8 papers
Novel high-pressure silicon allotrope with quartz topology from first principles
Samir F. Matar, Vladimir L. Solozhenko
A novel silicon allotrope, qtz Si, with quartz topology is proposed and investigated alongside four known allotropes (dia Si-I, lon Si-IV, bsn Si-II, and gsi Si-III) using first-pr…
Novel high symmetry super-hard C48 and C32 allotropes with ana and ukc original topologies: Crystal chemistry and DFT investigations
Samir F Matar
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 engin…
Original mechanism of transformation from soft metallic (sp2/sp3) C12 to ultra-dense and ultra-hard (sp3) semi-conducting C12: Crystal chemistry and DFT characterizations
Samir F Matar
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 H…
Original Ultra-hard Orthorhombic Carbon allotropes C8 with lonsdaleite-type lon topology: Crystallographic and DFT investigations
Samir F Matar
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…
From layered 2D carbon to 3D tetrahedral original allotropes C12 and C18 with physical properties related to diamond: Crystal chemistry and DFT investigations
Samir F. Matar
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 o…
DFT investigation of novel cubic carbon allotrope, yne-C
Samir F Matar
Novel cubic allotrope yne-C with sp/sp carbon hybridizations is devised based on crystal chemistry and computations of the ground structure and the energy-dependent…
Superhard lon C5 and derived carbon nitrides: C4N and C2N2. Crystal chemistry and first principles DFT studies
Samir F Matar
Super-hard C5 with lon topology (lon: Lonsdaleite hexagonal diamond) and characterized by the presence of sp3 and sp2 -like carbon sites is devised from crystal chemistry and used…
Evolution from quartz (qtz) to diamond (dia) carbon allotropes: Crystal engineering and DFT investigations
Samir F. Matar
Based on crystal engineering and density functional theory DFT calculations a transformational pathway is proposed from qtz (quartz-based) topology characterized by distorted tetra…