A semi-empirical parameter predicting the sensitivity of energetic materials from external pressure

Measuring the ability of a material to absorb energy from an external stimulus is crucial for understanding the sensitivity mechanism of energetic materials (EMs). Based on this, a semi-empirical parameter, M, is proposed to measure the material's ability to absorb energy from an external stimulus, which is closely related to zero-point energy and volume. In this work, taking the external pressures (P) of 0.1 and 1.0 GPa as examples, we calculate the value of M for 16 EMs, and discuss the relationship between M and the impact sensitivity of EMs (E₅₀). Considering the indispensable influence of molecular structure on the impact sensitivity of EMs, 16 EMs are divided into Groups A and B according to their structure whether contains a benzene ring. We find that the correlation between M₀ and E₅₀ when P is 0.1 GPa is less than that when P is 1.0 GPa. Therefore, the parameter M₀ has been modified by adding the initial zero-point energy, and the modified parameter is referred to as M_∗. The correlation between M_∗ and E₅₀ is further improved compared with M₀. In particular, for Group B, the correlation between M_∗ and E₅₀ is good, where R² is 0.95 and PCCs is 0.97 when P is 1.0 GPa, and R² is 0.87 and PCCs is 0.92 when P is 0.1 GPa.