THEORETICAL PREDICTION OF POTENTIAL ENERGY SURFACE FOR N14 CLUSTER

Abstract

In addition to four isomers of N 14 cluster previously reported, one new isomer was investigated. The decomposition and isomerization pathways of these five N 14 isomers were studied using the density functional theory (DFT) method. Relative energies were refined at the B3LYP/6-311+G(3df, 2p)//B3LYP/6-31G* level of theory. The present study shows that the decomposition barrier heights for the isomers 1, 2, and 3 are all much lower than 20 kcal/mol, which hints the fact that it may be possible to observe these three isomers only as short-lived species at room temperature. The barrier height for the cis-trans isomerization reaction of the isomers 4 and 5 is about 43.3 kcal/mol at the B3LYP/6-113+G(3df, 2p)//B3LYP/6-31G* level of theory. Unfortunately, however, the decomposition barrier height for the isomer 4 is about 17.9 kcal/mol. For the isomer 5, one barrier height corresponding to the - N 4 side chain breaking to lose the N 2 molecules is about 32.9 kcal/mol, however, the other barrier height corresponding to the - N 5 side chain breaking to lose a N 2 molecule is about 17.1 kcal/mol. From the study presented here, it seems that these five N 14 isomers are not kinetically stable enough to serve as high energy density materials (HEDMs).