The crystal structure of N2O5.3SO3

The crystals of N~O5.3S08 are monoclinic, with a = 19.54,b = 7.30, c = 7.56 A, fl = 102 °.Systematic absences lead to space groups C2/c or Cc.Although intensity statistics would indicate a center of symmetry, no normal structure in the space group C2/c could be found.On the other hand, it was possible to derive a set of atomic coordinates with symmetry Cc with strong pseudosymmetry which introduces a false center in one of the projections.The structure consists of NOa and $3010 groups, in agreement with the interpretation of Raman spectra.