# FEFF Output files

## Main output data

### chi.dat’

Standard XAFS data containing k, χ(k), | χ(k) | relative to threshold (k = 0). The header also contains enough information to specify which model was used to create this file.

### ‘xmu.dat’

The file ‘xmu.dat’ contains both XANES and XAFS data μ, μ0, and $\tilde{\chi}=\chi\,\mu_0/\mu_0(\mbox{edge + 50eV})$ as functions of absolute energy E, relative energy E − Ef and wave number k.

### ‘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.

### ‘feffNNNN.dat’

You have to use the PRINT option to obtain these files. Effective scattering amplitude and phase shift data, with k referenced to threshold for shell nn: k, φc, | Feff | , φeff , the reduction factor, λ, Re(p).

If you need these, use the PRINT option for FF2X greater than or equal to 3, which will read ‘feff.bin’ and write the ‘feffNNNN.dat’ files in exactly the form you’re used to.

### ‘fpf0.dat’

Thomson scattering amplitude f0(Q) and constant contribution to f’ from total energy term.

### ‘ratio.dat’

Ratio μ0(E), ρ0(E) and their ratio versus energy, for XMCD sum rules normalization.

### eels.dat'

This contains the EELS spectrum: energy loss in eV, total spectrum, contribution from each component of the cross section tensor.

### magic.dat'

This file is only written if the MAGIC card is used. It contains the collection angle in rad, the pi to sigma ratio, the pi and sigma components of the spectrum, and the total spectrum.

## Intermediate output files

### ‘modN.inp’ and ‘ldos.inp’

These ASCII files contain basic information from ‘feff.inp’ for a particular module. They can still be edited, for example to take advantage of symmetries.

### ‘global.dat’

This ASCII file contains global information about x-ray polarization and about configurational averaging.

### ‘geom.dat’

This ASCII file contains Cartesian coordinates of all atoms and first-bounce information for the degeneracy reduction in the pathfinder.

### ‘pot.bin’

Charge density and potential (SCF or not) for all types of atoms. This file is used by the XSPH module.

### ‘phase.bin’

This is a binary file with the scattering phase shifts for each unique potential and with relativistic dipole matrix elements, normalized to total cross section in ‘xsect.bin’. It is used by the FMS, PATH and GENFMT modules.

### ‘xsect.bin’

Total atomic cross section for x-ray absorption. This is an ASCII file, but highly sensitive to format. Information can be viewed, but editing this file is not recommended.

### ‘ldosNN.dat’

l-projected density of sates for the NNth potential index (see the LDOS card)

### ‘fms.bin’

contains the results of FMS calculations. Used by FF2CHI to get total XAFS or XANES.

### ‘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 file by hand, see Section 3.3. (‘pathNN.dat’ files are also created during the LDOS calculations for each type of potential, but they are deleted after use.)

### ‘crit.dat’

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

### ‘list.dat’

List of paths to use for the final calculations. Written by GENFMT when the XAFS parameters are calculated and used by FF2CHI. It contains the curved wave importance ratios, which you may wish to study. For details on editing this by hand, see Section 3.3.

The curved wave importance ratios are the importance of a particular path relative to the shortest single scattering path.

### specfunct.dat'

This is a binary file containing the spectral function. If it is not present, sfconv will create it. Every time the material is changed, specfunct.dat' will be recomputed.

## Diagnostic files

### ‘phaseNN.dat’

Complex phase shifts for each shell.

### ‘phminNN.dat’

Real part of phase shifts for $\ell$=0,1,2 only. They are smaller versions of corresponding ‘phaseNN.dat’.

### ‘potNN.dat’

Detailed atomic potentials and densities.

### ‘atomNN.dat’

Diagnostic information on Desclaux free atom NN.

### FEFF Input and Output Files

Descriptions of output files