Redetermination of 3-methylbenzoic acid

The asymmetric unit of the title compound, C8H8O2, contains two crystallographically independent molecules, which form dimers linked by O center dot center dot center dot H-O hydrogen bonds. The benzene rings in the dimers are inclined at a dihedral angle of 7.30 (8)degrees and both methyl groups display rotational disorder. This redetermination results in a crystal structure with significantly higher precision than the original determination [Ellas & Garcia-Blanco (1963). Acta Cryst. 16, 434], in which the authors reported only the unit-cell parameters and space group, without any detailed information on the atomic arrangement. In the crystal, dimers are connected by weak C-H center dot center dot center dot O interactions, forming R-2(2)(10) and R-4(4)(18) rings along [110] and an infinite zigzag chain of dimers along the [001] direction also occurs.