title: The Stone-Wales transformation: from fullerenes to graphite, from radiation damage to heat capacity.
abstract: The Stone-Wales (SW) transformation, or carbon-bond rotation, has been fundamental to understanding fullerene growth and stability, and ab initio calculations show it to be a high-energy process. The nature and topology of the fullerene energy landscape shows how the Ih-C60 must be the final product, if SW transformations are fast enough, and various mechanisms for their catalysis have been proposed. We review SW transformations in fullerenes and then discuss the analogous transformation in graphite, where they form the Dienes defect, originally posited to be a transition state in the direct exchange of a bonded atom pair. On the basis of density functional theory calculations in the local density approximation, we propose that non-equilibrium concentrations of the Dienes defect arising from displacing radiation are rapidly healed by point defects and that equilibrium concentrations of Dienes defects are responsible for the divergent ultra-high-temperature heat capacity of graphite.This article is part of the themed issue 'Fullerenes: past, present and future, celebrating the 30th anniversary of Buckminster Fullerene'.
authors: Department of Chemistry, University of Sussex, Falmer, Brighton BN1 9QJ, UK Department of Chemistry, University of Surrey, Guildford GU2 7XH, UK malcolm.heggie@gmail.com.
authors: M I
authors: 0000-0002-6332-6652
authors: MI
authors: Heggie
authors: Department of Chemistry, University of Sussex, Falmer, Brighton BN1 9QJ, UK.
authors: G L
authors: GL
authors: Haffenden
authors: Department of Chemistry, University of Surrey, Guildford GU2 7XH, UK.
authors: C D
authors: 0000-0003-0509-925X
authors: CD
authors: Latham
authors: Department of Chemistry, University of Surrey, Guildford GU2 7XH, UK.
authors: T
authors: 0000-0002-2062-8693
authors: T
authors: Trevethan
keywords: Dienes defect; Stone–Wales; fullerenes; graphite; heat capacity; local density approximation