NEW HYPOTHETICAL CARBON ALLOTROPES OF REMARKABLE STABILITY ESTIMATED BY MODIFIED NEGLECT OF DIATOMIC OVERLAP SOLID-STATE SELF-CONSISTENT FIELD COMPUTATIONS

A new family of yet unknown carbon modifications has been proposed. The underlying building principle consists of connecting triptycyl moieties by benzene rings in two dimensions so that 2D hexagonal nets (with regular or irregular hexagons) emerge and then connecting identical nets by simple bonds. The resulting infinite structures can be described as a mixture of sp3 and sp2 carbons and are of hexagonal nature. Some of the allotropes are crystalline, but most of these 3D solids possess only a translational symmetry in one dimension. An attempt to estimate their stability by modified neglect of diatomic overlap solid-state calculations revealed that the stability of these allotropes is comparable to that of diamond.