In our study, we obtained free energy values of 62.75 to 5.24 kJ/mol within the 200 -1000 • C temperature range. Recent experiments on CWAs have also been carried out under similar temperatures, including vapor phase decomposition of DMMP (a sarin surrogate) at 500 -800 K, 58 sarin decomposition on TiO 2 nanoparticles at 1000 K, and decomposition of CWAs at 2000 K. Collectively, all of these experiments showed that the temperature ranges studied in this work can also be achieved under operational conditions, and DIMP would decompose on the γ-Al 2 O 3 surface. Due to the structural similarity between DIMP and sarin, our calculations provide additional insight into decomposition mechanisms of both these molecules and elucidate atomic details of sarin decomposition on candidate metal-oxide surfaces. As a final remark, this study serves as a convincing demonstration of the use of DFT-based molecular dynamics simulations for investigating the interactions of CWAs with existing metal-oxides, which can be used to guide experimental efforts on these hazardous compounds.