The negative sign of this descriptor in the model indicates that electron-withdrawing substituents lead to a lower decomposition temperature. The R 1 -N 3 σ* occupancy descriptor is based on NBO analysis. As per the model equation, tetrazoles with a larger σ* occupancy have a lower decomposition temperature. The R 1 -N 3 σ* occupancy is controlled by the electronegativity of the substituent on nitrogen N 3 (H < C < N < O) and the tetrazole substitution pattern (1,5 < 2,5); the parameter correlates with the NBO charge on N 3 with a correlation coefficient of -0.78, demonstrating its relationship to the electronic properties of the ring substituent. Lastly, the max R B1 descriptor is a Sterimol parameter that quantifies the maximal B1 distance of either of the two ring substituents. This statistical model is consistent with the main decomposition pathway proposed in literature, which features a rate-limiting cleavage of the N 2 -N 3 bond followed by nitrogen extrusion from the ring-opened intermediate (Figure and 4B). Electron-demanding substituents at the R 1 and R 2 positions stabilize the ensuing formal negative charge on the C 4 -N 5 motif and a sterically hindered R1 substituent favors the rupture of the ring near N 3 .