Glycyl-L-alanine: a multi-temperature neutron study

Neutron diffraction data have been collected at 12, 50, 150 and 295 K for the dipeptide glycyl-L-alanine in order to obtain accurate positional and anisotropic displacement parameters for the H atoms. The values of these parameters serve as a benchmark for assessing the equivalent parameters obtained from a so-called Hirshfeld-atom refinement of X-ray diffraction data.

The self-assembling zwitterionic form of L-phenyl­alanine at neutral pH

The zwitterion of L-phenyl­alanine was characterized using synchrotron X-rays. It crystallized in the monoclinic space group P2₁ with four mol­ecules in the asymmetric unit. The 0.62 Å resolution structure was obtained in the same configuration as that assumed to be adopted in the self-assembly of nanotubes.