Therefore, the energy available to products is ~ 28 kcal mol -1 . Taking into account this available energy and the HCN(v1,v2,v3) vibrational frequencies, one must expect a high vibrational excitation in all vibrational modes, up to four quanta in the CN stretching mode, up to two quanta in the CH stretching mode and up to thirteen quanta in the bending mode. These values correspond to pure vibrational states, but obviously any stretchingbending combination is possible, compatible with the energy, for instance, (1,4,1). This high population of the three modes simulates the experimental evidence. Figure presents a schematic representation of the available energy and pure excited vibrational states for the HCN(v1,v2,v3) product.