In the title solvated mol-ecular salt, 2C4H12N5 (+)·CO3 (2-)·2CH3OH, the complete carbonate ion is generated by crystallographic twofold symmetry, with the C atom and one O atom lying on the rotation axis. The cation is twisted about the central C-N bond [C-N-C-N = -137.7 (6)°]. In the crystal, the components are linked by N-H⋯O, N-H⋯N and O-H⋯O hydrogen bonds, generating a three-dimensional supra-molecular network.
Keywords: crystal structure; hydrogen bonding; metformin; sodium carbonate.