![Sample our Mathematics & Statistics journals, sign in here to start your FREE access for 14 days]({"type":"image" , "src" : "/sda/5943/TOC-Subject-Sample-2021-Mathematics-Statistics.jpg"})
Abstract
We are extending the use of the method of static simulation of ionic lattices to modelling phosphates and condensed phosphates, the mineral components of many biominerals whose structure, crystallinity and reactivity can be influenced by substitutions and other defects. Parameters for the interatomic potentials of some phosphates and pyrophosphates have been determined and we present our results for the modelling of α-magnesium pyrophosphate, a representative compound of moderate complexity. The approach has been to treat the compound as an ionic solid with Mg2+ as the cation and P2O7 4 as a predominately covalent anion which is, however, ionically bound to the metal. Good agreement was found between the calculated and experimental structures for this ionic model using formal or residual charges, a Born-Mayer term for non-bonded repulsive interactions, whose parameters were calculated using the electron gas technique, a van der Waals dispersion term and three body terms to account for the directionality of bonding in the phosphate groups in the tetrahedra.