Bruce,
 
I checked that the same problem existed for the original FEFF601.f fortran file in UNIX. I looked for the string "np > np1x" and found that the code stops when this condition is true. np1x is a fixed parameter defined in the code as parameter (np1x = 12000). When np (the paths counter) becomes 12001 (it is incremented in the code as the paths are counted), the code stops. Apparently, for this structure it happens for rmax exceeds 6.6 . When rmax = 6.6, the number of paths is less than 12000, and the code does not stop. I do not know why 12000 was chosen as a threshold... we can ask Alex.Therefore, if you have access to the feff6 source that is used in IFEFFIT (I assume you do), you can increase the np1x and recompile.
Regards,
 
Anatoly
 

******************
Anatoly Frenkel, Ph.D.
Associate Professor
Physics Department
Yeshiva University
245 Lexington Avenue
New York, NY 10016

(YU)  212-340-7827
(BNL) 631-344-3013
(Fax) 212-340-7788

anatoly.frenkel@yu.edu
http://www.yu.edu/faculty/afrenkel

-----Original Message-----
From: ifeffit-bounces@millenia.cars.aps.anl.gov [mailto:ifeffit-bounces@millenia.cars.aps.anl.gov]On Behalf Of Bruce Ravel
Sent: Friday, June 10, 2005 3:43 PM
To: XAFS Analysis using Ifeffit
Subject: [Ifeffit] odd feff6 behavior



Hi,

Here's a feff6 curiosity.  Take this atoms.inp file:

  title = TiN
  space = 225
  a =       4.24173       b =       4.24173       c =       4.24173
  core =  Ti      edge =  K       rmax =    7.0
  atoms
  ! elem   x          y          z    
    Ti    0.00000    0.00000    0.00000
    N     0.50000    0.50000    0.50000


Run atoms, then run feff6l (the one that comes with Ifeffit, it's the only
version I've tried this with).  Feff ends with this error message:
    Eliminating path degeneracies...
       Plane wave chi amplitude filter   2.50%
      np, np1x=    12001   12000
    Fatal Error: at PATHSD: np > np1x

This message comes from pathsd.f, but I don't understand either the message or
the part of the code it comes from.  Does anyone else have a hint as to the
problem?

One more datum.  If you reduce rmax to 6.7 in the atoms.inp file, the problme
persists.  If you make rmax 6.6, feff6l is happy.

Thanks,
B


--
 Bruce Ravel  ----------------------------------- bravel@anl.gov  -or-
                                                  ravel@phys.washington.edu
 Environmental Research Division, Building 203, Room E-165
 Argonne National Laboratory                        phone: (1) 630 252 5033
 Argonne IL 60439, USA                                fax: (1) 630 252 9793

 My homepage:    http://feff.phys.washington.edu/~ravel
 EXAFS software: http://feff.phys.washington.edu/~ravel/software/exafs/

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