The title compound, [1,3]dithiolo[4,5-d][1,3]dithiole-2,5-dione, C4O2S4, is
a sulfur heterocyclic system formally composed of a tetrathioethylene unit
(C2S4) and two carbonyl groups. The bicyclic molecule is essentially plana
r and exhibits D-2h symmetry, although the exocyclic-O atoms lie slightly [
+/- 0.128 (3) Angstrom] out of the plane through the five-membered 1,3-dith
iole (C3S2) ring.