Molecular orbital theory for octahedral complexes

In the crystal field treatment of complexes, the interaction between the central metal ion and the ligands is taken to be purely electrostatic, i.e., ionic bonding. If 

Relative effects of spin-orbit coupbng and octahedral crystal field interaction on the electronic state 4D. 

A coordinate system for MLg, where the ligands have only a to bond with the metal ion. 

We first treat those complexes that have only a metal-ligand bonding. Examples of this type of complexes include [M(H20)6] + and [M(NH3)6] +, where M + is a first transition series metal ion and a typical n value is either 2 or 3. A coordinate system for such a complex is shown in Fig. 8.8.1. The representation generated by the six ligand orbitals is 

Linear combinations of a ligand orbitals matching symmetry with the atomic orbitals on the central metal ion in ML6- 

---

A molecular orbital theory for octahedral / complexes is described. It is pointed out that the neglect of covalent bonding in the analysis of optical data for the actinide complexes is not justified, and that its inclusion leads to orbital reductions which are considerably greater than have usually been assumed. 

---