Core-Level Binding Energies from GW: An Efficient Full-Frequency Approach within a Localized Basis
Core-Level Binding Energies from GW: An Efficient Full-Frequency Approach within a Localized Basis
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DOI：
10.1021/acs.jctc.8b00458
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发表时间：
2018-09-01
影响因子：
5.5
通讯作者：
Rinke, Patrick
中科院分区：
文献类型：
--
作者：
Golze, Dorothea;Wilhelm, Jan;Rinke, Patrick
GW方法通常用于预测分子和固体中的带电价激发。然而，在计算x射线光电子能谱（XPS）测量的核心激发时，最有效的GW算法所采用的数值技术就失效了。我们在实轴上提出了一种全频率方法，使用局部基础来处理GW中的核心水平。该方案基于轮廓变形技术，可以精确有效地计算自能量，而核心状态具有复杂的极点结构。通过与全解析式GW算法的比较，验证了本文方法的准确性。此外，我们还报道了一组小分子和大分子多环烃的核能级结合能及其与实验的偏差。用我们的GW方法计算的磁芯能级与实验参考偏差小于0.5 eV。为了进行比较，我们还报道了基于密度泛函理论（DFT）的方法计算核能级结合能的方法，如流行的delta自洽场（delta SCF）方法。我们的实现针对大规模并行执行进行了优化，可以计算多达100个原子的系统。
The GW method is routinely used to predict charged valence excitations in molecules and solids. However, the numerical techniques employed in the most efficient GW algorithms break down when computing core excitations as measured by X-ray photoelectron spectroscopy (XPS). We present a full-frequency approach on the real axis using a localized basis to enable the treatment of core levels in GW. Our scheme is based on the contour deformation technique and allows for a precise and efficient calculation of the self-energy, which has a complicated pole structure for core states. The accuracy of our method is validated by comparing to a fully analytic GW algorithm. Furthermore, we report the obtained core-level binding energies and their deviations from experiment for a set of small molecules and large polycyclic hydrocarbons. The core-level excitations computed with our GW approach deviate by less than 0.5 eV from the experimental reference. For comparison, we also report core-level binding energies calculated by density functional theory (DFT)-based approaches such as the popular delta self-consistent field (Delta SCF) method. Our implementation is optimized for massively parallel execution, enabling the computation of systems up to 100 atoms.