https://doi.org/10.1140/epjd/e2007-00095-7
Theoretical study of molecular hydrogen clusters
Growth models and magic numbers
1
Departamento de Física Teórica, Atómica y Óptica, University of Valladolid, 47001 Valladolid, Spain
2
Donostia International Physics Center (DIPC), 20018 San Sebastián, Spain
Corresponding author: a jaalonso@fta.uva.es
Received:
24
July
2006
Revised:
20
October
2006
Published online:
24
May
2007
Hydrogen clusters are formed by packing H2 molecules. A structural characterization of (H2)N clusters up to N=35 has been carried out at zero temperature by using density functional theory. The binding between the hydrogen molecules is very weak and the cluster growth reminds that of the inert gas clusters. An icosahedron is obtained for (H2)13. For clusters larger than (H2)13 several growth models have been compared. The binding energy indicates specially stable clusters for some particular sizes. The magic numbers can be related to Raman spectroscopy experiments, where the intensity of the Raman signal serves to assign enhanced abundance to clusters with N≈13,32,55, which coincide with some of the most stable clusters obtained in the present study. In addition, comparison of theory and experiment suggests that clusters with N smaller than 27 are liquid. The photoabsorption spectra have been calculated using time-dependent density functional theory. Those spectra can be interpreted as a widening of the absorption peaks of the H2 molecule due to the various environments experienced by different molecules in the same cluster.
PACS: 30. – Atomic and molecular physics / 31. – Electronic structure of atoms and molecules: theory / 31.15.Ew – Density-functional theory
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2007
