Dear Colleagues; Is anyone familiar with the abbreviations "Uss" and "Upp" as they might apply to physical or quantum chemistry? They have units of eV, and may refer to something relating to spectroscopy, but as of this writing I haven't been able to find any useful definitions or descriptions of "Uss" and "Upp". Thanks in advance to all responders. Sincerely, (Dr.) S. Shapiro ZH, CH toukie &$at$& zui.unizh.ch