Kohn-Sham potential with discontinuity for band gap materials
Kohn-Sham potential with discontinuity for band gap materials
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DOI：
10.1103/physrevb.82.115106
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发表时间：
2010-09-07
影响因子：
3.7
通讯作者：
Rantala, T. T.
中科院分区：
文献类型：
--
作者：
Kuisma, M.;Ojanen, J.;Rantala, T. T.
我们从 (GLLB) Gritsenko 等人的近似开始，对具有整数粒子数处的不连续性的 Kohn-Sham 势进行建模。 [物理。 Rev. A 51, 1944 (1995)]。我们评估 Kohn-Sham 能隙和不连续性以获得准粒子能隙。这使我们能够将 Kohn-Sham 间隙与通过精确的基于多体扰动理论的优化势方法获得的间隙进行比较。此外，还将所得的准粒子带隙与实验带隙进行了比较。在 GLLB 模型势中，使用广义梯度近似 (GGA) 能量密度对交换相关空穴进行建模，并使用公分母近似和基于均匀电子气的假设来评估空穴与密度变化的响应。在我们的修改中，我们选择 PBEsol 势作为 GGA 来模拟交换孔并添加一致的相关势。该方法在 GPAW 代码中实现，允许高效并行化研究大型系统。 Kohn-Sham 和准粒子带隙与半导体和其他带隙材料的公平协议是通过与 GGA 一样快的计算势获得的。
We model a Kohn-Sham potential with the discontinuity at integer particle numbers starting from the approximation by (GLLB) Gritsenko et al. [Phys. Rev. A 51, 1944 (1995)]. We evaluate the Kohn-Sham gap and the discontinuity to obtain the quasiparticle gap. This allows us to compare the Kohn-Sham gaps to those obtained by accurate many-body perturbation-theory-based optimized potential methods. In addition, the resulting quasiparticle band gap is compared to experimental gaps. In the GLLB model potential, the exchange-correlation hole is modeled using a generalized gradient approximation (GGA) energy density and the response of the hole-to-density variations is evaluated by using the common-denominator approximation and homogeneous electron-gas-based assumptions. In our modification, we have chosen the PBEsol potential as the GGA to model the exchange hole and add a consistent correlation potential. The method is implemented in the GPAW code, which allows efficient parallelization to study large systems. A fair agreement for Kohn-Sham and the quasiparticle band gaps with semiconductors and other band gap materials is obtained with a potential which is as fast as GGA to calculate.