Interpretation
Consider in the context of particle insertion (ghost ? real)
High-S system is ghost, Low-S is real
u is the difference in energy Ureal - Ughost
pH is the distribution of energies (virtual energy changes) experienced by molecule acting as a ghost (insertion energy)
- many overlaps, so energy will tend to be large
pL is the distribution of energies experienced by a molecule interacting with the others (deletion energy)
- no overlap, favorable interactions, so energy will be small