An Isotopic Substitution Test for Orbiting H Atoms in Vibrationally Highly Excited $\tilde{X} ^{1}\Sigma_{g}^{+}$ Acetylene

Author Institution: Department of Chemistry, Massachusetts Institute of Technology; Laboratoire de Spectrometrie Physique, Universite Scientifique et Medicale de Grenoble; Department of Chemistry, University of Southern California