金-金成键：稳定19电子三元相LnAuSb（Ln = La-Nd和Sm）的关键
Gold-Gold Bonding: The Key to Stabilizing the 19-Electron Ternary Phases LnAuSb (Ln = La-Nd and Sm) as New Dirac Semimetals
摘要：
本文报道了一个新的三元111六方晶系LnAuSb（Ln = La-Nd，Sm）化合物，它的价电子数为19，比已知的LnAuZ化合物多出一个电子。第19个电子由层间的Au-Au键合容纳;这种Au-Au相互作用驱动相以YPtAs型结构结晶，而不是更常见的LiGaGe型。这是至关重要的，因为YPtAs结构类型具有形成狄拉克半金属所必需的能带交叉。能带结构、态密度和晶体轨道计算证实了这一点，这导致了在满电子态和空电子态之间几乎完全的带隙和稳定的化合物;因此，我们可以给出LnAuZ（Ln = Ge、As、Sn、Sb、Pb、Bi）相族的结构稳定性相图。这些计算还表明LaAuSb在费米能级以下有一个体狄拉克锥。这里报道的YPtAs型LnAuSb家族是以非常规方式应用于刚性封闭壳系统的金化学的独特性的一个例子。
英文摘要：
We report a new family of ternary 111 hexagonal LnAuSb (Ln = La-Nd, Sm) compounds that, with a 19 valence electron count, has one extra electron compared to all other known LnAuZ compound. The "19th" electron is accommodated by Au-Au bonding between the layers; this Au-Au interaction drives the phases to crystallize in the YPtAs-type structure rather than the more common LiGaGe-type. This is critical, as the YPtAs structure type has the symmetry-allowed band crossing necessary for the formation of Dirac semimetals. Band structure, density of stats, and crystal orbital calculations confirm this picture, which results in a nearly complete band gap between full and empty electronic states and stable compounds; we can thus present a structural stability phase diagram for the LnAuZ (Ln = Ge, As, Sn, Sb, Pb, Bi) family of phases. Those calculations also show that LaAuSb has a bulk Dirac cone below the Fermi level. The YPtAs-type LnAuSb family reported here is an example of the uniqueness of gold chemistry applied to a rigidly closed shell system in an unconventional way.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
