Influence of solution stoichiometry on the thermodynamic stability of prenucleation FeS clusters

The significance of iron sulphide (FeS) formation extends to "origin of life" theories, industrial applications, and unwanted scale formation. However, the initial stages of FeS nucleation, particularly the impact of solution composition, remain unclear. Often, the iron and sulphide components' stoichiometry in solution differs from that in formed particles. This study uses ab initio methods to computationally examine aqueous FeS prenucleation clusters with excess Fe(II) or S(-II). The results suggest that clusters with additional S(-II) are more likely to form, implying faster nucleation of FeS particles in S(-II)-rich environments compared to Fe(II)-rich ones.