Fitting static CSA spectrum...
31P spectrum fitted with CSA static model
CSA Parameters :
principal values are sorted |d33-diso|>|d11-diso|>|d22-diso|
diso is the isotropic chemical shift 1/3 (d33+d22+d11)
dCS is the axiality of the CSA tensor (d33-diso)
etaCS is the anisotropy of the CSA tensor etaCS=(d22-d11)/(d33-diso)
Definitions in agreement with Simpson (Aarhus)
M.Bak, J.T.Rasmussen, N.C.Nielsen J. Magn. Reson. 147 296-330 (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.
From a CSA MAS :
Just change the model from CSA MAS to CSA static
From scratch :
Initiate a fit
Add a line
Changte the mode to CSA Static
Enter CSA parameters or Drag the line on screen (you can adjust amplitude, position and axiality of the tensor.
Step 2 : Optimize the parameters
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.
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]
Line Parameters (Bold parameters are selected for
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.
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.