2005/01/08 by Ching-Ming Wei, Wei, Ching-Ming, Ching Cheng +3
Physics and Astronomy · #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.cond-mat/0501166
4 pages, 2 figures, 1 table
arxiv created 2005/01/08 · arxiv updated 2009/12/01
We propose a structural path for the icosahedra <-> fcc transition in clusters and demonstrate the transition in Pb13 by ab initio molecular-dynamics simulation. The proposed path can be described by using only two variables. The energy surface on this two-dimensional space for Pb13 was calculated and a barrierless fcc-to-ico energy path was found. The atomic displacements of the proposed structural transition for ico and fcc Pb13 were identified as one of the vibrational eigenmodes of the clusters with a soft mode for fcc Pb13. These agree with the energy curvatures around the two structures, i.e. the ico Pb13 is at the bottom of a valley on the energy surface while the fcc Pb13 is at a saddle point. The barriers of this transition for larger clusters of Pbn (n=55, 147 and 309) were also calculated, by ab initio elastic-band method, and found being smaller than the room-temperature thermal energy.