Cover Image, Volume 113, Issue 1


original image

Shown on the cover is a recently reported iron(IV)-oxo complex with an (unusual) high-spin (S52) state. The correct description of multiplet states by theory is challenging as described in the Perspective by Marcel Swart on page on page 2. Different occupations of metal d-orbitals lead to different multiplet spin states, which are important for metal-oxo complexes, exchange-enhanced reactivity, spin-crossover and catalysis. Fortunately, recently some progress has been made towards understanding, and predicting, the drawbacks and successes of computational methods for these spinstate phenomena.