Redetermination of tetra­methyl tetra­thia­fulvalene-2,3,6,7-tetra­carboxyl­ate

An improved crystal structure of the title compound, C₁₄H₁₂O₈S₄, is reported. The structure, previously solved using the heavy-atom method (R = 7.1%), has now been solved using direct methods. Due to the improved quality of the data set an R value of 2.06% could be achieved. In the crystal, C—H...S and C—H...O contacts link the mol­ecules.