The energy surfaces of polymeric sulfur have been calculated with use of a parameter-free density-functional method. The authors study a wide range of geometries with interesting results. The calculated ground-state geometry is in good agreement with experiment, and the flat energy surfaces near this energy minimum are consistent with the extreme flexibility of the molecule. There are other geometries with energies only slightly above the ground-state energy, and stretching of the molecule results in metallic behavior.
 

Physical Review Letters, 57 1145-8, 1986.