nmrAna

nmrAna is a Matlab-based tool for analysis of nuclear magnetic resonance (NMR) measurements. The program allows to analyse the entire series of measured spectra as a function of temperature and other parameters like Tau in case of spin-lattice time (T₁) measurements.

Authors

Anton Potočnik (IJS, F5)
Andraž Krajnc (KI)
Peter Jeglič (IJS, F5)
Tomaž Apih (IJS, F5)

Features

Automatic fast fourier transform from FID with auto phase and auto SHL option.
Analysis of T₁ and T₂ measurements with fitting of magnetization curves (fminsearch)
Analysis of pulse-length optimization measurements (D₁)
Analysis of frequency sweep measurements
Linescan analysis (e.g. analyse T₁ over the spectra line)
Spectral component fitting using entire magnetization recovery measurements
Extraction of spectra from magnetization recovery measurements
Spectral moment analysis
Plot of various experimental parameters

Analytical functions are defined in separate files, so one can easily add new functions or change the existing ones.

Recognized file formats

In-house 7NMR file format
Andraž Krajnc developed conversion tool from Bruker NMR data files to 7NMR format

Screen shot

: Spin-lattice time analysis

Source Code

Distributed under GNU GPL license. If the analysis obtained by this tool is going to be published in any journal, the authors are required to cite this webpage.

https://github.com/apotocnik/nmrAna

Documentation

FFT parameters

SHL shift left (index)

PH phase (radians)

autoSHL = 0, 1, 2, 3

0: the SHL value,

1: mean of autoCorrInd values

2: individual SHLall(:,2) from FID

3: weighted (0-1) SHL average according to SPC intensity and above threshold defined by CUT

4: fitted SHL values from previous analysis using first order polynomial

autoPH = 0, 1, 2, 3, 4

0: the PH value,

1: mean of autoCorrInd values

2: individual phiall(:,2) from FID

3: weighted (0-1) phi average according to SPC intensity and above threshold

4: fitted phase values from previous analysis using second order polynomial

autoPH_SPC = 1,2,3

1: mean of autoCorrInd values from the spectre at PH_v freq

2: correct from SPC phase at PH_v freq

LB exponential (Lorentzian) line broadening (Hz)

SI time domain (number of FFT points, must be 2^n)

DE = 0,1 double echo

TURN = 0,1 invert frequency axis (required for 380 MHz spectrometer)

autoCorrInd = 1:5 vector of sorted indeces that are used for auto correction

avrPoints number of FID data points around SHL used to calculate mean Phase.

range = [left right] range in Hz for plotting spectra stack

Dy y-spacing between spectra in the stack
PH_v central frequency for autoPH_SPC
LIM = [left right] integration limits for T1, T2, … analysis

CUT lower value for weighted SHL linear fit

Spectrum parameters

REF reference frequency in MHz
isPPM = true/false convert to ppm
ppmRange = [left right] nParams = [-left right ampl] range and amplitude parameters
range = [nParams(1) nParams(2)] (ppm or kHz)

NORM Normalization
0: multiply spectrum with nParams(3)
1: divide spectrum by maximal value and multiply it with nParams(3)
2: divide spectrum by maximal value within the range and multiply it with nParams(3)
3: divide spectrum by area within the range and multiply it with nParams(3)
4: multiply spectrum with temperature and nParams(3)
otherwise: multiply spectrum with 1

spcSumInd = [1:5] sum spectra at ordered indeces specified in vector
CUT2 cutoff for moment analysis

Fitting parameters

SIMtype = ‘T1-1mS’ fitting function, see available functions by pressing SIMtype button
Niter number of iterations
indFIT = [1] define vector of limits for fitting. If LIM has more raws indFIT vector can choose which to fit
allinitpar vector of initial parameters. By pressing CP button, allinitpar are substituted by the latest fitting results
allresetpar vector of reset parameters. By pressing RP button, allinitpar is substituted by allresetpar
indFitpar vector of parameter indeces to fit. Parameters with indeces not listed here are kept fix.
Trun = {‘[1/T1/T]ylog’, ‘delta’, ‘[alpha]’} special description of plotted parameters as a function of temperature at the end of Run analysis.

Sweep spectra parameters

SUMdelta frequency step in MHz of summed spectrum
Fmin left cutoff in kHz in summed spectrum
Fmax right cutoff in kHz in summed spectrum
Lmin, Lmax left and right cutoff in kHz for each individual spectrum

Weights (S) are calculated from Spectra between min(LIM) and max(LIM). After running Sweep, weights are calculated from Spectra between Lmin and Lmax.

For more information or bug report please contact me.

Tagged under: NMR, tools

Anton Potočnik - research website

Anton Potočnik