output "feff.inp">
<meta :feff 8 :list "cluster" :sphere 2.2 :occupancy 0>

<id :prefix " * ">

<titles :prefix " TITLE ">

 *  <central> <edge> edge energy = <eedge> eV
 EDGE      <edge>
 S02       1.0

 *         pot    xsph  fms   paths genfmt ff2chi
 CONTROL   1      1     1     1     1      1
 PRINT     1      0     0     0     0      0

 *         ixc  [ Vr  Vi ]
 EXCHANGE  2  0  0

 * the next lines follow Alex's suggestions from the FEFFUSERS mailing
 * list
 AFOLP     1.4
 DEBYE     100 400

 *         r_scf  [ l_scf   n_scf   ca ]
 SCF       3.5

 *         kmax   [ delta_k  delta_e ]
 XANES     4.0

 *         r_fms     l_fms
 FMS      <rss>  0

 *         emin  emax   eimag
 LDOS      -30   20     0.1

 RPATH     0.1
 *EXAFS     20

<com> the stoichiometry counts the number of each potential in the
<com> unit cell, but does NOT divide out the greatest common denominator
 POTENTIALS
 *    ipot   Z  element            l_scmt  l_fms   stoichiometry
<com> styles are species, tags, and sites
<potentials :ipots species :gcd 0>
        <ipot>   <znum>   <elem>         <l>       <l>       <stoi>

 ATOMS                          * this list contains <nclus> atoms
 *   x          y          z      ipot  tag           distance
<list :style cluster>
  <x>  <y>  <z>  <ipot>    <tag>  <r>  <inc>
 END