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Step 1 : Follow explanation for fitting a
quadrupolar line shape... to position a second order broadened line-shape at
the location of the distributed line.
Step 2 : Change Model
to CzSimple, put d to 5, em to -200 (typical) and recompute the model spectrum.
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Computation remains rapid until you put the FWHM CS value to non 0.
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Adjust the
em value to suppress spikes or wiggles
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Optimise
 the
physically relevant parameters
 :
amplitude, Position, FWHM CS, nuQ
Step 3 : Reporting integrated intensities
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The "CZSimple" Model :
The "CzSimple" model implements a rapid version of the Czjzek
distribution of quadrupolar interaction for the distribution of the isotropic
chemical shift (Gaussian Isotropic Model for d=5) with an uncoupled distribution
of isotropic chemical shift. See our paper in
Geochimica Acta or the
following references for use of this model.
The CzSimple model takes the following parameters :
 Amplitude
: vertical scaling factor
Position
: Istotropic average value
FWHM
CS : Full Width at Half Maximum of the isotropic chemical shift gaussian
distribution.
EM au
: line broadening used to smooth the discontinuities issued from the sampling of
nuQ/etaQ and diso, use she smallest possible value and do not allow
optimisation. Take negative values for gaussian apodisation. This is just a
cosmetic parameter.
nuQ
: Peak value of the quadrupolar coupling of the Czjzek/GIM distribution
(proportional to sigma values reported latest versions >2008)
d
: critical exponent of the Czjzek distribution, take d=5 for GIM, other values
do not have physical sense even if they give better rendering.
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