FEFF Documentation

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Abstract


FEFF9 is an ab initio self-consistent multiple-scattering code for simultaneous calculations ofexcitation spectra and electronic structure.The approach builds in core-hole effects and can include local fields (TDLDA). Output includes extended x-ray-absorption fine structure (EXAFS), full multiple scattering calcula-tions of various x-ray absorption spectra (XAS) and projected local densities of states (LDOS).The spectra include x-ray absorption near edge structure (XANES), x-ray natural and magnetic circular dichroism (XNCD and XMCD), spin polarized x-ray absorption spectra (SPXASand SPEXAFS), non-resonant x-ray emission spectra (XES), the x-ray scattering amplitude(Thomson and anomalous parts), and electron energy loss spectroscopy (EELS).This work has been supported in part by grants from the U.S. Department of Energy and bythe University of Washington Office of Technology Transfer. FEFF is copyright © 1992–2009,The FEFF Project, Department of Physics, University of Washington, Seattle, WA 98195-1560.

This wiki version of the FEFF9 documentation was last updated January 2012. Generally, the pdf version of the documentation is the most accurate and most up-to-date source of information on FEFF9.


Contents

Synopsis

Acknowledgements and history

The FEFF Users Guide

Tutorial


Calculating Material Properties with FEFF

General Comments

Running FEFF

Calculating the potential and phase shifts

Calculating the Density of States

Calculating the Multiple Scattering Green's function

EXAFS calculation

  1. SF6 Molecule
  2. Solids
  3. Estimate of S_{0}^{2}
  4. Configuration averaging over absorbers
  5. Adding self-consistency

XANES calculations

  1. Need for SCF and additional difficulties for XANES
  2. GeCl4 Molecule
  3. Solid: XANES and LDOS
  4. Absolute cross-section

Spin dependent calculations

  1. General description
  2. XMCD for the Gd L1 edge
  3. SPXAS

Elastic Scattering Amplitudes

X-ray Emission Spectra XES

Calculation of EELS

  1. Running FEFF for EELS
  2. Changing EELS parameters
  3. EELS Files
  4. Example Input Files

NRIXS Calculation

  1. Some Example Input
  2. Limitations and practicalities

Local Field and Core-hole Effects (PMBSE, TDDFT)

K-space FEFF

  1. Notes on using a .cif file
  2. Using the file reciprocal.inp
  3. Converging the k-mesh
  4. EXAFS and EXELFS
  5. Using crystal symmetry
  6. Speed
  7. Example Input Files

Charge Transfer and Charge Counts

Ab initio Debye-Waller factors

  1. EM and RM methods
  2. DM methods

Parallel Computing

Cloud Computing

Using the Many-Pole Self Energy (MPSE)


FEFF9 Control Cards

The ‘feff.inp’ file

Complete list of FEFF9 control cards

Structural Information Cards

Spectrum Information Cards

FEFF Program Control Cards

General Cards

ATOMIC, POT, SCREEN: Scattering potentials

XSPH: Cross-section and phase shifts

FMS and MKGTR: Full multiple scattering

PATH: Path enumeration

GENFMT: XAFS parameters

FF2X: XAFS spectrum

SFCONV: Spectral Function Convolution

EELS: Electron Energy Loss Spectrum


Input and Output Files

Data flow

File Reference

  1. Main output data
  2. Intermediate files
  3. Diagnostic files
  4. Variables in the EXAFS and XANES formulae

Program control using intermediate output files


(A) Copyright Information, Restrictions and License

(B) Installation Instructions

Installation

Compiling your own code

(C) References

(D) Code Variables and Dimensions

(E) Spin.f program for XMCD and SPXAFS

(F) Technical notes for dynamical matrix based Debye-Waller factors

(G) Trouble-Shooting FEFF Problems and Bug Reports

developer's resources