FullCalculator

Crystal Field Splitting Calculator

Δ from Absorption Wavelength

Calculate crystal field splitting energy from the wavelength of maximum absorption

CFSE from d-Electron Count

Calculate Crystal Field Stabilization Energy for a given d-electron count

Formula

Δ = hc/λ | Δ_tet ≈ (4/9)Δ_oct | CFSE = Σ(electrons × orbital energy) | μ = √(n(n+2)) BM

Frequently Asked Questions

What is crystal field splitting?
Crystal field splitting (Δ or 10Dq) is the energy difference between sets of d-orbitals caused by the electrostatic field of surrounding ligands. In octahedral complexes, d-orbitals split into lower t₂g and higher eg sets. The size of Δ determines color, magnetism, and stability.
What determines high spin vs low spin?
If the crystal field splitting Δ is larger than the electron pairing energy P, electrons pair up in lower orbitals (low spin). If Δ < P, electrons spread across all orbitals before pairing (high spin). Strong-field ligands (CN⁻, CO) favor low spin; weak-field ligands (I⁻, Br⁻) favor high spin.
Why is tetrahedral splitting smaller?
Tetrahedral splitting Δ_tet ≈ (4/9)Δ_oct because fewer ligands interact less directly with the d-orbitals. This is why tetrahedral complexes are almost always high-spin — the splitting is too small to overcome pairing energy.

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