Simulations of tensile bond rupture in single alkane molecules using reactive interatomic potentials

Molecular simulations were performed to study the energetics and geometries of bond rupture in single alkane molecules using three reactive hydrocarbon potentials: (1) modified embedded-atom method (MEAM) for saturated hydrocarbons, (2) ReaxFF, and (3) second-generation REBO. The total energy/force versus strain, strain at fracture, and strain energy release were compared for a homologous series of normal alkanes (ethane to undecane) with generalization to polyethylene. The CC bond distances and CCC bond angles were quantified, and a fragment analysis was performed. Overall, the MEAM and ReaxFF potentials are in reasonable agreement with first-principles data with MEAM matching DFT-calculated lowest energy fragments.