...
c:
- find out how many spins (NSpinsfrom each site contribute to the final crosspeak (NSigma = N1*N2) contribute to each NOE signal. For cross-peak between two methyl groups, NSigma = 3*3 = 9. The normalisation averaged them such that these distances are approximately the physical ones. Divide those distances by NSpins^NSigma^(1/6) to obtain shorter distances for cross-peaks originating in multiple spins, as expected by CYANA.
...