论文标题
将固态计算扩展到超远程长度尺度
Extending solid-state calculations to ultra long-range length scales
论文作者
论文摘要
我们提出了一种方法，该方法使固态密度功能理论计算能够应用于几乎无限尺寸的系统。物理效应的计算达到微米长度尺度，但仍取决于电子结构的显微镜细节。我们的方法基于Bloch状态的概括，该概括涉及在每个$ {\ bf k} $ - 点附近的相互空间中较细的网格上的额外总和。我们表明，这允许调制晶格周期溶液顶部任意长度的密度和磁化。基于此，我们得出了一组超远程Kohn-Sham方程。我们通过含有近3500个原子的任意外部电势的样本计算来证明我们的方法。我们还通过比较BCC CR的旋转密度波与从随机磁化密度开始的直接超级电池计算来确认该方法的准确性。此外，正确再现了$γ$ -FE的自旋螺旋状态，并通过锯齿电位的密度筛选在20个硅的20个单位细胞上的密度。
We present a method which enables solid-state density functional theory calculations to be applied to systems of almost unlimited size. Computations of physical effects up to the micron length scale but which nevertheless depend on the microscopic details of the electronic structure, are made possible. Our approach is based on a generalization of the Bloch state which involves an additional sum over a finer grid in reciprocal space around each ${\bf k}$-point. We show that this allows for modulations in the density and magnetization of arbitrary length on top of a lattice-periodic solution. Based on this, we derive a set of ultra long-range Kohn-Sham equations. We demonstrate our method with a sample calculation of bulk LiF subjected to an arbitrary external potential containing nearly 3500 atoms. We also confirm the accuracy of the method by comparing the spin density wave state of bcc Cr against a direct supercell calculation starting from a random magnetization density. Furthermore, the spin spiral state of $γ$-Fe is correctly reproduced and the screening by the density of a saw-tooth potential over 20 unit cells of silicon is verified.
