Calculating Crystal Field Stabilization Energy (CFSE)
To calculate the Crystal Field Stabilization Energy (CFSE) of a transition metal complex, you can follow these steps:

Determine the oxidation state of the metal:
Identify the metal ion and determine its oxidation state in the complex. This information will help you understand the electronic configuration of the metal ion.

Identify the ligands:
Determine the type and number of ligands surrounding the metal ion in the complex. Different ligands will lead to different crystal field splitting patterns.

Assign the d-electron configuration:
Based on the metal ion's oxidation state and the type of ligands, assign the d-electron configuration of the metal ion. This will help you determine how the d-orbitals are split in the crystal field.

Calculate the CFSE:
Use the crystal field splitting diagram to determine the energy levels of the d-orbitals in the complex. Calculate the energy difference between the high energy and low energy sets of d-orbitals to obtain the Crystal Field Stabilization Energy (CFSE).

Sum up the CFSE values:
Calculate the total CFSE by summing up the CFSE values for each d-electron in the complex. This will give you an idea of the overall stability of the complex based on the crystal field effects.
By following these steps, you can calculate the Crystal Field Stabilization Energy (CFSE) of a transition metal complex and understand how the arrangement of ligands affects the stability of the complex.

Cfse = -0.4x + 0.6y where x = electrons in t2g. while y = eg..