论文标题
评论“ Pentadiamond：SP2和SP3 C原子的五角大楼网络的硬碳同素同形”
Comment on "Pentadiamond: A Hard Carbon Allotrope of a Pentagonal Network of sp2 and sp3 C Atoms"
论文作者
论文摘要
在最近的一封信中，Fujii等。 al。 [物理。莱特牧师。 125，016001]预测了一种新的碳同素同素异形物，五角星，具有显着的机械性能：弹性模量可比或大于钻石，而负泊松的比率为$μ$ = -0.241。估计的维克（Vicker）硬度为422 GPA，$ \ sim $ 4.6倍（$ \ sim $ \ sim $ 92 GPA），这是迄今已知最难的材料。但是，五角星尚未进行调查。由此激励，我们使用了不同的方法来估计基于密度功能理论的不同近似值的五角星的弹性特性。这些测试还进行了钻石和其他已知的硬碳同素同质子的验证。通过测试，我们发现Pentadiamond的弹性常数和弹性模量在参考文献中报道。 [物理。莱特牧师。 125，016001]是不正确的，五角星应被视为非运动软碳同素同形。
In a recent Letter, Fujii et. al. [Phys. Rev. Lett. 125, 016001] predicted a new carbon allotrope, pentadiamond, with remarkable mechanical properties: elastic moduli comparable or larger than diamond, and negative Poisson's ratio $μ$ = -0.241. The estimated Vicker's hardness is 422 GPa, $\sim$4.6 times higher than in diamond($\sim$92 GPa), the hardest material known to date. Pentadiamond, however was not investigated. Motivated by this, we used different approaches to estimate the elastic properties of pentadiamond with different approximations based on Density Functional Theory. The tests were also carried out on diamond and other known hard carbon allotropes for validation. Through tests, we found that the elastic constants and elastic moduli of pentadiamond reported in Ref. [Phys. Rev. Lett. 125, 016001] are incorrect, and pentadiamond should be considered a non-auxetic soft carbon allotrope.
