Mass Frontier generates fragmentation and rearrangement mechanisms along with electron shift reactions (resonance reactions). Since these reactions may, even for relatively small structures, cause a huge number of by-products, by default the resonance reactions are not depicted. To keep the reaction network clear and simple, the program performs a reduction of reaction complexity, by not displaying resonance reactions. Thus, elementary reaction steps that include resonance reactions are merged into a single step. An inexperienced mass spectrometrist might have problems in understanding such reduced mechanisms because several reaction steps are merged. If such a problem with unclear elementary reaction steps should arise, you can compel the system to display all resonance reactions by clicking the Yes radio button in the Display Resonance Reactions group box in the Resonance tab in the Reaction Restrictions dialog window.