EXAFS Solids
From FEFF
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Cu metal
Cu, fcc metal, 4 shells. The list of atomic coordinates (ATOMS card) for crystals can be produced by the program atoms. Thus instead of giving long atoms list, we present a short ‘atoms.inp’ file. For connection with EXAFS fitting programs see FEFF Files and the PRINT card.
TITLE Cu crystal, 4 shells * Cu is fcc, lattice parameter a=3.61 (Kittel) *Cu at 190K, Debye temp 315K (Ashcroft & Mermin) DEBYE 190 315 0 POTENTIALS 0 29 Cu0 1 29 Cu ATOMS atoms list generated using atoms.inp file below -------------------------------------------- title Cu metal fcc a=3.6032 fcc ! shorthand for F M 3 M rmax= 11.13 a=3.6032 out=feff.inp ! index=true geom = true atom ! At.type x y z Cu 0.0 0.0 0.0 --------------------------------------------
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YBCO High-Tc superconductor
TITLE YBCO: Y Ba2 Cu3 O7 Cu2 core hole CONTROL 1 1 1 1 1 1 PRINT 0 0 0 0 0 0 RPATH 4.5 POTENTIALS * ipot z tag 0 29 Cu2 1 8 O 2 39 Y 3 29 Cu1 4 56 Ba ATOMS atoms list generated by the following atoms.inp file ----------------------------------- title YBCO: Y Ba2 Cu3 O7 (1-2-3 structure) space P M M M rmax=5.2 a=3.823 b=3.886 c=11.681 core = Cu1 atom ! At.type x y z tag Y 0.5 0.5 0.5 Ba 0.5 0.5 0.184 Cu 0 0 0 Cu1 Cu 0 0 0.356 Cu2 O 0 0.5 0 O1 O 0 0 0.158 O2 O 0 0.5 0.379 O3 O 0.5 0 0.377 O4 --------------------------------------
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Calculation Strategies and Examples
EXAFS calculations
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