We perform a critical test on two theoretical approaches of calculating inter-molecular interaction energies of Hbonded systems namely, super-molecular and AIM. We choose conventional H-bonds existing in dimers and complexes of H2O, HF and NH3 and notice that there are substantial differences in the values calculated by two schemes. AIM approach seems to be better to calculate hydrogen bond strengths. However, a more detailed study with diverse set of molecules is needed in order to compare the reliability of schemes.
