title: Redetermination of cytosinium hydrogen maleate-cytosine (1/1) from the original data.
abstract: The title salt, C4H6N3O(+)·C4H3O4 (-)·C4H5N3O, has been redetermined from the data published by Benali-Cherif, Falek & Direm [Acta Cryst. (2009), E65, o3058-o3059]. The improvement of the present redetermination consists in the discovery of the splitting of one of the H atoms into two disordered positions, the occupancies of which are equal to 0.55 (2) and 0.45 (2). These H atoms are involved in an N⋯N hydrogen bond and are shifted towards its centre. The disorder of these H atoms is in agreement with a similar environment of the two independent, but chemically equivalent, cytosinium/cytosine mol-ecules.
authors.affiliation: Inst. of Physics of the Czech Academy of Sciences, Na Slovance 2, 182 21 Praha 8, Czech Republic.
authors.forename: Jan
authors.initials: J
authors.lastname: Fábry
keywords: Cambridge Structural Database; crystal structure; hydrogen bonding; redetermination; refinement constraints; refinement restraints