Analysis of the Configurations of a Crystal Surface. Pyrope (Mg3Al2Si3O12) as a Case Study

This paper presents a working methodology to determine all the possible surface configurations of a hkl crystal face. As a case study, we have applied our strategy to individuate the surface configurations of the {100}, {110}, and {112} forms of pyrope (Mg3Al2Si3O12). To identify the most stable surface termination, we have performed an accurate ab initio study of the surface structures and energies at 0 K of the pyrope {100} configurations, by using the hybrid Hartree–Fock/density functional B3LYP Hamiltonian and a localized all-electron Gaussian-type basis set. Even if we are mainly interested in obtaining informations about the habit and genesis of natural garnets included in diamond (and pyrope is the main component of garnets trapped in diamonds), our results could be extremely useful to any researcher involved in the study of the surfaces of whatever crystalline phase.