Decomposition of energetic saltsTKX-50 and MAD-X1 (dihydroxylammonium 5,5′-bistetrazole-1,1′-diolateand dihydroxylammonium 3,3′-dinitro-5,5′-bis-1,2,4-triazole-1,1′-diol,respectively), following electronic state excitation, is investigatedboth experimentally and theoretically. The NO and N2moleculesare observed as initial decomposition products from the two materialssubsequent to UV excitation. Observed NO products are rotationallycold (<25 K) and vibrationally hot (>1500 K). The vibrationaltemperature of the NO product from TKX-50 is (2600 ± 250) K,(1100 ± 250) K hotter than that produced from MAD-X1. ObservedN2products of these two species are both rotationallycold (<30 K). Initial decomposition mechanisms for these two electronicallyexcited salts are explored at the complete active space self-consistentfield (CASSCF) level. Potential energy surface calculations at theCASSCF(8,8)/6-31G(d) level illustrate that conical intersections playan essential role in the decomposition mechanisms. Electronicallyexcited S1molecules can nonadiabatically relax to thelower electronic state through (S1/S0)CIconical intersections. Both TKX-50 and MAD-X1 have two (S1/S0)CIconical intersections between S1and S0states, related to and leading to two differentreaction paths, forming N2and NO products. N2products are released by the opening of the tetrazole or triazolerings of TKX-50 and MAD-X1. NO products are released from the amineN-oxide moiety of TKX-50, and for MAD-X1, they are produced throughnitro–nitrite isomerizations. The observed rotational energydistributions for NO and N2products are consistent withthe final structures of the respective transition states for eachmolecule on its S0potential energy surface. [ABSTRACT FROM AUTHOR]