Ab-Initio Computational Study on Fe2NiP schreibersite: Bulk and Surface Characterization

Phosphorous is ubiquitous in planet Earth and plays a fundamental role in all living systems. Finding a reasonable prebiotic source of phosphorous is not trivial, as common sources where it is present nowadays are in the form of phosphate minerals, which are rather insoluble and non-reactive materials, and, accordingly, unavailable for being readily incorporated in living organisms. A possible source of phosphorous is from the exogenous meteoritic bombardment and, in particular, in iron/nickel phosphites. These materials, by simple interaction with water, produce oxygenated phosphorous compounds, which can easily react with organic molecules, thus forming C-O-P bonds. In the present work, periodic ab-initio simulations at PBE level (inclusive of dispersive interactions) have been carried out on metallic Fe₂NiP-schreibersite, as a relative abundant component of metallic meteorites, in order to characterize structural, energetics and vibrational properties of both bulk and surfaces of this material. The aim is to study the relative stability among different surfaces, to characterize both the nanocrystal morphology and the reactivity towards water molecules.