Dynamic non-equilibrium chemical bonding pathways under thermomechanical compression

The most urgent need in the explosion science of chemical reactions is about time-resolved non-equilibrium processes on when and how mechanical work and thermal heat are deposited into molecules to initiate reactions. Using quantum solid-state chemistry calculations, multi-resolution and multi-scale dynamic non-equilibrium simulations were recently developed for chemical reactions under compression. The non-equilibrium reaction processes are characterized by the lowest resolution in reactant and resultant conformations, the intermediate resolution in energy, enthalpy, mechanical stress, and chemical shear flows, and the highest resolution in reactive modes selected by compression. The dynamic motion of these flows is governed by a number of equations with respect to time, including the conservation of momentum and energy together with effects of mechanical endothermic bond compression, thermal heat transfer, and exothermic energy release of bond breaking related to irreversible Arrhenius kinetics with volume change and energy barriers. It provides details of dynamic non-equilibrium chemical bonding pathways from quantum to continuum scales. Simulations agreed well with experimental observations such as shock compressed graphite transformed into hexagonal diamond.