Affiliations: Departamento de Fí sica Teórica, Universidad de Valladolid, Valladolid 47011, Spain | [x] Department of Chemistry, University of Patras, Greece | [y] Departamento de Quimica, CINVESTAV, Centro De Investigacion Y De Estudios Avanzados, Av. Instituto Politecnico Nacional, 2508, A.P. 14-740, Mexico, D.F. 07000, Mexico
Abstract: We investigate the possible influence of a global cluster rotation on the melting-like transition of Na30, Na55 and Na147, by means of orbital-free density-functional molecular dynamics simulations. The results reveal that very large angular momenta L→ are needed to significantly alter the results of simulations performed on nonrotating clusters, and therefore validate the usual L=0 approximation made in computer simulations of cluster thermal properties. However, a global rotation might have a more profound influence on the thermal properties in the limit of very small cluster sizes, when the ratio of rotational to vibrational degrees of freedom is not negligible. For those clusters which are in a highly excited rotational state, we find enhanced isomerization rates and even depressed melting points.
Keywords: Sodium clusters, melting points, ab initio molecular dynamics
