Improved
long-range reactive bond-order potential for carbon. I. Construction
Jan H. Los, Luca M. Ghiringhelli, Evert Jan Meijer, and A. Fasolino,
Abstract
We present LCBOPII, an improvement of the long-range carbon bond-order
potential (LCBOP) by Los and Fasolino [Phys. Rev. B 68, 024107 (2003)].
LCBOPII contains a coordination dependent medium range term for bond
distances between 1.7 and 4 Å, meant to reproduce the
dissociation energy curves for single, double, and triple bonds and
improve the reactive properties as well as the description of the
liquid and of low coordinated phases. Other features of LCBOPII are a
coordination dependent angular correlation, a correction for
antibonding states, and a conjugation dependent torsional interaction
based on ab initio calculations of the torsional barriers for a set of
molecular configurations. We present results for the geometry and
energetics of the graphite-to-diamond transformation and of the vacancy
in diamond and graphite as well as the prediction of the energy barrier
of the 5-77-5 defect in graphite and graphene for which ab initio
results are available only for unsuitably small samples. In the
accompanying paper (Ghiringhelli et al., Phys. Rev. B 72, 214103 (2005)
we use LCBOPII to evaluate several properties, including the equation
of state, of liquid carbon.