So often I see total energies of transition states corrected for zero-point vibrational energy which always confuses me. Zero point energy is the lowest energy that a ground state minimum energy configuration can have at 0K in a vacuum. Transition states are indeed not minima, can never be isolated, have one imaginary mode of vibration, etc.
So why do people constantly factor in zero-point vibrational energy to the total energy for a transition state? Obviously this is done to have 'comparable' minima and TS energetics (if you are applying ZPE to the minima) but is this even physical? If zero-point correcting the TS, should the zero-point energy of the imaginary mode be included in the summation or excluded (or should both quantities be provided)?