Related papers: Ultra-hard hexagonal C$_{12}$ with C3 cyclopropane…
Novel ultra-hard carbon allotrope is proposed with mechanical, dynamic, and thermal properties like diamond. Based on energy criteria from computations within density functional theory DFT, tetragonal C8 stoichiometry is identified as a…
Two mechanisms of changes from 2D to 3D (D = dimensionality) involving 2D C(sp2) trigonal paving to C(sp3) tetrahedral stacking are proposed through puckering of the 2D layers on one hand and interlayer insertion of extra C on the other…
Novel high symmetry body centered carbon allotropes: cubic C48 and tetragonal C32 are proposed with respective original ana and ukc topologies. Devised from crystal structure engineering, their ground state structures and energy derived…
Original carbon allotropes C12 and C16 called superglitter and squarodiamond from relationships with literature glitter and squaroglitter respectively are shown through DFT-based geometry to be cohesive with energy dependent properties as…
Based on crystal chemistry considerations and quantum density functional theory ground state calculations, rhombohedral rh-C3 and hexagonal h-C6 carbon allotropes are proposed and energetically calculated as new stable ultra-hard phases…
A new ultra-hard rhombohedral carbon rh-C4 (or hexagonal h-C12) is reported as derived from 3R graphite through crystal chemistry construction and ground state energy within the density functional theory. An extended hexagonal…
From crystal chemistry rationale and density functional DFT calculations, novel tetragonal carbon C5 is proposed as simplest ultrahard allotrope with mixed hybrid carbon hybridizations (sp2 - sp3). Novel pentacarbon is identified as…
A structurally stable crystalline carbon allotrope is predicted by means of the first-principles calculations. This allotrope can be derived by substituting each atom in diamond with a carbon tetrahedron, and possesses the same space group…
The lon topology inherent to lonsdaleite C4 hexagonal diamond is shown to characterize three original carbon allotropes C8 in the orthorhombic system with irregular orientations of the C4 tetrahedra. The octacarbon stoichiometries were…
Superstructures of cubic and hexagonal diamonds (h- and c-diamond) comprising a family of stable diamond-like $sp^3$ hybridized novel carbon allotropes are proposed, which are referred to as U$_n$-carbon where $n \geq 2$ denotes the number…
Original carbon allotropes, orthorhombic C8, C10, C12 and C14 presenting mixed sp2 and sp3 carbon hybridizations exhibiting ethene like and propadiene like embedded units are proposed from crystal chemistry and calculations within the…
Novel extended networks of C8, Si8 and silicon carbide Si4C4 are proposed based on crystal chemistry rationale and optimized structures to ground state energies and derived physical properties within the density functional theory (DFT). The…
An original mechanism is proposed for a pressure-induced transformation of orthorhombic C12 from ground state normal pressure (NP) sp2/sp3 allotrope to ultra-dense and ultra-hard HP sp3 form. Upon volume decrease, the trigonal C=C parallel…
Based on C8, carbon 4C, with cfc topology, two hybrid carbon allotropes generated by inserting C(sp2) and C(sp1) carbon atoms into C8 diamond-like lattice were identified and labeled ene-C10 containing C(sp2) and ene-yne-C14 containing…
A novel stable carbon allotrope is predicted by using first-principles calculations. This allotrope is obtained by replacing one of the two atoms in the primitive cell of diamond with a carbon tetrahedron, thus it contains five atoms in one…
We have investigated the structural, mechanical and electronic properties of D-carbon by ab initio calculations, a new phase of crystalline sp3 carbon (pace group D2h5, Pmma-orthorhombic). Total-energy calculations demonstrate that D-carbon…
We present a comprehensive first-principles investigation of a novel carbon allotrope characterized by quasi-tetragonal atomic motifs and quasi-two-dimensional structural behavior. Structural analysis reveals an open framework composed of…
A metallic covalently bonded carbon allotrope is predicted via first principles calculations. It is composed of an $sp^3$ carbon framework that acts as a diamond anvil cell by constraining the distance between parallel cis-polyacetylene…
Two novel three-dimensional (3D) crystal structures of carbon (C) and germanium carbide (GeC2) were predicted using first-principles density-functional theory (DFT) calculations. These newly discovered 3D carbon allotrope and GeC2 are in…
A novel allotrope of carbon with $P2/m$ symmetry was identified during an \emph{ab-initio} minima-hopping structural search which we call $M10$-carbon. This structure is predicted to be more stable than graphite at pressures above 14.4 GPa…