Abstract The design and synthesis of new 3D carbon allotropes, especially metallic carbon allotropes, have become a focus of study among scientists. In this work, a series of 3D carbon allotropes using the self-assembling C8 skeleton of pentalene as a building block are constructed and named the superpentalene-n family. Based on first-principle calculations, their mechanical and electronic properties are evaluated. These carbon allotropes are energetically more favorable than many other previously reported allotropes, such as synthesized supercubane and T-carbon. The calculated elastic constants and simulated phonon spectra suggest that these new carbon allotropes are dynamically and mechanically stable. These new carbon allotropes exhibit high hardness, with hardness values of 38.20–65.75 GPa, and a bulk modulus of 305–366 GPa. Electronic band and band decomposed charge density calculations indicate that superpentalene-I, superpentalene-II and superpentalene-III are metallic and have one-dimensional conducting channels, whereas superpentalene-IV is a semiconductor. These findings suggest a new strategy for designing new carbon allotropes with an alkene carbon skeleton as a building block.

中文翻译：

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包含戊烯骨架的金属和半导体碳同素异形体

摘要 新型3D碳同素异形体，尤其是金属碳同素异形体的设计与合成已成为科学家们研究的热点。在这项工作中，使用戊烯的自组装 C8 骨架作为构建块构建了一系列 3D 碳同素异形体，并将其命名为 superpentalene-n 家族。基于第一性原理计算，评估了它们的机械和电子性能。这些碳同素异形体在能量上比许多其他先前报道的同素异形体更有利，例如合成的超立方烷和 T-碳。计算的弹性常数和模拟的声子光谱表明这些新的碳同素异形体在动态和机械上都是稳定的。这些新型碳同素异形体具有高硬度，硬度值为 38.20-65.75 GPa，体积模量为 305-366 GPa。电子能带和能带分解电荷密度计算表明超戊烯-I​​、超戊烯-I​​I 和超戊烯-I​​II 是金属的并且具有一维导电通道，而超戊烯-I​​V 是半导体。这些发现提出了一种设计新碳同素异形体的新策略，该碳同素异形体以烯烃碳骨架作为构建单元。