A survey of the potential energy surface for the (benzene)13 cluster

Abstract

We report on a survey of the potential energy surface for the 13-molecule benzene cluster, (C₆H₆)₁₃, bound by an atom–atom intermolecular potential developed from first principles. The potential, which has an anisotropic repulsion term, is found to support distinct pairs of structures of C₃, C_i, and S₆ symmetry as low-lying minima, including a C₃ global minimum. The organisation of the low-lying region of the potential energy surface suggests that one of the S₆ structures is likely to act as a kinetic trap, hindering efficient relaxation to the global minimum, in agreement with the hypothesis that two isomers coexist in this system, suggested by spectroscopic experiments.