Before starting the analysis of the HCN product vibrational analysis, one of the main objectives of the present paper, we present a series of previous considerations. The total energy available to the products corresponds to the sum of the collision energy, Ecoll, the 0 K enthalpy of reaction, and the C2H6 rotational energy. At 298 K the collision energy was obtained from an energy distribution (see Section 3) with the most probable values between 0.5 and 1.5 kcal mol -1 . Here, we assume an average value of ~1.0 kcal mol -1 . The C2H6 rotational energy was obtained by thermal sampling at 298 K, which adds on average 0.9 kcal mol -1 . The enthalpy of reaction at 0 K is -26.0 kcal mol -1 .