Semi-Empirical Lattice Energy Calculations of Crystalline Biphenyl

Abstract

Abstract Semi-empirical lattice energy calculations based on the atom-atom potential method have been used to test several models for crystalline biphenyl. Structures considered include planar molecules in space group P21/a, nonplanar molecules disordered about an inversion center in the same group, and an ordered structure in Pa. The failure of these models to produce satisfactory (2–3%) agreement between observed and calculated cell constants suggests either the presence of a complicated disorder or of a delicate balance between intra- and intermolecular energy terms which is not adequately represented in the calculations.