Related papers: First-principles study of lithium-doped carbon cla…
We present an ab-initio calculation of the electronic affinity of the hypothetical C-46 clathrate by studying its bare and hydrogenated (100) surfaces. We show that such a system shares with the diamond phase a small electronic affinity.…
Understanding the covalent clathrate formation is a crucial point for the design of new superhard materials with intrinsic coupling of superhardness and metallic conductivity. Silicon clathrates have the archetype structures that can serve…
Clathrates are lightweight, cage-like, fully-sp3 three dimensional (3D) structures that are experimentally-available for several host elements of the IV group. However, carbon clathrates are as yet hypothetical structures. Herein, the…
Investigations of clathrate structures have gained a new impetus with the recent discovery of room-temperature superconductivity in metal hydrides. Here we report the finding, through density functional theory calculations, of a clathrate…
The formation and presence of clathrate hydrates could influence the composition and stability of planetary ices and comets; they are at the heart of the development of numerous complex planetary models, all of which include the necessary…
The structural and electronic properties of germanium clathrates Ge$_{46}$ and K$_8$Ge$_{46}$ are studied by first principles calculations within the local density approximation. The equilibrium structures are obtained by {\em ab initio}…
We propose an atomistic model for the pressure-induced isostructural phase transition of metal-doped silicon clathrates, Ba8Si46 and K8Si46, that has been observed at 14 GPa and 23 GPa, respectively. The model explains successfully the…
Carbon at extreme conditions is the focus of intensive scientific inquiry due to its importance for applications in inertial confinement fusion experiments and for understanding the interior structure of carbon-rich exoplanets. The extreme…
Solid CS$_{2}$ is superficially similar to CO$_{2}$, with the same $Cmca$ molecular crystal structure at low pressures, which has suggested similar phases also at high pressures. We carried out an extensive first principles evolutionary…
The response to compression of the clathrate type-II structure Ge(cF136) is investigated by means of \textit{ab initio} small-cell metadynamics at different temperatures and pressures. At lower pressure $p$=2.5 GPa the metastable metallic…
Boron-based clathrate materials, typically with three-dimensional networks of B atoms, have tunable properties through substitution of guest atoms, but the tuning of B cages themselves has not yet been developed. By combining crystal…
Diamond possesses exceptional physical properties due to its remarkably strong carbon-carbon bonding, leading to significant resilience to structural transformations at very high pressures and temperatures. Despite several experimental…
The uniquely characteristic macrostructures of binary hydrogen-clathrate compounds $M$H$_\textrm{n}$ formed at high pressure, a cage of hydrogens surrounding a central-atom host, is theoretically predicted in various studies to include…
Metal-stuffed B$-$C compounds with sodalite clathrate structure have captured increasing attention due to their predicted exceptional superconductivity above liquid nitrogen temperature at ambient pressure. However, by neglecting the…
The immense interest in carbon nanomaterials continues to stimulate intense research activities aimed to realize carbon nanowires, since linear chains of carbon atoms are expected to display novel and technologically relevant optical,…
Elemental calcium (Ca), a simple metal at ambient conditions, has attracted huge interest because of its unusual high-pressure behavior in structural, electrical, and melting properties whose origin remain unsolved. Here, using a…
Inspired by the first boron-carbon (B-C) clathrate SrB$_3$C$_3$ and the ternary borohydride KB$_2$H$_8$ [Miao et al., Phys. Rev. B 104 L100504 (2021)], we have performed first-principles density functional theory calculations of the…
We report a density-functional theory study of the structural and electronic properties of Cd2V2O7 under high-pressure conditions. The calculations have been performed by using first-principle calculations with the CRYSTAL program. The…
High-temperature high-pressure superconducting hydrides are typically characterized by cage-like hydrogenic lattices filled with electropositive metal atoms. Here, density functional theory based evolutionary crystal structure searches find…
Electronic properties of silicon-based clathrates can be tuned by boron incorporation into the silicon cage network. Sodium borosilicides clathrate outstands with uncommon stoichiometry and expected metallic properties, in contrast to other…