I understand that the complex [Re2Cl8]2- has a bond order of 4 between the ruthenium ions. The bond comprises of sigma interactions between Dz2 orbitals, two sets of pi interactions between dxz and d yz, and delta interactions between the dxy orbitals of the two ruthenium ions. My textbook says that the dx2-y2 orbitals remain for the metal ligand bonding. How do you fit 16 electrons from 8 ligands into two orbitals, I thought you could only fit two electrons in an orbital. Are the dx2-y2 orbitals forming hybrid orbitals with the empty 4s orbitals ?