Anatoly and Bruce: What value would you recommend for nplx? Carlo On Fri, 10 Jun 2005, Anatoly Frenkel wrote:
[Ifeffit] odd feff6 behaviorBruce,
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
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-----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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