I am working with Macromodel, and have the problem that it generates structures in which the approach between two non-bonded hydrogens can be as little as 1.76 Angstroms, and the energy of such interactions is reported to be relatively low. I have used both the Amber force field and the MM2 force field. I don't understand how such a close interaction can have such a low energy. Can anyone please offer me an explanation? Kate Sunter.