Strychnine has been used widely as a test molecule for the establishment and validation of NMR experiments. In the present context, the HNMR spectrum of strychnine (Figure ) demonstrates two frequently encountered properties that require careful terminological consideration for proper interpretation: visual multiplicity pattern mismatch and peak overlap. The resonance of H-18b gives rise to a peak pattern that apparently does not match the expected (first-order) multiplicity of the two strongly and one weakly coupled nucleus. The customary determination of the peak distances in this apparent yet illogical ddd-type pattern quickly reveals that they cannot be aligned with the geometries such as the relative dihedral angles as calculated via the Karplus relationships in this relatively constrained alicyclic molecule.