1. Consider a cube in which the central metal atom is placed at its centre (i.e., origin of the coordinate axis). The four ligands approach the central metal atom along the direction of the leading diagonals from the alternate comers of the cube.
2. In this field, the t2g orbitals (dxy , dyz and dzx) are pointing close to the direction in which ligands are approaching than the ‘eg’ orbitals. (dx2 – y2 and dz2).
As a result, the energy of t2g orbitals increases by 2/5 ∆t and that of ‘e’ orbitals decreases by 3/5 ∆t as shown in the figure. This splitting is inverted when compared to octahedral field.
