Table 2. Experimental details.

Crystal data
Chemical formula	C4H6N3O+·C4H3O4 −·C4H5N3O
M r	338.29
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	298
a, b, c (Å)	27.3226 (5), 7.3618 (2), 14.6742 (4)
β (°)	93.905 (1)
V (Å3)	2944.77 (13)
Z	8
Radiation type	Mo Kα
μ (mm−1)	0.13
Crystal size (mm)	0.3 × 0.15 × 0.1
Data collection
Diffractometer	Nonius KappaCCD
No. of measured, independent and observed [I > 3σ(I)] reflections	3490, 3474, 2367
R int	0.043
(sin θ/λ)max (Å−1)	0.661
Refinement
R[F 2 > 3σ(F 2)], wR(F 2), S	0.038, 0.093, 1.85
No. of reflections	3474
No. of parameters	246
No. of restraints	2
H-atom treatment	H atoms treated by a mixture of restrained and constrained refinement
Δρmax, Δρmin (e Å−3)	0.20, −0.20

Computer programs: KappaCCD Server Software (Nonius, 1998 ▸), DENZO and SCALEPACK (Otwinowski & Minor, 1997 ▸), SIR2004 (Burla et al., 2005 ▸), PLATON (Spek, 2009 ▸) and JANA2006 (Petříček et al., 2014 ▸). Extinction correction: Becker & Coppens (1974 ▸).