OBSERVATION OF THE ISOMERIZATION STATES OF HCP BY STIMULATED-EMISSIONPUMPING SPECTROSCOPY - COMPARISON BETWEEN THEORY AND EXPERIMENT

Highly excited vibrational states of HCP (X) over tilde (1) Sigma(+) w ere investigated by stimulated emission pumping spectroscopy. Two dist inct families of vibrational states were observed in the 13400-17500 c m(-1) energy region. One of them is ''normal-mode-type'' states, well characterized by polyads involving the bending (omega(2)) and CP stret ching (omega(3)) vibrations. The other is delocalized ''isomerization states'' whose existence has been predicted by a recent theoretical st udy [J. Chem. Phys. 104, 10055 (1996)]. The present spectroscopic obse rvations agree well with the theoretical predictions. (C) 1997 America n Institute of Physics.