Water Interaction with Fe2NiP Schreibersite (110) Surface: a Quantum Mechanical Atomistic Perspective

Phosphorus is an element of primary importance for all living creatures, being present in many biological activities in the form of phosphate (PO43-). However, there are still open questions about the origin of this specific element and on the transformation which allowed it to be incorporated in biological systems. The most probable source of prebiotic phosphorus is the intense meteoritic bombardment during the Archean era, few million years after the solar system formation, which brought tons of iron-phosphide materials (schreibersite) on the early Earth crust. It was recently demonstrated that by simple wetting/corrosion processes from this material various oxygenated phosphorus compounds are produced. In the present work, the wetting process of schreibersite (Fe2NiP) was studied by computer simulations using density functional theory, with the PBE functional supplemented with dispersive interactions through a posteriori empirical correction. To start disentangling the complexity of the system, only the most stable (110) surface of Fe2NiP was used simulating different water coverages, from which structures, water binding energies and vibrational spectra have been predicted. The computed (ana-)harmonic infrared spectra have been compared with the experimental ones, thus confirming the validity of the adopted methodology and models.