An electron impact energy-loss study of triplet states of acetylene

Abstract
Electron impact energy-loss spectra have been obtained for acetylene in the range 4 to 8 eV at various impact energies and scattering angles. At low impact energies structure attributed to two triplet states is observed as long vibrational progressions. Analysis of the structure indicated that in the ground vibrational level of each triplet state, the molecule has a trans-bent geometry, and the configurations 13Au and 13Bu are suggested. The lowest vibrational level observed for the 13Au state has an excitation energy of 4.36+or-70.007 eV.