Abstract We identify by ab initio calculations a stable three-dimensional carbon allotrope that constructed by inserting benzene rings into the carbon-carbon bonds in a previously reported oC8 carbon. This new carbon phase has a 24-atom orthorhombic unit cell in C m m m ( D 2 H 19 ) symmetry and thus termed oC24. Phonon mode analysis confirms its dynamical stable. Total-energy calculations show that it is energetically stable comparable with (5,5) carbon nanotube. Detailed electronic band calculations reveal that oC24 is a topological node-line semimetal with two mirror-inversion symmetric nodal lines that go through the whole Brillouin zone in bulk and a projected surface flat band around the Fermi level. The present results establish a new type of carbon phases and offer insights into their outstanding structural and electronic properties.

中文翻译：

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正交碳oC24：一种新型拓扑节点线半金属

摘要 我们通过从头算计算确定了一个稳定的三维碳同素异形体，该同素异形体是通过将苯环插入先前报道的 oC8 碳中的碳-碳键而构建的。这种新的碳相具有 C mmm (D 2 H 19 ) 对称性的 24 原子正交晶胞，因此称为 oC24。声子模式分析证实其动态稳定。总能量计算表明，它与 (5,5) 碳纳米管相比在能量上是稳定的。详细的电子能带计算表明，oC24 是一种拓扑节点线半金属，具有两条镜像反转对称节点线，它们整体穿过整个布里渊区，并在费米能级周围有一个投影表面平坦带。目前的结果建立了一种新型的碳相，并提供了对其出色结构和电子特性的见解。