VSEPR theory
High oxidation states of the metal are dictated by the fact that oxygen is a strong oxidizing agent, as is fluorine. Bromine and iodine are relatively weak oxidizing agents, so fewer oxobromides and oxoiodides are known. Structures for compounds with d0 configuration are predicted by VSEPR theory. Thus, CrO2Cl2 is tetrahedral, OsO3F2 is trigonal bipyramidal, XeOF4 is square pyramidal and OsOF5 is octahedral. The d1 complex ReOCl4 is square pyramidal.