We present the results of atomistic simulations using derived interatomic potentials for the pyrite-structured metal chalcogenides FeS(2), PtSb(2) and PtAs(2). Structural and elastic constants were calculated and compared with experimental measurements. Surface energies of low-index surfaces were calculated and closely reflected the measured stabilities of these compounds. Equivalent surfaces on the pyrite and marcasite structures of FeS(2) explained the experimentally observed intergrowths of the two phases.

We discuss the nature of the defects involved in the incorporation of hydrogen in oxides and silicates. We describe how computational techniques may be used to investige the structures and energies of hydrogen containing defects in these materials.