Fitting CSA Magic Angle Spinning sideband partterns...
Example :
31P spectrum fitted with CSA MAS model 3kHz
Example :
31P spectrum fitted with CSA MAS model 6kHz
Example :
31P spectrum fitted with CSA MAS model 15kHz
Example :
13C 200MHz Glycine spectrum 5.033kHz MAS
Example :
13C 200MHz Glycine spectrum 1.940kHz MAS
Example :
13C 200MHz Glycine spectrum 0.962kHz MAS
Example :
MAS spectrum with both QUAD & CSA
CSA Parameters :

principal values are sorted d33diso>d11diso>d22diso

diso is the isotropic chemical shift 1/3 (d33+d22+d11)

dCS is the axiality of the CSA tensor (d33diso)

etaCS is the anisotropy of the CSA tensor etaCS=(d22d11)/(d33diso)
Definitions in agreement with
Simpson (Aarhus)
M.Bak, J.T.Rasmussen, N.C.Nielsen J. Magn. Reson. 147 296330 (2000)
It is assumed that you know how to fit Gaussian/Lorentzian lines to a spectrum
There exist several possible strategies... the following describes a possible one.
Step 1 : Define the N=0 isotropic lines and the spinning
sidebands

Locate the N=0 spinning sideband (using other spinning rate,
prior knowledge or whatever...)

Add
a line or Drag
an existing one to this position with the
[Gauss/Lor] model

Add
a new line and change its
model to [ss band] mode

Fill in the two new boxes that appeared in the [Fit
Pannel] : spinning sideband number [+/1, 2..] & reference line number [N=0
band that has just been set]

Click
the [Drag] button and
position the spinning sideband (amplitude and pos), the position & spinning
sideband number will update the spinning rate value.

Click

repeat operation from 3 for all the spinning sidebans that you
want to use

Save your work, just in case [Menu/Decomposition/Save Fit] or
[Menu/Decomposition/Save As Fit]
Step 2 : Optimize the parameters

Click
the [Parameters] button to call the [Model Parameters
full list] dialog and add a star at the right of the spinning rate to allow
its optimization, quit the dialog box.

Click
the [Optimize] button to
optimize the current solution optimizing Amp/Pos/Width of the ref line, Amp only
for the spinning sidebands, and spinning rate.

Save your work, just in case [Menu/Decomposition/Save Fit] or
[Menu/Decomposition/Save As Fit]
Step 3 : Retrieve CSA parameters
You can whether export the table of intensities using
the [Report] button and submit this table
intensity to other software you rely on
or
estimate the CSA parameters (from precomputed tables) with the
dmfit program :

Click
the [Parameters] button to call the [Model Parameters
full list] dialog

Select one of the spinning sideband, a button labeled
[CSA ??] will appear above

Click this button to look the tables for the better
match.

A dialog box shows up with the better solution taking
into account all the spinning sidebands defined

If you want you can click the [ssb > mCSA] button to
transform the set of spinning sideband to a single contribution under [CSA mas]
model.

Quit and recompute
the model spectrum.

Save your work, just in case [Menu/Decomposition/Save
Fit] or [Menu/Decomposition/Save As Fit]

Remark 1 : Change the spinning rate and
recompute to model the spectrum for another spinning rate value if you like to

Remark 2 : you can switch from [CSA mas]
model to set of spinning sideband by calling
the [Model Parameters
full list] dialog and clicking the [Explode] button.
Warning : this procedure only provides you with
a guess of the CSA parameters, not a real optimized measurement.
Line Parameters (Bold parameters are selected for
automatic optimization):
Amplitude : height of the maximum of the N=0 line
Position : Isotropic Position of the N=0 line (in Hertz, ppm or point depending on the current
unit) positions of the spinning sidebands are given by their numbers, the
position of the reference line and the spinning rate.
Width : full width at half maximum of the line an its spinning
sidebands
xG/(1x)L : Gaussian/Lorentzian ratio (1 for Gaussian, 0 for Lorentzian)
(shared by all the lines of the spinning sidebands maniflod)
dCS : the axiality of the CSA tensor (in Hertz, ppm or point
depending on the current unit)
etaCS : the assymetry paramter of the CSA tensor.