CFSE Calculator
Notes:
- Tetrahedral and trigonal bipyramidal complexes are typically high spin.
- Square planar complexes are typically low spin (large Δ).
- Trigonal bipyramidal uses standard splitting energies relative to Δ_tbp (≈ Δ₀).
- Pairing energy is approximate (extra pairs relative to high-spin spherical field).
Must Read Crystal Field Lab
CFSE Reference Table (in Δ units, excluding pairing energy P)
| dn | Octahedral High Spin |
Octahedral Low Spin |
Tetrahedral (High Spin) |
Square Planar (Low Spin) |
Trigonal Bipyramidal (High Spin) |
|---|---|---|---|---|---|
| d⁰ | 0 | 0 | 0 | 0 | 0 |
| d¹ | -0.400 | -0.400 | -0.600 | -0.456 | -0.164 |
| d² | -0.800 | -0.800 | -1.200 | -0.912 | -0.328 |
| d³ | -1.200 | -1.200 | -0.800 | -1.368 | -1.144 |
| d⁴ | -0.600 | -1.600 | -0.400 | -1.824 | -0.872 |
| d⁵ | 0 | -2.000 | 0 | -2.280 | -1.688 |
| d⁶ | -0.400 | -2.400 | -0.600 | -2.736 | -1.416 |
| d⁷ | -0.800 | -1.800 | -1.200 | -2.092 | -2.232 |
| d⁸ | -1.200 | -1.200 | -0.800 | -2.548 | -1.960 |
| d⁹ | -0.600 | -0.600 | -0.400 | -1.904 | -1.688 |
| d¹⁰ | 0 | 0 | 0 | -1.360 | -2.036 |
Square planar values approximate Δ_sp ≈ 1.23 Δ₀. Trigonal bipyramidal values use standard relative energies (in units of Δ_tbp).