Stable structures of neutral and ionic Ge n ( n=11–19) clusters

Abstract

The lowest-energy structures of neutral and ionic Ge n ( n=11–19) clusters are obtained by using the full-potential linear-muffin-tin-orbital molecular-dynamics (FP-LMTO-MD) method based on some genetic operations. We find a number of new ground state structures, which are more stable than those reported previously. Most of the lowest energy structures for the neutral and ionic Ge n ( n=11–19) clusters are obviously different from those of the corresponding Si n clusters although the geometrical configurations of the small clusters ( n<10) are basically the same. Our results also show that all the lowest energy structures of the cationic Ge n ( n=11–19) clusters have the similar geometrical configurations to those of the corresponding neutral Ge n ( n=11–19) clusters except for n=11. However, for the anionic Ge n ( n=11–19) clusters, the conclusion is almost the reverse. In addition, for the smaller clusters with n≤13, the polyhedral structures are more favorable, while the larger clusters from n=14 prefer the stacked structures. For the negative ions, their ground state structures transit from stacked structures into compacted structures at n=18.