Mixing ReaxFF parameters for transition metal oxides using force-matching method.

We present the development of the method for the refitting the ReaxFF parameters for a system consisting of the mixed transition metal oxides. We have tested several methods allowing to calculate the differences between the vectors of the forces acting on atoms obtained from the reference DFT simulation and the parameters-dependent ReaxFF. We conclude that the footrule method yields the best parameters among the investigated options.

Helping Thy Neighbor: How Cobalt Doping Alters the Electrocatalytic Properties of Hematite.

We present analysis of the indirect role of Co doping on the electrocatalytic activity of α-FeO. Upon substitution of one of the Fe atoms in the hematite surface, we observed a promoting effect of the substitution, upon which the overpotential required for the water-splitting reaction decreased in all substitution sites investigated. The cobalt site itself, however, does not exhibit the improved properties with respect to the undoped hematite.

Rehybridization-induced charge density oscillations in the long-range corrugated silicene.

Freestanding silicene is a one-atom-thick two-dimensional material composed of Si atoms arranged in a honeycomb lattice that is related to graphene. Its low-buckled atomic structure facilitates the functionalization of silicene. We report on an alternative method of functionalization which utilizes one-dimensional long-range periodic structural deformation of silicene, and leads to rehybridization-induced sublattice-polarized charge density oscillations.

Electrical and mechanical controlling of the kinetic and magnetic properties of hydrogen atoms on free-standing silicene.

Effects of strain, charge doping and external electric field on kinetic and magnetic properties of hydrogen atoms on a free-standing silicene layer are investigated by first-principles density functional theory. It was found that the charge doping and strain are the most effective ways of changing the hydrogen-silicene binding energy, but they can only raise its value. The perpendicular external electric field can also lower it albeit in a narrower range.

Dirac fermions in silicene on Pb(111) surface.

First-principles density functional theory calculations of silicene deposited on a Pb(111) surface are reported. Several possible silicene superstructures, exhibiting different scanning tunnelling microscopy topography images have been found. All the structures feature low binding energy and very small charge transfer, thus interact weakly with the substrate.