“…In order to avoid or at least correct this overestimation, intimately related with the classical nature of the QCT calculations, and so that theory/experiment comparisons are performed on the same footing, we introduce here some QCT constraints so that classical trajectories can be analysed in a quantum spirit. 2,56,57 Obviously, these constraints are artificial, not based on sound theoretical arguments, and so in the absence of QM calculations they represent a first approximation to the problem. Experimentally 10 little rotational excitation was observed for the SiH 3 and HF products, about 5–7% of the available energy, which represents ∼2–3 kcal mol −1 as rotational energy.…”