Crystallization of the completely deuterated glycine silver nitrate (DGSN) from D₂O gave a new polymorph with the crystal structure significantly differing from that of the nondeuterated form (GSN): space group P21/c with polymeric two-dimensional layers parallel to the ab plane. In DGSN, the silver ions are mono-nuclear, whereas in GSN Ag–Ag dimers are present. In contrast to GSN, DGSN does not undergo any phase transitions on cooling at least till 100 K.