(+-)-Tartaric acid.

(+-)-Tartaric acid, C(4)H(6)O(6), crystallized from ethanol in space group P 1 macro. The structure is characterized by five hydrogen bonds, including the formation of a centrosymmetric carboxylic acid dimer which forms infinite chains along the body diagonal. These chains form sheets via hydrogen bonding between alpha-hydroxyl groups. The sheets are connected through a bifurcated hydrogen bond. Structural comparisons are made with homochiral (2R,3R)-(+)-tartaric acid.