Efficientab initiomolecular-dynamics simulations of carbon

We evaluate an ab initio scheme for performing molecular-dynamics simulations of elemental carbon. The method involves no free parameters and has been rigorously tested in a wide range of bonding environments. For elemental covalent systems this approach has an accuracy comparable to other density-functional schemes, and is more efficient. Carbon microclusters, bulk diamond, and graphite are discussed. The vibrational spectrum of ${\mathrm{C}}_4$ is examined in detail with a Bayesian probability theoretic analysis of the vibrational modes of the molecule at a variety of kinetic temperatures.