论文标题
C和GEC2的新稳定晶体结构预测了第一原理计算
New stable crystal structures of C and GeC2 predicted from first-principles calculations
论文作者
论文摘要
使用第一原理密度功能理论（DFT）计算预测了两个新型的三维（3D）晶体结构。这些新发现的3D碳同素和GEC2位于FMMM的太空组（空间组69）中。它们的晶体结构具有由C或GE/C原子形成的独特四方/六角形环。通过声子频谱计算，这两种结构均被证明是热力学稳定的。 c同素是一个半导体，其宽带间隙为3.65 eV，由杂交密度功能性HSE06方法预测，而GEC2是金属的。新的C同素质量的低质量密度为2.84 g/cm3。更重要的是，事实证明，它在能量上具有稳定的稳定，而粘性能量小于-7.5 eV/原子，该原子比许多其他碳同素同素型低，这意味着在实验室中制造的可能性。一旦合成的质量密度较低和宽带隙的这种碳晶体结构将在气体吸附传感器和光电设备中具有广泛的应用。
Two novel three-dimensional (3D) crystal structures of carbon (C) and germanium carbide (GeC2) were predicted using first-principles density-functional theory (DFT) calculations. These newly discovered 3D carbon allotrope and GeC2 are in the space group of Fmmm (space group number 69). Their crystal structures have unique tetragonal/hexagonal rings formed by either C or Ge/C atoms. Both structures were proven to be thermodynamically stable through the phonon spectrum calculations. The C allotrope is a semiconductor with a wide band gap of 3.65 eV predicted by the hybrid density functional HSE06 method, while GeC2 is metallic. The new C allotrope has a low mass density of 2.84 g/cm3. More importantly, it is proven to be energetically stable with cohesive energy less than -7.5 eV/atom which is lower than many other carbon allotropes implying the possibility to be fabricated in lab. Such a carbon crystal structure with a low mass density and wide band gap once synthesized would have wide applications in gas adsorption sensors and photo-electronic devices.
