Studies in hydrogen bonding: Association within small clusters of water,methanol, and ammonia molecules using Jorgensen's intermolecular pair potentials

The geometries of the dimer, trimer, and tetramer hydrogen-bonded clusters of water, methanol, and ammonia molecules have been derived using previously published intermolecular pair potentials containing constants optimized from ab initio calculations. The lowest energy forms for the dimers of all three types of molecules have an open structure, while the trimers and tetramers have cyclic structures. The results are compared with those previously described using another empirical potential, EPEN .