EXTENDED ELECTRON DISTRIBUTIONS APPLIED TO THE MOLECULAR MECHANICS OFSOME INTERMOLECULAR INTERACTIONS .2. ORGANIC-COMPLEXES

Extended electron distributions (XEDs) have been used to simulate the formation of complexes by intermolecular interaction via: (i) aromatic stacking; and (ii) hydrogen bonding. The results qualitatively reprod uce experimental observations. In contrast, atom-centred partial charg es fail to reproduce highly hydrogen-bonded systems, but make little d ifference in cases where interactions are driven largely by van der Wa als forces. The dielectric constant used in the Coulombic term has bee n shown to be significant in defining the type and properties of these interactions when XEDs are employed. Some consideration has been give n to solvation and entropy effects.