Oxidation state (+III) of chromium (d3)
Cr3+ form unusual basic acetate, [Cr3O(CH3COO)6L3]+
where L is refered to H2O or other ligand.
Each Cr atom is octahedrally Surrounded by 6 atoms:
4 Oxygen atoms from 4 acetate groups, the central Oxygen atom and the ligand (L).