title: 5-Amino-1,3,4-thia-diazol-2(3H)-one.
abstract: The asymmetric unit of the title compound, C(2)H(3)N(3)OS, contains three independent mol-ecules which are essentially planar, with r.m.s. deviations of 0.011 (2)-0.027 (2) Å from the mean plane defined by the seven non-H atoms. In the crystal, N-H⋯N and N-H⋯O hydrogen bonds link the mol-ecules into a sheet parallel to the (111) plane.
authors.affiliation: Department of Chemistry, Chungnam National University, Daejeon 305-764,  Republic of Korea.
authors.forename: Sung Kwon
authors.initials: SK
authors.lastname: Kang
authors.forename: Nam Sook
authors.initials: NS
authors.lastname: Cho
authors.forename: Siyoung
authors.initials: S
authors.lastname: Jang