Abstract By means of the isolobality concept between a hydrogen atom and the radical dianion [B6H5• ]2− derived from an extraction of a hydrogen atom in the dianion [B6H6]2−, forming part of the K2(B6H6) structure, we rationalize the 3D boron skeleton architecture in the solids CaB6 and KB6. The above statement is supported by electronic structure computations based on the Electron Localisation Function (ELF) in the dianion [B6H6]2− and radical anion [B6H5•]2−. Valence-Bond (VB) theory is also used in the study of the B–B sigma bond connecting the octahedra in the CaB6 structure, with the model dimer [(H5B5)B–B(B5H5)]4−. Quantum-chemical geometry optimizations of clusters extracted from the CaB6 solid structure show the analogies between molecular chemistry and solid-state chemistry: In the same way as benzene is the building block of graphene and graphite, the anion [B6H6]2− is the building block of CaB6 provided every hydrogen atom in [B6H6]2− is connected to a further [(B•)6]2− octahedron in the three directions of the 3D space, and every void at the Ca positions is embedded with two electrons.

中文翻译：

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固体 CaB6 和分子二价阴离子 B6H6(2-) 之间的电子和结构关系：一项计算研究

摘要 通过氢原子和自由基二价阴离子 [B6H5• ]2- 之间的等叶性概念，该概念源自对二价阴离子 [B6H6]2- 中氢原子的提取，形成 K2(B6H6) 结构的一部分，我们合理化固体 CaB6 和 KB6 中的 3D 硼骨架结构。上述陈述得到基于二价阴离子 [B6H6]2- 和自由基阴离子 [B6H5•]2- 中的电子定位函数 (ELF) 的电子结构计算的支持。价键 (VB) 理论也用于研究连接 CaB6 结构中八面体的 B-B σ 键，模型二聚体 [(H5B5)B-B(B5H5)]4-。从 CaB6 固体结构中提取的簇的量子化学几何优化显示了分子化学和固态化学之间的类比：