The general from of the molecular orbital energy level diagram is show in Fig. 3.33. the actual location of the orbitals (particularly the relative positions of the A set and the E set), can be found only by detailed cpmputation or by identifying the orbitals reponsible for the photoelectron spectrum. We have indicated the probable assignment of the 11 eV and 16 eV peaks, which fixes the locations of two of the occupied orbitals. the third occupied orbital is out of range of the 21 eV radiation used obtain the spectrum.