We introduce the stabilized geometric space to describe common geometries shared by the individual molecules, binary complexes, and the ternary complex, indicated by superscript "s" (middle row of Figure ). ∆G s geo,X is the geometric free-energy cost bringing molecule X from the free space to the stabilized geometric space. ∆G s solv,X and ∆G s X,gas are the solvation free energy and the gas-phase cooperative free energy of molecule X in the stabilized geometric space, respectively. Note that ∆G φ in Eq. ( ) does not distinguish between A, B, and L, and is invariant under molecular permutation.