The asymmetric unit of the title compound, C 6H 5N 5·C 9H 6O 6, comprises a full mol-ecule each of neutral trimesic acid (tma) and zwitterionic 5-(pyridin-1-ium-3-yl)-5H-1,2,3,4-tetra-zol-5-ide (ptz). The components are linked into a two-dimensional layer by a combination of O - H⋯O, O - H⋯N, N - H⋯O and N - H⋯N hydrogen bonds parallel to the (10 ) plane. Layers comprising alternating rows of tma and ptz are linked into a three-dimensional network by C - H⋯O and π-π inter-actions between tma and tetra-zolate rings [centroid-centroid dis...
