Dresden 2011 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
O: Fachverband Oberflächenphysik
O 101: Particles and clusters II
O 101.3: Talk
Friday, March 18, 2011, 11:45–12:00, WIL C107
Stabilization mechanism for cage-like Si16M+ clusters: From global structure optimization to understanding — •Dennis Palagin1, Matthias Gramzow2, and Karsten Reuter1,2 — 1Technische Universität München — 2Fritz-Haber-Institut der Max-Planck-Gesellschaft, Berlin
Doping with endohedral metal atoms appears as a remarkable avenue to tailor the intrinsic properties of silicon clusters, as well as to stabilize cage-like geometries as suitable building blocks for novel engineered materials. A prevalent concept to rationalize this stabilization is that injection of metal electrons into the Si electron gas leads to electronic shell closure. A prominent example is Si16V+, which with 68 valence electrons corresponds to a closed-shell configuration. Intriguingly, Si16Ti+ and Si16Cr+ with 67 and 69 electrons, respectively, are equally believed to stabilize in cage-like geometries [1]. Aiming to further clarify the stabilization mechanism we first use density-functional theory based basin-hopping to ascertain that the cage-like geometry indeed represents the ground-state structure for all three dopant atoms. From this basis we proceed to a detailed analysis of the obtained charge distributions to identify the nature of the bond and the stabilization mechanism in this dopant sequence. [1] J.T. Lau et al., Phys. Rev. A 79, 053201 (2009).