Baroni Stefano, Moroni Saverio
Scuola Internazionale Superiore di Studi Avanzati SISSA and INFM DEMOCRITOS National Simulation Center, Via Beirut 2-4, 34014 Trieste, Italy.
Chemphyschem. 2005 Sep 5;6(9):1884-8. doi: 10.1002/cphc.200400657.
We introduce a new criterion, based on multipole dynamical correlations calculated within reptation quantum Monte Carlo, to discriminate between a melting versus freezing behavior in quantum clusters. This criterion is applied to small clusters of para-hydrogen molecules (both pristine and doped with a CO chromophore), for cluster sizes of around twelve molecules. This is a magic size at which para-hydrogen clusters display an icosahedral structure and a large stability. Despite the similar geometric structure of CO@(pH2)12 and (pH2)13, the first system has a rigid, crystalline, behavior; the second behaves more like a superfluid (or, possibly, a supersolid).
我们引入了一种基于在蛇行量子蒙特卡罗方法中计算的多极动力学关联的新判据，以区分量子团簇中的熔化与凝固行为。该判据应用于约十二个分子大小的对氢分子小团簇（包括纯净的和掺杂有一氧化碳发色团的）。这是一个神奇的尺寸，在此尺寸下对氢团簇呈现二十面体结构且具有很大的稳定性。尽管CO@(pH2)12和(pH2)13具有相似的几何结构，但第一个体系表现出刚性的晶体行为；第二个体系的行为更像是超流体（或者可能是超固体）。
