Figure 3.

Schematic representation of the bonding interaction and the evolution of the energy of the individual diabatic structures and the global adiabatic state associated with this process for (a) [H₃N–H]⁺, (b) [H₂S–H]⁺, and (c) [H₂O–H]⁺. Note that the curve associated with Φ_ion,2 is not depicted in this figure due to the significant energy gap between this curve and those associated with Φ_ion,1 and Φ_HL, respectively. Spin-pairing stabilization energies associated with Φ_HL upon bond formation are depicted in italics in blue; resonance energies are shown in magenta. Weights of the individual structures in the adiabatic wave function at the optimal bonding distance are shown at the bottom of each panel.