Table I.

Electrostatic Energy (kcal/mol) for Water Hydrogen Bonded Dimers At Equilibrium Separation.

X	Mono.a	Dip.	Quad.	Oct.	Hex.	RVS
Water	−6.845	−7.074	−7.502	−7.520	−7.542	−7.546
Methanol	−7.172	−6.735	−7.238	−7.257	−7.285	−7.265
Formamide	−11.35	−11.18	−11.75	−11.78	−11.86	−11.98
Ammonia	−8.594	−9.130	−9.982	−10.06	−10.07	−10.03
Acetylaldehyde	−6.808	−6.221	−6.849	−6.879	−6.922	−7.022
Dimethyl Ether	−5.791	−6.438	−6.744	−6.828	−6.840	−6.787
rmsd	0.713	0.734	0.140	0.117	0.078

^aGaussian monopoles, dipoles, quadrupoles, octapoles, and hexadecapoles fit to the HF/6-31G* ESP are compared to the reference ab initio RVS values.