Crystal data for α-iminodiacetic acid

The α form of iminodiacetic acid, HN(CH₂COOH)₂, C₄H₇NO₄, is found to be orthorhombic, space group Pb2₁a. The lattice parameters of the unit cell with eight molecules are a₀ = 14.172 (7), b₀ = 14.977 (8) and c₀ = 5.276 (3) Å. The crystals melt with decomposition at 520 (2) K. X-ray powder diffraction data are reported.