To calculate the magnetic moment of Ni CO 4, we first need to determine the electronic configuration of the central metal ion Ni and the ligands CO in the complex.Ni is a transition metal with an atomic number of 28. Its ground state electronic configuration is [Ar] 3d^8 4s^2. In Ni CO 4, Ni is in the +0 oxidation state, so its electronic configuration remains the same.CO is a strong field ligand and forms a -donor and -acceptor bond with the metal ion. In this case, the molecular orbital theory also known as Ligand Field Theory is more appropriate to use than the crystal field theory.According to the molecular orbital theory, the five 3d orbitals of Ni and the ligand orbitals form bonding and antibonding molecular orbitals. The -donor interaction of CO with Ni leads to the formation of a2g and t2g orbitals, while the -acceptor interaction leads to the formation of eg* orbitals.The electronic configuration of Ni in Ni CO 4 is [Ar] 3d^8. The eight d-electrons will fill the molecular orbitals as follows:1. Three t2g orbitals are filled with six electrons two electrons per orbital .2. One a2g orbital is filled with two electrons.All the d-electrons are paired in the molecular orbitals, and there are no unpaired electrons. Therefore, the magnetic moment of Ni CO 4 is zero. This result indicates that Ni CO 4 is diamagnetic, which means it has no net magnetic moment and does not interact with an external magnetic field.