What is meant by crystal field splitting energy ? On the basis of crystal field theory, write the electronic configuration of `d^(4)` in terms of `t_(2g)` and `e_(g)` in an octahedral field when
`Delta_(0)gtP`

Explanation

The five d-orbitals in a metal ion are degenerate (of equal energy). But when ligands approach the central metal ion, they experience repulsions. The d-orbitals are split into two groups consisting of three orbitals called `t_(2g)` orbitals and two orbitals called `e_(g)` orbitals. the `e_(g)` orbitals possess greater energy than`t_(2g)` orbitals. Till there are three electrons, they will occupy three `t_(2g)` orbitals singly. If there are 4 electrons in d-orbitals i.e., `d^(4)` configuration, two cases arise.
If `Delta_0 gt P`, then the fourth electron will go to `t_(2g)` orbital, the electronic configuration will be `t_(2g)^(4)e_(g)^(0)` .