CQ4
  -OEChem-09132413073D

  5  4  0     0  0  0  0  0  0999 V2000
  -19.8210   12.6610  -27.1600 O   0  5  0  0  0  0  0  0  0  0  0  0
  -21.6760   11.0790  -28.5270 O   0  5  0  0  0  0  0  0  0  0  0  0
  -20.2380   11.9570  -28.6290 Cr  0  0  0  0  0  0  0  0  0  0  0  0
  -20.4950   13.1360  -29.7870 O   0  0  0  0  0  0  0  0  0  0  0  0
  -18.9680   10.9420  -29.1120 O   0  0  0  0  0  0  0  0  0  0  0  0
  3  4  2  0  0  0  0
  3  5  2  0  0  0  0
  2  3  1  0  0  0  0
  1  3  1  0  0  0  0
M  CHG  2   1  -1   2  -1
M  END
> <OPENEYE_ISO_SMILES>
[O-][Cr](=O)(=O)[O-]

> <OPENEYE_INCHI>
InChI=1S/Cr.4O/q;;;2*-1

> <OPENEYE_INCHIKEY>
ZCDOYSPFYFSLEW-UHFFFAOYSA-N

> <FORMULA>
CrO4-2

$$$$