dl-Methio­ninium dihydrogenphosphate

The asymmetric unit of the title compound, C5H12NO2S+·H2PO4−, contains two crystallographically independent methioninium residues and two dihydrogenphosphate anions. Pairs of cations and anions are linked by strong O—H⋯O hydrogen bonds. Head-to-tail chains running along the c axis of the unit cell are observed for both cationic residues. Alternate hydro­phobic and hydro­philic layers are observed parallel to the (010) plane.