Real-space pseudopotential method for first principles calculations of general periodic and partially periodic systems
Real-space pseudopotential method for first principles calculations of general periodic and partially periodic systems
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DOI：
10.1103/physrevb.78.075109
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发表时间：
2008-08
影响因子：
3.7
通讯作者：
A. Natan;Ayelet Benjamini;D. Naveh;L. Kronik;M. L. Tiago;S. Beckman;J. Chelikowsky
中科院分区：
文献类型：
--
作者：
A. Natan;Ayelet Benjamini;D. Naveh;L. Kronik;M. L. Tiago;S. Beckman;J. Chelikowsky
本文提出了一种计算一般全周期或部分周期系统电子结构的实空间方法。该方法是基于Kohn-Sham方程的自洽解，使用第一原理赝势，在一个统一的三维非笛卡尔网格。它的功效来自一个新的广义高阶有限差分方法，避免了混合导数项的数值计算，并导致在一个简单而准确的有限差分算子的介绍。我们的方法被进一步扩展到仅沿沿着某些方向（例如，表面），通过建立正确的静电边界条件，并通过适当考虑离子-电子和离子-离子相互作用。我们的方法享有的主要优势，实空间网格技术比传统的平面波表示密度泛函计算，即，改进的缩放和更容易实现的并行计算机上，以及固有的免疫力虚假的相互作用所带来的人工周期性。我们在完全周期性的情况下在体相GaAs和Na上以及在部分周期性的情况下在单层Si吸附的极性硝基苯分子上证明了它的能力。
We present a real-space method for electronic-structure calculations of systems with general full or partial periodicity. The method is based on the self-consistent solution of the Kohn-Sham equations, using first principles pseudopotentials, on a uniform three-dimensional non-Cartesian grid. Its efficacy derives from the introduction of a new generalized high-order finite-difference method that avoids the numerical evaluation of mixed derivative terms and results in a simple yet accurate finite difference operator. Our method is further extended to systems where periodicity is enforced only along some directions (e.g., surfaces), by setting up the correct electrostatic boundary conditions and by properly accounting for the ion-electron and ion-ion interactions. Our method enjoys the main advantages of real-space grid techniques over traditional plane-wave representations for density functional calculations, namely, improved scaling and easier implementation on parallel computers, as well as inherent immunity to spurious interactions brought about by artificial periodicity. We demonstrate its capabilities on bulk GaAs and Na for the fully periodic case and on a monolayer of Si-adsorbed polar nitrobenzene molecules for the partially periodic case.