Hartree-Fock dispersion probe of the equilibrium structures of small microclusters of benzene and naphthalene: Comparison with second-order Moeller-Plesset geometries

The equilibrium structures of small microclusters of benzene and naphthalen e were computed by a simple Hartree-Fock dispersion (HFD) model, in which a self-consistent field calculation is supplemented by an empirical dispersi on term. The minimum energy conformers so obtained with the 6-31G basis set are essentially identical to those obtained from a second-order Weller-Ple sset calculation with the same basis set. The trends in relative stabilitie s are also in general accord with those from the correlated ab initio calcu lation. These results demonstrate the utility of the HFD models in the conf ormational search of aromatic clusters.