What is crystal field stabilization energy (CFSE) ?

The crystal field stabilization energy (CFSE) in [Co(SCN)_(6)]^(3-) is :

The crystal field stabilization energy (CFSE) in [Co(SCN)_(6)]^(3-) is :

The magnitude of crystal field stabilization energy (CFSE) in tetrahedral complexes is considerably less than in the octahedral field beause

The total crystal field stabilization energy (CFSE) for the complexes [Co(H_(2)O)_(6)]^(3+) and [CoF_(6)]^(3-) are respectively : (P is the pairing energy)