Practical GW scheme for electronic structure of 3d-transition-metal monoxide anions: ScO-, TiO-, CuO-, and ZnO-
Practical GW scheme for electronic structure of 3d-transition-metal monoxide anions: ScO-, TiO-, CuO-, and ZnO-
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DOI：
10.1063/1.5118671
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发表时间：
2019-10-07
影响因子：
4.4
通讯作者：
Ogut, Serdar
中科院分区：
文献类型：
--
作者：
Byun, Young-Moo;Ogut, Serdar
GW近似的多体微扰理论是一个可靠的工具，用于描述带电电子激发，它已成功地应用到广泛的扩展系统的几十年使用平面波的基础。然而，GW近似已经被用于测试有限系统的有限集合的有限谱特性（例如，闭合壳层SP分子的前沿轨道能量）仅使用局部轨道基础计算了大约十年。在这里，我们计算的准粒子光谱的封闭和开放的壳层分子阴离子与部分和完全填充的3D壳（浅和深3D状态，分别），ScO-，TiO-，CuO-，和ZnO-，使用不同层次的GW理论，并将它们与实验进行比较，以评估性能的GW近似的小分子的电子结构包含3D过渡金属。我们发现，G-唯一的本征值自洽GW方案与W固定到PBE水平（G（n）W（0）@PBE），这给了固体的精度和效率之间的最佳折衷，也给出了良好的结果，为本地化（d）和离域（sp）状态的3d-过渡金属氧化物分子。G（n）W（0）@PBE在预测这些系统中的电子激发方面的成功可能是由于PBE对库仑相互作用的过度屏蔽和忽略顶点校正的欠屏蔽之间的偶然抵消效应。连同不存在自洽场收敛误差（例如，开壳层系统中的自旋污染）和GW多解问题，G（n）W（0）@PBE方案给出了预测复杂真实的系统（例如，分子-固体和SP-D混合体系）。
The GW approximation to many-body perturbation theory is a reliable tool for describing charged electronic excitations, and it has been successfully applied to a wide range of extended systems for several decades using a plane-wave basis. However, the GW approximation has been used to test limited spectral properties of a limited set of finite systems (e.g., frontier orbital energies of closed-shell sp molecules) only for about a decade using a local-orbital basis. Here, we calculate the quasiparticle spectra of closed- and open-shell molecular anions with partially and completely filled 3d shells (shallow and deep 3d states, respectively), ScO-, TiO-, CuO-, and ZnO-, using various levels of GW theory, and compare them to experiments to evaluate the performance of the GW approximation on the electronic structure of small molecules containing 3d transition metals. We find that the G-only eigenvalue self-consistent GW scheme with W fixed to the PBE level (G(n)W(0)@PBE), which gives the best compromise between accuracy and efficiency for solids, also gives good results for both localized (d) and delocalized (sp) states of 3d-transition-metal oxide molecules. The success of G(n)W(0)@PBE in predicting electronic excitations in these systems reasonably well is likely due to the fortuitous cancellation effect between the overscreening of the Coulomb interaction by PBE and the underscreening by the neglect of vertex corrections. Together with the absence of the self-consistent field convergence error (e.g., spin contamination in open-shell systems) and the GW multisolution issue, the G(n)W(0)@PBE scheme gives the possibility to predict the electronic structure of complex real systems (e.g., molecule-solid and sp-d hybrid systems) accurately and efficiently.