Ab initio Bethe-Salpeter calculations of the x-ray absorption spectra of transition metals at the L-shell edges
Ab initio Bethe-Salpeter calculations of the x-ray absorption spectra of transition metals at the L-shell edges
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DOI：
10.1103/physrevb.86.195135
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发表时间：
2012-11-26
影响因子：
3.7
通讯作者：
Rehr, J. J.
中科院分区：
文献类型：
--
作者：
Vinson, J.;Rehr, J. J.
我们提出了从头计算Bethe-Salpeter方程（BSE）计算的L-2，L-3边的几个绝缘和金属化合物含有钙，钒，铁，钴，镍，铜，跨越一系列的3d电子占领。我们的方法包括扩展态和原子多重态效应的统一处理的关键成分，即，布洛赫态、自洽晶体势、基态磁性、GW自能修正、自旋轨道项以及L-2和L-3能级之间的库仑相互作用。该方法在OCEAN软件包中实现，该软件包使用平面波赝势波函数作为基础，投影仪增广波结构的过渡矩阵元素，和预解形式主义的BSE计算。结果是在近定量协议与实验，包括在边缘的精细结构和非统计L-3/L-2比观察到这些系统。近似，如依赖于时间的密度泛函理论被证明是不太准确的。
We present ab initio Bethe-Salpeter equation (BSE) calculations of the L-2,L-3 edges of several insulating and metallic compounds containing Ca, V, Fe, Co, Ni, and Cu, spanning a range of 3d-electron occupations. Our approach includes the key ingredients of a unified treatment of both extended states and atomic multiplet effects, i.e., Bloch states, self-consistent crystal potentials, ground-state magnetism, GW self-energy corrections, spin-orbit terms, and Coulomb interactions between the L-2 and L-3 levels. The method is implemented in the OCEAN package, which uses plane-wave pseudopotential wave functions as a basis, a projector-augmented-wave construction for the transition matrix elements, and a resolvent formalism for the BSE calculation. The results are in near quantitative agreement with experiment, including both fine structure at the edges and the nonstatistical L-3/L-2 ratios observed for these systems. Approximations such as time-dependent density-functional theory are shown to be less accurate.