High temperature pure carbon nanoparticle formation: validation of AIREBO and ReaxFF reactive molecular dynamics

Abstract Molecular dynamics with reactive interatomic potentials is the only computationally feasible approach for modeling at the atomistic level the formation of carbon nanoparticles from gas state. Such models require thousands of atoms and millions of time steps that is beyond the current capabilities of first principles electronic structure calculations. A continuously growing variety of available reactive interatomic potentials for carbon requires their careful validation for a particular molecular system and pressure-temperature conditions. In this work we consider a generic example process of carbon nanoparticle formation at cooling of the gas phase and compare different AIREBO and ReaxFF reactive models. Three main processes of clusterization, change of hybridization and graphitization are analysed and used for comparison of potentials. Ab initio density functional theory and parameterized density functional tight-binding calculations together with experimental data available are used for validation of the reactive models considered. We highlight the detected problems of some well-known reactive potentials and conclude with three models that can be selected as the best options for molecular dynamics simulations of pure carbon nanoparticle formation.