The splitting pattern of d orbitals in octahedral field:

The separation between the t2g and eg levels is conventionally represented by Δ° or 10 Dq.
Module 3 : Coordination Chemistry
Lecture 5 : Valance Theory of coordination complexes and Crystal-field Theory
The splitting pattern of d orbitals in octahedral field:

The separation between the t2g and eg levels is conventionally represented by Δ° or 10 Dq.