Processing 3D NUS Data: A Step-by-Step Tutorial

This guide walks you through processing 3D NMR experiments recorded with higher percentages of Non-Uniform Sampling (NUS), typically 20% or higher (NusAMOUNT under ACQUPARS).

Step 1: Initial Processing Without Reconstruction

Given the sufficient NusAMOUNT used in 3D experiments, for efficiency you can process the data without reconstructing missing points to create projections for phase correction and strip transformation.

ftnd 0 nusft

Step 2: Create Projections for Phase Correction

For proton-detected experiments, set the STSR and STSI values in PROCPARS as described in the 3D phase correction tutorial.

Step 3: Set Processing Parameters

Ensure main processing parameters (edp) are correctly set in edp according to your spectrum type:

  F3 F2 F1
SI      
PHC0      
PHC1      
PH mod pk pk pk
BC_mod qfil or qpol no no
STSR      
SRSI      
FCOR      
NUS      
Mdd_mod cs    
MddF180   false false
MdPHASE   0 0

Optional: Increase Iterations

To improve reconstruction quality, increase the number of iterations:

Mdd_CsNITER 600

The following parameters are automatically set:

Step 4: Process with NUS Reconstruction

Process the spectrum with NUS reconstruction:

ftnd 0

Step 5: Optional Baseline Correction

For further refinement, perform baseline correction:

tabs3
tabs2
tabs1

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