“…Moreover, the spectra reported in the literature for the possible fragments do not match the observed losses. In particular the vibrational spectrum of vinyl, whose formation was suggested by Zhou and White [14], was measured for adsorption on Ni(0 0 1) [21] and exhibits a doublet at 114 and 95 meV, corresponding to the wagging modes of the CH 2 and CH groups, respectively, with twist (145 meV), rock (160 meV) and scissor (176 meV) modes of comparable intensity, contrary to our experimental result. Moreover the CH stretch of vinyl has two components at 365 and 386 meV, which are not observed in our case.…”