ReacSpace: A Novel Methodology for Large-Scale Reaction and Species Recognition in Energetic Materials

Investigating micro-scale phenomena during shock initiation or thermal decomposition in energetic materials (EMs) holds significant importance for elucidating fundamental initiation mechanisms. This study presents methodological advancements to address current limitations in molecular simulations of large-scale EMs systems through the development of ReacSpace, a novel reaction tracking and species identification approach. The ReacSpace methodology was systematically developed, incorporating four key components: (1) bond change detection, (2) species identification, (3) reaction extraction, and (4) noise filtration. To evaluate the method's applicability for large-scale EMs simulations, comprehensive analyses were performed examining both the thermal decomposition and the shock response of α-hexahydro-1,3,5-trinitro-1,3,5-triazine (α-RDX) and ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (ε-CL-20). Compared with existing reaction analysis tools (VARxMD, ChemTraYzer, and ReacNetGenerator), the ReacSpace method demonstrates two significant advantages: (i) simultaneous multi-parameter analysis capability for monitoring chemical bond changes, reaction pathways, and species evolution dynamics and (ii) superior computational efficiency and generalizability when processing large-scale molecular dynamics simulations of EMs. The ReacSpace methodology is designed to offer enhanced analytical capabilities for elucidating complex reaction mechanisms of energetic materials at the molecular level.