Ab Initio Computational Study on Fe2NiP Schreibersite: Bulk and Surface Characterization

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