Space-filling model of the lysergic acid diethylamide (LSD) molecule, C₂₀H₂₅N₃O.

Colour code:

• Carbon, C: grey-black
• Hydrogen, H: white
• Nitrogen, N: blue
• Oxygen, O: red

Structure based on that found in the related salt LSD o-iodobenzoate monohydrate, determined by X-ray crystallography in Molecular Pharmacology (1973) 9, 23-32 (CSD entry LSDIBZ01; an earlier determination, LSDIBZ, is also recorded in the CSD).

Model manipulated in CrystalMaker 8.3.

The structure of the [LSD+H]⁺ cation from the above crystal structure was opened in Spartan Student 4.1, one hydrogen atom on the R₃NH⁺ group was deleted, yielding the neutral LSD molecule. Its structure was then refined with the PM3 semi-empirical method.