Hydrogen bond
Hydrogen bonds can vary in strength from weak (1–2 kJ mol) to strong (161.5 kJ mol in the ion ). Typical enthalpies in vapor include:
Kaonic hydrogen
Unlike in the hydrogen atom, where the binding between electron and proton is dominated by the electromagnetic interaction, kaons and protons interact also to a large extent by the strong interaction.
In kaonic hydrogen this strong contribution was found to be repulsive, shifting the ground state energy by 283 ± 36 (statistical) ± 6 (systematic) eV, thus making the system unstable with a resonance width of 541 ± 89 (stat) ± 22 (syst) eV (decay into Λπ and Σπ).