15min:
ASYMMETRIC TOP ROTORS IN SUPERFLUID PARA -HYDROGEN NANO-CLUSTERS.

TAO ZENG, Department of Chemistry, University of Waterloo, Waterloo, ON, Canada, N2L 3G1; HUI LI, Institute of Theoretical Chemistry, State Key Laboratory of Theoretical and Computational Chemistry, Jilin University, 2519 Jiefang Road, Changchun 130023, People's Republic of China; AND PIERRE-NICHOLAS ROY, Department of Chemistry, University of Waterloo, Waterloo, ON, Canada, N2L 3G1.

We present the first simulation study of bosonic clusters doped with an asymmetric top molecule. A variation of the path-integral Monte Carlo method is developed to study a para -water ( p H2O) impurity in para -hydrogen ( p H2) clusters. The growth pattern of the doped clusters is similar in nature to that of the pure clusters. The p H2O molecule appears to rotate freely in the cluster due to its large rotational constants and the lack of adiabatic following. The presence of p H2O substantially quenches the superfluid response of p H2 with respect to the space fixed frame. We also study the behaviour of a sulphur dioxide (32S16O2) dopant in the p H2 clusters. For such a heavy rotor, the adiabatic following of the p H2 molecules is established and the superfluid renormalization of the rotational constants is observed. The rotational structure of the SO2- p (H2)N clusters' ro-vibrational spectra is predicted. The connection between the superfluid response respect to the external boundary rotation and the dopant rotation is discussed.