 Spin crossover refers to where a transition from the high spin (HS) state to the low spin (LS) state or vice versa occurs.Alternatives to LIESST include using thermal changes and pressure to induce spin crossover.The metal most commonly exhibiting spin crossover is iron, with the first known example, an iron(III) tris(dithiocarbamato) complex, reported by Cambi  et al.