Bis(4-amino-pyridinium) dichromate(VI).

The asymmetric unit of the title salt, (C5H7N2)2[Cr2O7], contains four independent cations and two independent dichromate anions. The crystal structure consists of discrete dichromate anions with an eclipsed conformation stacked in layers parallel to (010) at y = 1/4 and y = 3/4. These layers are linked via 4-amino-pyridinium cations by N-H⋯O and weak C-H⋯O hydrogen bonds, forming a three-dimensional supra-molecular network. In addition, π-π inter-actions are present in this structure; the shortest distance separating mean planes through 4-amino-pyridinium cations is 3.679 (6) Å.