Disodium (2RS,3SR)-tartrate.

The asymmetric unit of the anhydrous title compound, 2Na(+)·C(4)H(4)O(6) (2-), contains two sodium cations and one tartrate anion. Each sodium ion is six coordinate, with bonding to six O atoms from both the carboxyl-ate and hydroxyl groups of the anion. A three-dimensional coordination network is formed with sodium ions stacking in layers along the c-axis direction. This network is supported by additional O-H⋯O hydrogen bonds.