Turning point surfaces and their enclosed volumes for rotating Lennard-Jones rare-gas trimers ArxNe3-x, x=0-3

An earlier study (Lohr, L. L., 1997, Molec. Phys., 91, 1097) of classical t urning point surfaces of homonuclear rare-gas clusters Ar-3 and Ar-4 has be en extended to include the clusters Ne-3, ArNe2 and Ar2Ne, with emphasis on the two mixed trimers. A new procedure, applied here both to homonuclear a nd heteronuclear clusters, is the calculation by Monte Carlo integrations o f the hypervolumes enclosed by the classical turning point surfaces as func tions of the total energy and the rotational angular momentum. These hyperv olumes provide an informative characterization of the potential energy surf aces of the clusters. For a given vibrational energy it is found that the h ypervolumes decrease as Ne atoms are replaced by Ar atoms, reflecting the m ore steeply rising pair potentials for Ar-Ne and Ar-Ar interactions compare d with Ne-Ne interactions. A new result is the observation that the classic ally allowed configuration space for rotating rare-gas trimers is disconnec ted for certain ranges of total energy and rotational angular momentum; wit hin these ranges, classical trajectories which conserve rotational angular momentum are confined either to the neighbourhood of triangular structures or to that of linear structures.