, Volume 3, Issue 5, pp 743-752,
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Structure of small hydrogen nanoclusters containing ortho-molecules

Abstract

Using the quantum mechanical path integral Monte Carlo method, we simulated parahydrogen clusters (j = 0) and clusters doped with several (up to 6) orthohydrogen molecules (j = 1), with the total number of molecules ranging from 4 to 40 at temperatures of 1.5, 3, and 4.5 K. Some energy parameters (including the chemical potentials) and spatial characteristics of the clusters are found. At a temperature of 1.5 K, as the total number N of molecules in the cluster increases, the chemical potential and the rotational energy of the clusters attain local minima at the same geometrically determined values of N (the magic numbers). The ortho-molecules exhibit a larger probability (compared to the para-molecules) to reside in the central region of the cluster and a smaller probability to be located near its surface. This effect is enhanced as the number of orthohydrogen molecules in the cluster increases, the total number N of molecules grows, or the temperature is lowered.

Original Russian Text © V.M. Akimov, L.I. Kolesnikova, L.Yu. Rusin, M.B. Sevryuk, J.P. Toennies, 2009, published in Khimicheskaya Fizika, 2009, Vol. 28, No. 9, pp. 33–42.
The article was translated by the authors.