Structural and Electronic Properties of Ruthenium-Doped Germanium Clusters

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• 作者：Yuanyuan Jin ; Yonghong Tian ; Xiaoyu Kuang ; Cheng Lu ; José Luis Cabellos ; Sukanta Mondal ; Gabriel Merino
• 刊名：Journal of Physical Chemistry C
• 出版年：2016
• 出版时间：April 21, 2016
• 年：2016
• 卷：120
• 期：15
• 页码：8399-8404
• 全文大小：426K
• 年卷期：0
• ISSN：1932-7455

文摘

We have performed a global minimum search for the multicharged ruthenium-doped germanium clusters with the formula RuGe_n^q (n = 2–12, q = −2, – 3) using a particle swarm optimization metaheuristic coupled with density functional theory computations. Leading candidates for the lowest energy forms have been identified. Among the global minimum geometries, going from the size of n = 2 to n = 12, it is perceived that the cluster growth is directed toward the formation of an endohedral aggregate. Particularly, the half-encapsulated structures of RuGe₇^q and RuGe₈^q made the bridge between small open-shell (n = 2–6) geometries and the endohedral (n = 9–12) geometries. The endohedral constructions contain the Ru atoms at their interstitial positions. Particularly, the 10-vertex endohedral cluster RuGe₁₀^2– has an unprecedented 3-connected C_3v polyhedral geometry. The positive values of highest occupied molecular orbital energies of global minimum anions depict the electronic instability. The countercation effect is discussed to show the compensation of Coulomb repulsion among excess negative charges. RuGe₁₂^2– and RuGe₁₂^3– have S₄- and D_2d-symmetric endohedral shapes, respectively, which match with the previous experimental results. The natural population analysis charge is also examined to understand the associated charge transfers.