The use of atom-atom potentials in the calculation of intermolecular forces between large molecules

Abstract

The crystal structure of acenaphthylene has been calculated by assuming the intermolecular forces may be represented as a sum of pairwise interactions between atoms. The calculated structure is shown to be remarkably insensitive to the values of the parameters used in an ?exp- 6? type atom-atom potential; variation of the parameters associated with the attractive part of the exp-6 potential has less effect than variation of the repulsive parameters. It is deduced that the actual values of the parameters in the atom-atom potential have little significance and that the correct crystal structures could be predicted by any approximately correct repulsive potential.