Department of Physics, Virginia Commonwealth University, Richmond, Virginia 23284, USA.
J Chem Phys. 2012 Apr 7;136(13):134311. doi: 10.1063/1.3700086.
The electronic structure and stability of the XMg(8) clusters (X = Be, B, C, N, O, and F) are studied using first principles theoretical calculations to understand the variation in bonding in heteroatomic clusters which mix simple divalent metals with main group dopants. We examine these progressions with two competing models, the first is a distorted nearly free electron gas model and the second is a molecular orbital picture examining the orbital overlap between the dopant and the cluster. OMg(8) is found to be the most energetically stable cluster due to strong bonding of O with the Mg(8) cluster. BeMg(8) has the largest HOMO-LUMO gap due to strong hybridization between the Mg(8) and the Be dopant states that form a delocalized pool of 18 valence electrons with a closed electronic shell due to crystal field effects. Be, B, and C are best described by the nearly free electron gas model, while N, O, and F are best described through molecular orbital concepts.
使用第一性原理理论计算研究了 XMg(8) 团簇（X = Be、B、C、N、O 和 F）的电子结构和稳定性，以了解混合简单二价金属和主族掺杂剂的杂原子团簇中键合的变化。我们用两种竞争模型来研究这些进展，第一个是扭曲的近自由电子气模型，第二个是分子轨道图，研究掺杂剂和团簇之间的轨道重叠。由于 O 与 Mg(8) 团簇的强键合，OMg(8) 被发现是最稳定的团簇。由于 Mg(8) 和 Be 掺杂态之间的强烈杂化，BeMg(8) 具有最大的 HOMO-LUMO 能隙，形成一个离域的 18 价电子池，由于晶体场效应，具有封闭的电子壳层。Be、B 和 C 最好用近自由电子气模型来描述，而 N、O 和 F 最好用分子轨道概念来描述。
