Bis[5-oxo-4,5-dihydro-8H-2-azonia-4,8,9-trizabicyclo[4.3.0]nona-2,6,9(1)-triene] sulfate

In the crystal structure of the title compound, 2C5H5N4O+·SO42−, N—H...O hydrogen bonds assemble the molecules into a two-dimensional network structure parallel to the cb plane. The S atom of the sulfate ion lies on a special position on a twofold axis.