In an effort to extend the reach of current ab initio calculations to simulations requiring millions
of configurations for complex systems such as heterostructures, we have parameterized the thirdgeneration
Charge Optimized Many-Body (COMB3) potential using solely ab initio total energies,
forces, and stress tensors as input. The quality and the predictive power of the new forcefield are
assessed by computing properties including the cohesive energy and density of SiO2 polymorphs,
surface energies of alpha-quartz, and phonon densities of states of crystalline and amorphous phases
of SiO2. Comparison with data from experiments, ab initio calculations, and molecular dynamics
simulations using published forcefields including BKS (van Beest, Kramer, and van Santen), ReaxFF,
and COMB2 demonstrates an overall improvement of the new parameterization. The computed
temperature dependence of the thermal conductivity of crystalline alpha-quartz and the Kapitza
resistance of the interface between crystalline Si(001) and amorphous silica is in excellent agreement
with experiment, setting the stage for simulations of complex nanoscale heterostructures. C 2016 AIP
Publishing LLC.