Tables generated by FEFF (version 3.23)
File names are of the form FEFFsrr.zz where
s = K or L, K for K shell absorption, L for LIII shell absorption
rr = 20 or 30, 20 for 2.0 Angstroms near neighbor distance
30 for 3.0 Angstroms near neighbor distance
zz is the atomic number, always 2 digits.
Example: FEFFK20.29 K shell absorption for copper,
rnn = 2.0 angstroms
Example: FEFFL30.82 LIII shell absorption for lead,
rnn = 3.0 angstroms
The title line of the table begins with i) the element symbol, ii) the
reference used to determine the structure to use when calculating
potentials, and iii) the neighbor distance used to calculate the
potential (labelled "rpot"). The remainder of the title line
describes the exchange correlation used (Hedin-Lundquist) and
the version of FEFF used to create the table.
Lines 2 and 3 describe the absorbing and neighboring atom
sizes. Rmt is the muffin tin radius, Rnm is the Norman radius.
The fourth line contains Rnn, the distance used to calculate the
Feff data. This is not necessarily the same as the distance used for the
potential calculation. Sigma2 is the Debye-Waller factor which is set to
zero for these tables, S02 is an amplitude reduction factor, set
to 1.0. Gam_ch is the core hole lifetime (gamma core hole) for the
central atom, is calculated by FEFF.
The last header line contains interstitial parameters. Mu is the
Fermi energy, Kfermi is the Fermi momentum, Vint is the potential
in the interstitial region, and Rs is the radius of a sphere whose
volume contains one electron at the interstitial electron density.
A sample header and tabulated data is listed below:
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Cu Kittel rpot=2.553 H-L exch FEFF 3.23
Central Z=29, Nnn=12.00, Rmt=1.2910E+00, Rnm=1.4416E+00, Ion= 0 K shell
Neighbor Z=29, Nnn=12.00, Rmt=1.2620E+00, Rnm=1.4092E+00, Ion= 0
Rnn= 2.00000E+00, Sigma2= 0.00000E+00, S02 = 1.00000E+00, Gam_ch= 1.76125E+00
Mu =-5.50945E+00, Kfermi= 1.79507E+00, Vint=-1.77864E+01, Rs_int= 2.02036E+00
k real(2*phc) mag(feff) phase(feff) red factor lambda real(p)
.000 3.4857E+00 0.0000E+00 -6.1597E+00 .9870E+00 1.5543E+01 1.7962E+00
.200 3.4879E+00 4.9948E-02 -6.9494E+00 .9874E+00 1.5635E+01 1.8069E+00
.400 3.4938E+00 9.0724E-02 -7.7216E+00 .9886E+00 1.5909E+01 1.8385E+00
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These tables are based on potentials of the atoms in a typical structure
for a monatomic solid. If you are interested in a material that is
much different from the configuration in the tables, you may get better
results by running the FEFF program for that situation. (These tables
are in the same form as the optional output file FEFF.DAT.)
References used for configurations:
Kittel "Introduction to Solid State Physics", 6th edition,
Tables 3 and 4.
Slater "Quantum Theory of Molecules and Solids, Volume 2"
Wyckoff "Crystal Structures", 4th edition Volume 1
Tabulated data:
k momentum wrt fermi level k=sqrt(E-mu)/0.529
k is in inverse Angstroms; E, mu in Rydbergs
real(2*phc) twice real part of central atom phase shift
mag(feff) backscattering curved wave amplitutde
phase(feff) backscattering curved wave phase
red factor absorbing atom reduction factor
lambda mean free path = 1/(Im (p)), where p is local
momentum. lambda is in Angstroms.
real(p) real part of local momentum p (inverse Angstroms)
For additional details see feff.doc, the documentation file attached to
program FEFF (attached below as an appendix).
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Appendix: feff.doc
c-----------------------------------------------------------------------
c
c program feff (version 3.23)
c
c Note: input file has changed slightly compared with earlier
c versions; see notes below
c
c calculates single-scattering, curved wave xafs spectra,
c phase shifts and effective scattering amplitudes
c for arbitrary pairs of atoms throughout the
c periodic table (Z < 95)
c
c features: code uses a relativistic dirac-fock-slater desclaux
c atom code with the von barth-hedin ground state lda
c exchange correlation potential; scattering states are
c calculated using overlapped atom potentials (mattheiss
c prescription) plus a hedin-lundqvist complex exchange
c correlation potential for excited states, referenced
c to the averaged interstitial potential; muffin-tin
c radii are determined automatically from calculated
c norman radii; xafs spectra are referenced to the
c threshold fermi level, as determined by electron gas
c theory; atomic configurations and core-hole lifetimes
c are built in, and mean free paths are determined from
c the imaginary part of the avg interstitial potential
c
c machine requirements: double precision (real*16) version
c
c code is written in ANSI FORTRAN 77
c except that complex*16 variables are required
c
c a single precision version for CRAY and CDC machines is also
c available from the authors
c
c input: feff.inp (see samples listed below and notes)
c
c output: chi.dat (and other files depending on print level)
c
c NOTE: delete or rename old chi.dat and other.dat files
c prior to running
c
c
c Sample input files: (6 lines)
c
c Subscript 0 refers to the absorbing atom, 1 to the backscatterer
c Distances are in Angstroms. Default entries are 0 or 0.0. For
c further details see the notes below.
c
c Copper K-shell 300K So**2=1. (title)
c 29 29 1 Z0, Z1, hole-code (atomic #'s, hole-code)
c 2.5526 12.0 12.0 rnn, nnn0, nnn1 (near-neigh dist, coord #'s)
c 0.00793 1.0 sigma2, s02 (DW and amplitude red. factors)
c 1 0 iprint, runflag
c 0 0 0 0.0 0.0 index_xc, ion0, ion1, folp, gamach
c
c SF6, 10% overlapping muffin-tins (title)
c 16 9 1 Z0, Z1, hole-code
c 1.56 6.0 1.0 rnn, nnn0, nnn1
c 0.001729 1.0 sigma2, s02
c 1 1 iprint, runflag
c 0 0 0 1.1 0.0 index_xc, ion0, ion1, folp, gamach
c
c Description of input:
c First line of this input file is the title of the run.
c For parameters for which defaults are available, input of zero will
c get the default.
c Z0, Z1 Atomic numbers of absorbing and scattering atoms
c hole code 1 - K shell absorption
c 2 - LI shell
c 3 - LII shell
c 4 - LIII shell
c rnn Near neighbor distance (Angstroms)
c nnn0, nnn1 Coordination number of absorbing and scattering atoms
c sigma2 Debye-Waller factor
c s02 Amplitude reduction factor
c iprint 0 - chi.dat only
c 1 - add misc.dat, save.dat
c 2 - add feff.dat
c ... (see below)
c 10 - all .dat files
c runflag 0 - Complete FEFF run using this input file
c 1 - Calculate only final EXAFS results from previously
c calculated potentials and phase shifts. Read rnn,
c sigma2 and s02 from FEFF.INP, all phase shifts,
c etc., from SAVE.DAT. Useful if you want to
c modify Debye-Waller factor or rnn somewhat.
c 2 - Used to generate standard tables of FEFF
c scattering amplitudes, phase shifts, etc., same as
c feff.dat (currently disabled)
c folp Overlapping muffin tins. folp=1.1 is 10% overlap, etc.
c gamach Core-hole width (eV). 0.0 for default (recommended)
c index_xc 0 - Hedin-Lundquist exchange correlation potential
c 1 - Dirac-Hara
c ion0, ion1 Ionization of absorbing and scattering atoms.
c
c print output file file contents
c level
c
c 0 Standard xafs data chi(k) relative to threshold (angstroms)
c
c chi.dat k, chi(k), |chi(k)|, ph(chi) (xafs)
c
c 1 Data to run calculation of chi, etc. only -- useful if
c only Debye-Waller factor, S02 or small changes to rnn are
c necessary.
c
c save.dat phase shift data (binary file)
c misc.dat file header, used to identify run
c
c 2 Effective scattering amplitude and phase shift data, with k
c referenced to threshold
c
c feff.dat k, phi_c, |feff|, ph(feff),
c so**2, lambda, Re(p)
c
c 3 Theoretical curved wave xafs data for chi(p) relative to
c the muffin-tin zero (atomic units)
c
c feffcw.dat k, 2*real(delta_c), |fth|, ph(fth),
c so**2, Re(p), Im (p)
c
c 4 Theoretical plane wave xafs data for chi(p) relative to
c the muffin-tin zero (atomic units)
c
c feffpw.dat k, 2*real(delta_c), |fpw|, ph(fpw),
c so**2, Re(p), Im (p)
c
c 5 atom.dat atom ground state data
c
c 10 phase.dat atomic phase shifts
c
c variables:
c
c k = wave number (ang**-1); k=sqrt(e-e_f) where
c e is energy and e_fermi is the fermi level
c computed from electron gas theory at the
c avg interstitial charge density
c chi(k) = so**2 * nnn0 * (|feff|/kR**2) * exp(-2R/lambda)
c * exp(-2k**2*sigma**2) * sin(2kR + ph(feff) + phi_c))
c (curved wave K or L-shell xafs function)
c phi_c = 2*delta_l_c -l*pi (total central atom phase)
c feff = effective, curved-wave backscattering amplitude
c feff(k) in xafs formula
c ph(feff) = phase of feff(k)
c fth = theoretical effective backscattering amplitude
c fth(p) = (k/p) feff(k) exp(2i (p-k) R)
c so**2 = S0**2*exp(-2 imag (delta_c) )
c total central atom loss factor
c R=rnn = near neighbor distance
c nnn0 = mean number of near neighbors to central atom
c sigma**2 = mean square variation of R
c lambda = mean free path (angstroms) =-1./imag (p)
c kf = fermi momentum at avg interstitial charge density
c p=p(r) = local momentum (p(r)**2=k**2+kf(r)**2+sigma-sigma_f)
c sigma = self energy at energy e, sigma_f at energy e_f
c
c
c Plotting output: utilities available from authors for
c ibm pc's, TopDrawer, conversion to UW XAFS format
c
c main authors: j. mustre de leon, university of washington*
c *present address: los alamos national labs
c s. i. zabinsky, university of washington
c r. c. albers, los alamos national labs
c j. j. rehr, university of washington
c
c if problems are encountered in using these codes, please
c contact us at the following e-mail and telephone numbers:
c
c j. j. rehr jjr@uwaphast.bitnet (206) 543 8593
c r. c. albers rca@nidhug.lanl.gov (505) 665 0417
c j. mustre de leon mustre@meediv.lanl.gov (505) 665 4008
c s. i. zabinsky zabinsky@uwaphast.bitnet (206) 543 0435
c
c please acknowledge the use of these codes:
c
c a long description is being prepared for physical review b
c citation: j. mustre de leon, j.j. rehr, and r.c. albers.
c a brief description will be submitted to j. am. chem. soc.
c by j. mustre de leon, j.j. rehr, r.c. albers, and s. zabinsky.
c a published reference to the original version is: j.j. rehr,
c r.c. albers and j. mustre de leon, physica b158, 417 (1989).
c
c restrictions: these programs are being made available for
c scientific investigations only; to maintain consistency, new
c users should request the latest version of this code from the
c authors.
c the code is NOT intended for commercial use. those interested
c in any commercial application should contact the authors
c for a licensed version.
c
c acknowledgements: early versions of the exchange-correlation
c codes were written by d. lu; a. djaoui assisted with the
c complex version of the phase program; the atomic code is a
c automated version of the desclaux code (see subroutine atom)
c we also thank many users of early versions of this code,
c especially, m. benfatto, s. cramer, c.r. natoli, d. sayers,
c e.a. stern, and t. tyson for comments and suggestions.
c
c version 1.0 (*) preliminary versions of atom,
c phase, and ssk xafs codes
c * see subroutines for dates
c
c version 2.0 (9 aug 89) unified atom,phase,xafs codes
c 2.1 (13 sep 89) modified output format
c
c
c version 3.0 (14 feb 90) new version with overlapping atom
c potential and muffin-tin finder
c
c version 3.1 (28 mar 90) four-point integration added for
c potentials, minor coding changes
c to enhance portability
c
c version 3.23 (24 jul 90) minor bugs fixed, ability to run
c ssk via save.dat file added
c
c--------------------------------------------------------------------
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Copyright information:
Tables prepared by Steven Zabinsky and John Rehr, Dept. of Physics, Univ.
of Washington.
J. Rehr jjr@leonardo.phys.washington.edu (206) 543 8593
S. Zabinsky zabinsky@uwaphast.bitnet (206) 543 0435
Table version 1.0 (24 oct 90) initial release
FEFF tables copyright 1990 by the FEFF project at the University of
Washington. Please see citation information above. A license for
these tables may be obtained by writing to FEFF Project,
c/o Marion Joyner, Dept. of Physics, FM-15,
Univ. of Washington, Seattle, WA 98195. Tel: (206) 685-2400
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