Previous Next Table of Contents

6. Chapter 6: Output files

6.1 phase.bin

This is a binary file with the scattering phase shifts for each unique potential. It is used by GENFMT and the pathfinder.

6.2 paths.dat

Written by the pathfinder, this is a description of all the paths that fit the criteria used by the pathfinder. It is used by GENFMT. The path descriptions include cartesian coordinates of atoms in the path, scattering angles, leg lengths and degeneracy. For details on editing this by hand, see section 4.

6.3 crit.dat

Values of the quantities tested against the various criteria in the pathfinder.

6.4 geom.dat

Written by feff for use with the pathfinder, and deleted after use. It is an atom list created from the user-input list in feff.inp. For more information, see the NOGEOM card in section 4.

6.5 list.dat

List of files to use to create chi.dat. Written by GENFMT when the xafs parameters are calculated and used by FF2CHI. This contains the curved wave importance ratios, which you may wish to study. For details on editing this by hand, see section 5.

The curved wave importance ratios are the importance of a particular path relative to the most important path encountered so far in the calculation. If the first path is the most important in the problem, all the importance factors will be expressed as a fraction of that path. However, if the third path considered is the most important, and the first path is the next most important, path 1 will have a factor of 100%, path 2 will be a fraction of the first path's importance, path 3 will have an importance of 100% (since it is now the most important path), and subsequent paths will be expressed as a percent of path 3's importance.

6.6 chi.dat

Standard xafs data k, chi(k), |chi(k)| relative to threshold (k=0): The header also contains enough information to specify what model was used to create this file.

6.7 feff.bin

A binary file that contains all the information about the XAFS from all of the paths. This replaces the old feffNNNN.dat files (which you can make using the PRINT card). If you want to use this file with your own analysis package, use the code in subroutine feffdt as an example of how to read it.

6.8 feffNNNN.dat

You have to use PRINT option to obtain these files. Effective scattering amplitude and phase shift data, with k referenced to threshold for shell nn: k, phi_c, |feff|, ph(feff), redfac, lambda, Re(p)

If you need these, use PRINT option for ff2chi greater than 3, which will read feff.bin and write the feffNNNN.dat files in exactly the form you're used to.

6.9 Diagnostic files from POTPH


misc.dat

Header file for quick reference.

phaseNN.dat

Complex phase shifts for each shell.

phminNN.dat

Real part of phase shifts for l=0,1,2 only.

potNN.dat

Detailed atomic potentials and densities.

atomNN.dat

Diagnostic information on Desclaux free atom NN.


6.10 xsect.bin, rkk.bin and xmu.dat files

Dipole matrix elements and absolute energies for XANES calculations. Note: the file xsect.bin does not contain the fermi-function cutoff at the edge, while xmu.dat does. Dipole matrix elements in rkk.bin normalized to the total cross-section in xsect.bin. The file xmu.dat contains both XANES and XAFS data mu, mu_0, and chi as functions of absolute energy E, relative energy E-e_f and wave number k.

6.11 Variables in output files and in calculation of XAFS


k

wave number (ang**-1); k=sqrt(e-e_f) where e is energy and e_f is the fermi level computed from electron gas theory at the avg interstitial charge density

chi(k)

s0ˆ2 * redfac sum_shells ( natsh * (|feff| /kR**2) * exp(-2R/lambda) * sin(2kR + ph(feff) + phi_c)) * exp(-2*k**2*sigma**2) )

phi_c

2*delta_l_c - l*pi (total central atom phase)

feff

effective curved-wave backscattering amplitude feff(k) in xafs formula for each shell

ph(feff)

phase of feff(k) for each shell

redfac

exp(-2 imag (delta_c) ), total central atom loss factor

R

distance to central atom for each shell

natsh

mean number atoms in each shell

sigma**2

mean square variation of R for each shell

lambda

mean free path (angstroms) =-1./imag (p)

kf

fermi momentum at avg interstitial charge density

p=p(r)

local momentum (p(r)**2=k**2+kf(r)**2+sigma-sigma_f)

sigma

self energy at energy e, sigma_f at energy e_f

mu

total absorption cross-section

mu_0

atomic background absorption



Previous Next Table of Contents