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1D NMR line shapes




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Source code

This is a summary of all folders relevant to line shape analysis. See my lecture notes on theory of line shape analysis in Mathematical_models/NMR_line_shape_models/1D/My_lectures.



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Specific line-shape models

Specific models for one-dimensional NMR line shapes are defined by modules in code/+line_shape_equations_1D/ and included in the body of  NMRLineShapes1D class (code/@NMRLineShapes1D/NMRLineShapes1D.m). Below is brief outline of the existing models, their purpose and capabilities. For a rigorous way of deriving them see Mathematical_models/NMR_line_shape_models/1D/.




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A workflow for introducing a new model






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Experimental NMR line shapes are extracted from 2D HSQC spectra using a custom extension IDAP 1D NMR in Sparky spectral analysis software (obtain Sparky from The IDAP 1D NMR extension is written in Python and described in Sparky_extension.

Important considerations on data acquisition and processing:

  1. Spectra must be prepared using Exponential Multiply apodization window (EM in NMRPipe). Bloch-McConnell equations describe lorentzian signals therefore any other apodization windows are not acceptable.
  2. If the heteronuclear spectrum was obtained using a constant-time experiment---the indirect dimension line shapes are (most likely) not useful because there was no free "induction decay" collected due to constant-time acquisition mode of t1. Experiments like that are most frequently performed to record proton-carbon correlations.
  3. Zero-filling must be adjusted to have about 5-10 data points per signal envelope (above baseline). More points only overload CPU but do not add any new information. Fewer points make fitting much less stable.


A subclass of NMRLineShapes1D called BiophysicsLab_1D_NMR.m enables import the exported spectral slices into a TotalFit session.



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