Crystal field stabilization energy (CFSE) for octahedral high/low spin (Count electrons in t2g/eg with −0.4 and +0.6 in Δo units; subtract m×P for m new electron)
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Count electrons in t2g/eg with −0.4 and +0.6 in Δo units; subtract m×P for m new electron pairs forced by field
What each symbol means
| Symbol | What it stands for |
|---|---|
| P | Mean pairing energy |
| m | Extra pairs formed due to field vs free ion distribution |
| n_{eg} | Electrons occupying eg |
| n_{t2g} | Electrons occupying t2g |
When to use this
High spin: minimize pairing until necessary; low spin: maximize t2g occupancy if Δo > P for d⁴–d⁷.