Key Laboratory for the Physics and Chemistry of Nanodevices, Department of Electronics, Peking University, Beijing 100871, People's Republic of China.
J Chem Phys. 2012 Oct 21;137(15):154110. doi: 10.1063/1.4758986.
The model GW method [F. Gygi and A. Baldereschi, Phys. Rev. Lett. 62, 2160 (1989)] is an efficient simplification to the standard GW approximation which uses model dielectric function to describe the long range Coulomb interactions in semiconductors. In this work, the model GW method is used to calculate the quasiparticle band structures of MnO, FeO, CoO, and NiO. All four late transition metal monoxides are predicted to be insulators. The band gaps, magnetic moments, and quasiparticle spectra are in good agreement with the experiments, except for the satellite structures which are missing in the density of states because the model GW self-energy is static. The high accuracy of model GW is due to the usage of the accurate dielectric constants in the construction of the model dielectric functions which ensures the correct asymptotic behavior of the long range Coulomb interactions. Besides, we find that the transition metal 4s states are irrelevant to the formation of the band gaps, which supports the local approaches and the experimental interpretations of the band gaps by photoemission and electron energy loss spectroscopy, while contradicts the recent calculations by hybrid functionals, exact exchange, and one shot GW approximations.
GW 模型方法[F. Gygi 和 A. Baldereschi，Phys. Rev. Lett. 62, 2160 (1989)]是标准 GW 近似的一种有效简化方法，它使用模型介电函数来描述半导体中的长程库仑相互作用。在这项工作中，我们使用 GW 模型方法来计算 MnO、FeO、CoO 和 NiO 的准粒子能带结构。所有四个晚期过渡金属单氧化物都被预测为绝缘体。能带隙、磁矩和准粒子谱与实验结果非常吻合，除了由于 GW 自能是静态的，缺少态密度中的卫星结构。GW 模型的高精度是由于在构建模型介电函数时使用了精确的介电常数，这确保了长程库仑相互作用的正确渐近行为。此外，我们发现过渡金属 4s 态与能带隙的形成无关，这支持了局部方法以及光电子能谱和电子能量损失谱对能带隙的实验解释，而与最近的杂化泛函、精确交换和单次 GW 近似的计算结果相矛盾。
