Crystal structure of tri-methyl-ammonium 5-(2,4-di-nitro-phen-yl)-1,3-dimethyl-2,6-dioxo-1,2,3,6-tetra-hydro-pyrimidin-4-olate.

The asymmetric unit of the title mol-ecular salt, C3H10N(+)·C12H9N4O7 (-) [alternative name: tri-methyl-ammonium 5-(2,4-di-nitro-phen-yl)-1,3-dimethyl barbiturate], contains one anion and two half-occupancy cations. The cations are disordered about inversion centres. The tetra-hydro-pyrimidine ring is essentially planar [maximum deviation = 0.007 (2) Å] and forms a dihedral angle of 41.12 (6)° with the plane of the benzene ring. In the crystal, N-H⋯O hydrogen bonds link the cations to the anions.