Redetermined crystal structure of α-DL-me­thio­nine at 340 K

An accurate redetermination of α-DL-me­thio­nine provides coordinates for the H atoms, detailed hydrogen-bond geometries and reveals that the side chain is disordered over a major (95%) and a minor (5%) position.

Redetermined structure of β-DL-me­thio­nine at 105 K: an example of the importance of freely refining the positions of the amino-group H atoms

By refining positional coordinates for the three amino H atoms of a previously published amino acid structure, an improved structural model with shorter and more linear hydrogen bonds is obtained.