Seitenhistorie

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1. different lineshapes (if the peak height and not the peak volumes were taken)
2. differences in the starting Z-magnetisation (beginning of the NOE mixing time) due to incomplete relaxation between the scans
3. differences in the starting Z-magnetisation due coherent transfer through other nuclei, such as in HSQC-NOESY.

This normalization is not final for those peaks stemming from multiplet(s) N₁ x N₂ of equivalent spin groups 1 and 2. In such cases, the average normalized buildup (-->σ_i,j) is obtained by further multiplication by (N₁ x N₂)^^(1/2) /(N₁ x N₂). (See the full formula below.)

b:

The step above  makes the cross-relaxation rates σ_i,j in a correct mutual proportion. The actual values can be still inaccurate due to inaccurate reference distance, r_Ref in Eq. 1, or rather σ_Ref being not correctly proportional to the r_Ref  due to spin diffusion or other effects. It is therefore recommendable to correct the median of the measured distances such that it corresponds to the distances conserved among these organic molecules: around 4.2 Å for intramolecular distances and 4.4 Å for the intermolecular distances. When correcting the derived distances, we include a constant to multiply the distances in order to obtain the desired median.

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• Calculate the normalized NOE buildups,  by dividing the original ones by the geometric mean of the diagonal decays and factor due to their possible multiplicity (Q pseudoatoms):
  _NOEij,Norm= NOE_ij/(Decay_i*Decay_j)^^(1/2)  x (N₁ x N₂)^^(1/2) /(N₁ x N₂)
  The tables "diagonal peaks intensities of the ligand (autorelaxation)" are conveniently sorted for this task.

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