SPECTRA EFFECTS OF ULTRAFAST BARRIER CROSSING IN A 2-WELL POTENTIAL

MD simulations for a triatomic molecule, in Ar solution, where the cen tral atom moves in a double well potential were performed. The IR spec tra of the molecules gave clear evidence of the effect of increasing b arrier to the reaction: at low barrier height the signals of the two i somers are merged together and then separate increasingly as the barri er height is increased. The spectra could be fitted by Bloch lineshape s but the parameters obtained in this way were not sufficiently well d efined to be of value, Barriers estimated from the temperature depende nce of the lifetimes agreed well with those obtained from the bare pot ential indicating effective shielding of the reaction coordinate from the solvent.