论文标题
蜂窝状晶格的热机械特性来自内部座状电势：石墨烯和六边形硼酸盐的情况
Thermomechanical properties of honeycomb lattices from internal-coordinates potentials: the case of graphene and hexagonal boron nitride
论文作者
论文摘要
低维材料中的晶格动力学，尤其是弯曲声模式的二次行为在其热力学特性中起着基本作用。对这些的第一原理评估可能非常苛刻，并且可能会受到破坏翻译或旋转不变性的数值噪声的影响。为了克服这些挑战，我们研究了Gartstein的内部坐标潜力，并在第一原理的石墨烯中调整了其13个参数。我们表明，所产生的电势不仅可以很好地再现石墨烯的声子分散，而且还可以很好地再现任何直径和手性的碳纳米管。立方术语的添加还允许重现主要的非谐声项，从而很好地估计了晶格导热率。最后，这种潜在形式也适用于硝酸硼，只要它安装在原子间力常数的短距离（分析）部分，并随后通过远程介电贡献增强。这种考虑强调了基于短材料描述符的电势如何适合第一原理相互作用的短距离部分，并以相同的第一原则计算参数为参数的远程分析介电模型互补。
Lattice dynamics in low-dimensional materials and, in particular, the quadratic behaviour of the flexural acoustic modes play a fundamental role in their thermomechanical properties. A first-principles evaluation of these can be very demanding, and can be affected by numerical noise that breaks translational or rotational invariance. In order to overcome these challenges, we study the Gartstein internal-coordinate potential and tune its 13 parameters on the first-principles interatomic force constants for graphene. We show that the resulting potential not only reproduces very well the phonon dispersions of graphene, but also those of carbon nanotubes of any diameter and chirality. The addition of a cubic term allows also to reproduce the dominant anharmonic terms, leading to a very good estimate of the lattice thermal conductivity. Finally, this potential form works very well also for boron nitride, provided it is fitted on the short-range (analytical) part of the interatomic force constants, and augmented thereafter with the long-range dielectric contribution. This consideration underscores how potentials based on short-ranged descriptors should be fit, in polar materials, to the short-range part of the first-principles interactions, and complemented by long-range analytical dielectric models parametrized on the same first-principles calculations.
