title  Ni[CN]4 : molecule atoms in average positions 
title  see Inorganic Chemistry
title  A. Munoz-Paez, S. Diaz-Moreno, E. Sanchez-Marcos, JJ Rehr

format = ascii
rspout = yes	qspout = yes	kspout = yes
all = yes

% bkg = true
% bkgfile = fits/nicn4k.background
% bkgfile = fits/solidk.background

data = data/solidk.chi
% data = data/complexk.chi
out = fits/nicn4    # solid
kmin = 3.0	kmax = 15	dk = 1	kw = 3
rmin = 1.2	rmax = 3.5
cormin = 0.4

%==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==

guess	s02		1.0

guess	e0N		5.0
set	e0C		e0N

guess	sigC		0.004
guess	sigN		0.0053

set	sigmm		0.00054

%% This model (and the use of the collinear, average length feff
%% calculation) ignores internal disorder and so yields values of
%% deltaR and sigma^2 which contain systematic error.  The error in
%% sigma^2 could be backed out using temperature data, but the error
%% in delta_R (and the effect of bond angle) require more sphisticated
%% modelling). 
guess	deltaR_C	0.0
guess	deltaR_N	0.035

%==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==+==



%% There are two single scattering paths, Ni-C and Ni-N

path	1	feff/feff0001.dat
id	1	Ni-C2 SS, deg=4.000, r_eff=1.87
e0	1	e0C
s02	1	s02
sigma2	1	sigC + sigmm
delr	1	deltaR_C

path	2	feff/feff0002.dat
id	2	Ni-N2 SS, deg=4.000, r_eff=2.994
e0	2	e0N
s02	2	s02
sigma2	2	sigN + sigmm
delr	2	deltaR_N


%% these are the 3- and 4-legged paths involving Ni-C-N

path	3	feff/feff0003.dat
id	3	Ni-C2-N2-Ni, deg=8.000, r_eff=2.994
e0	3	(e0N+e0C) / 2
s02	3	s02
sigma2	3	sigN + sigmm
delr	3	deltaR_N

path	4	feff/feff0004.dat
id	4	Ni-C2-N2-C2-Ni, deg=4, r_eff=2.994
e0	4	(e0N+2*e0C) / 3 
s02	4	s02
sigma2	4	sigN + sigmm
delr	4	deltaR_N


%% These paths are 3- and 4-legged paths involving the C2 atoms on
%% either side of the central atoms.  These are colinear, but smaller
%% than the paths above

path	5	feff/feff0006.dat
id	5	Ni-C-C-Ni, deg=4.000, r_eff=3.6794
e0	5	e0C
s02	5	s02
sigma2	5	2*sigC + sigmm
delr	5	2*deltaR_C

path	6	feff/feff0007.dat
id	6	Ni-C-Ni-C-Ni, deg=4.000, r_eff=3.6794
e0	6	e0C
s02	6	s02
sigma2	6	2*sigC + sigmm
delr	6	2*deltaR_C

path	7	feff/feff0008.dat
id	7	Ni-C-Ni-C-Ni, deg=4.000, r_eff=3.6794 
e0	7	e0C
s02	7	s02
sigma2	7	4*sigC + sigmm
delr	7	2*deltaR_C



%% this last one is a triangle path Ni-C-C-Ni
%% we can safely ignore this one

% path	8	feff/feff0005.dat
% id	8	amp=5.613, deg=8.000, nleg=3, r_eff=3.1675
% e0	8	e01
% s02	8	s02
% sigma2	8	sig_ + sigmm
% delr	8	deltaR_



!!&& Local Variables:
!!&& input-k-weight: "3"
!!&& input-out-path: "fits/"
!!&& input-feff-path: "feff/"
!!&& input-data-path: "data/"
!!&& input-program-name: "feffit"
!!&& End:
%# Input-mode Time-stamp: <2000/05/19 14:42:30 bruce>