Carbon: A Suggested New Hexagonal Crystal Form

Abstract

Evidence for a new polymorphic form of carbon, similar to but distinct from chaoite, has been discovered. It is trigonal, with a₀ = 5.33 angstroms and c₀ = 12.24 angstroms. It is produced along with chaoite on the surfaces of graphitic carbons under free-vaporization conditions at low pressures, with temperatures above approximately 2550°K.