Structural prediction of stabilized atomically thin tin layers

Abstract

The family of group IV two-dimensional materials shows a rich variety of structural, electronic and topological properties. Only graphene is stable in the honeycomb structure, while buckling and dumbbell configurations stabilize silicene and germanene. Here we investigate from first principles the lowest-energy atomic arrangements of atomically-thin tin layers. Our calculations are performed with a very efficient method for global structural prediction, combined with constrains that enforce the desired onedimensional confinement and include the effect of strain due to the substrate. We discover a series of new structures that span a large range of atomic densities and are considerably more stable than hexagonal single-or double-layer stanene, as well as dumbbell structures. The ground state, a metallic double layer with a square lattice that lies 295 meV/atom below honeycomb stanene and only 149 meV/atom above bulk α-tin, is akin to the atomic arrangement of a layer of romarchite tin oxide. Due to its enhanced stability with respect to honeycomb stanene, we propose that this structure can be easily synthesized on appropriate lattice-matched metallic substrates.

Direct insight into the structure-property relation of interfaces from constrained crystal structure prediction

“…Our algorithm is based on the minima-hopping method 53 , 54 (MHM) for global crystal structure prediction, that we modified to direct the search away from the global minimum. In the same spirit, recent developments have allowed to use the MHM for structural prediction of surfaces 55 , low-density structures 56 and two-dimensional materials 57 – 59 . To enforce the search of GB geometries with the lowest surface energies, we introduce appropriate geometrical constraints for bulk-like regions.…”

Prediction and Characterization of Graphitic Structures at Diamond Grain Boundaries

“…In this approach, the adiabatic potential energy surface is explored by iteratively performing consecutive short molecular dynamics steps to escape from local minima, followed by local geometry relaxations that take into account both atomic and cell variables. The predictive power of this approach was already demonstrated in a wide variety of systems, ranging from bulk crystals to low-density structures, crystals with defects, ,, quasi two-dimensional materials, − and more. In particular, combining the MHM with adequate constraints, we have studied recently the geometrical reconstruction of internal interfaces in silicon and revealed the relation between recurrent bonding patterns and electronic properties at grain boundaries …”

Xenes as an Emerging 2D Monoelemental Family: Fundamental Electrochemistry and Energy Applications

“…[78,79] Except borophene, the sp 3 hybridization of 2D Xenes beyond graphene becomes progressively more and more favored than sp 2 -like planar configurations because they are affected by the electron outside the atomic layer and the radius of the atom (Figure 2d). [80] Therefore, they prefer to produce a dynamically stable buckled hexa gonal motif. [81][82][83] The buckling parameter (δ) represents the vertical distance between the two adjacent atomic layers of Xenes.…”