Relaxation via Chemical Shielding Anisotropy

When other relaxation mechanisms compete with dipolar relaxation (often the case, as we see subsequently), the magnitude of rj is reduced according the fraction of the total relaxation rate represented by the dipolar contribution  

As with dipolar relaxation, the interaction energy for CSA (in this case from Eqs. 6.3 and 7.17) enters quadratically, leading to the following expression for an axially symmetric shielding tensor in the extreme narrowing limit  

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