The title compound, C4H4N6O5, crystallizes in the monoclinic space group P2
(1)/n, and is an energetic compound containing only C, H, N, and O with a d
ensity of 1.919 Mg m(-3). Among other reasons, this remarkably high density
is attributed to an extensive system of intra- and intermolecular hydrogen
bonds which results in a packing scheme involving zigzag sheets.