dl-Asparaginium nitrate.

In the title compound, C(4)H(9)N(2)O(3) (+)·NO(3) (-), alternatively called (1RS)-2-carbamoyl-1-carboxy-ethanaminium nitrate, the asymmetric unit comprises one asparaginium cation and one nitrate anion. The strongest cation-cation O-H⋯O hydrogen bond in the structure, together with other strong cation-cation N-H⋯O hydrogen bonds, generates a succession of infinite chains of R(2) (2)(8) rings along the b axis. Additional cation-cation C-H⋯O hydrogen bonds link these chains into two-dimensional layers formed by alternating R(4) (4)(24) and R(4) (2)(12) rings. Connections between these layers are provided by the strong cation-anion N-H⋯O hydrogen bonds, as well as by one weak C-H⋯O inter-action, thus forming a three-dimensional network. Some of the cation-anion N-H⋯O hydrogen bonds are bifurcated of the type D-H⋯(A(1),A(2)).