2,5-Dimethyl-1,3-dinitro-benzene.

The title compound, C(8)H(8)N(2)O(4), was prepared via the nitration of p-xylene. The mol-ecules are stacked along the c axis in an antiparallel manner. The two nitro groups are rotated relative to the benzene ring with dihedral angles of 44.50 (7) and 31.67 (8)°. The tilt of the nitro groups allows the formation of C-H⋯O inter-actions between the ring C-H and nitro groups of adjacent mol-ecules creating puckered sheets perpendicular to the c axis. The H atoms of the methyl group in the 5-position are disordered (60° rotation) with an occupancy of 0.616 (19) for the major component. The crystal was found to be a non-merohedral twin with a twin law [-1 -0.002 0.005, 0.00031 -1 0.002, 0.118 -0.007 1] corresponding to a rotation of 180° about the reciprocal axis (001) and refined to give a minor component fraction of 0.320 (2).