The modified Kamlet and Jacobs approach for rapidly predicting the equation of state and Chapman–Jouguet point of high explosives

We propose here the modified Kamlet and Jacobs equation, RoseModKJ (Reparametrization of the slope for expansion adiabats), to predict the pressure at different relative volumes across the expansion adiabat. This RoseModKJ equation provides predictions that are in good agreement with predictions from the EXPLO-5 empirical code, with experimental values, and with ReaxFF/QM-MD first principles based simulations. This study provides a robust model, RoseModKJ, to quickly derive expansion adiabats from elemental composition and packing density, without requiring an enthalpy of formation. This provides very fast predictions of the expansion adiabats, including the region near the Chapman–Jouguet (CJ) that predicts detonation velocity, pressure, and temperature, useful for developing new generations of energetic materials for propulsion and detonation applications.