2D planar penta-MN₂ (M = Pd, Pt) sheets identified through structure search

Abstract

Planar penta-MN2 sheets are energetically more stable than pyrite MN2, and penta-PtN2 has higher carrier mobility than phosphorene.

Two-dimensional Weyl points and nodal lines in pentagonal materials and their optical response

“…(i) There are planar and non-planar structures, which provide a means to study the effects of buckling in the electronic properties. For example, SG #127 and #55 can describe planar (atomically thin) structures [42], but they can also correspond to non-planar pentagonal structures with eight-coordinated atoms where an eight-fold WP is used to describe the site symmetry, such as in [43].…”

Toward obtaining 2D and 3D and 1D PtPN with pentagonal pattern

“…5. Different from single-layer PtN 2 and PtP 2 showing both ionic and covalent bonding characteristics, [11][12][13][14] the bonding type in single-layer PtPN is dominantly ionic and ionic bond (e.g., in BN) is often associated with large band gaps due to the large charge transfer between cations and anions.…”

“…Because only 15 types of pentagons can tessellate an infinite plane and pentagons possess intrinsic anisotropy, 10 2D materials consisting of a pattern of pentagons represent an important addition to the large family of 2D materials whose structures are dominated by patterns of other shapes especially hexagons. As two most promising examples, single-layer PtP 2 and PtN 2 [11][12][13][14] have been predicted to exhibit a unique planar, pentagonal structure and attractive electronic structures such as direct band gaps calculated at the level of hybrid density functional theory-note that the band gaps at the level of Perdew-Burke-Ernzerhof (PBE) functional theory are negligibly small. 12,15 But the stability of the bulk counterparts of these two single-layer pentagonal materials and their formation energies are likely to prohibit successful synthesis or exfoliation.…”

Two-dimensional Weyl points and nodal lines in pentagonal materials and their optical response

“…(i) There are planar and non-planar structures, which provide a means to study the effects of buckling in the electronic properties. For example, SG #127 and #55 can describe planar (atomically thin) structures, 43 but they can also correspond to non-planar pentagonal structures with eight-coordinated atoms where an eight-fold WP is used to describe the site symmetry, such as in ref. 44.…”