Implementation and Validation of Fully Relativistic GW Calculations: Spin-Orbit Coupling in Molecules, Nanocrystals, and Solids
Implementation and Validation of Fully Relativistic GW Calculations: Spin-Orbit Coupling in Molecules, Nanocrystals, and Solids
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DOI：
10.1021/acs.jctc.6b00114
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发表时间：
2016-08-01
影响因子：
5.5
通讯作者：
Galli, Giulia
中科院分区：
文献类型：
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作者：
Scherpelz, Peter;Govoni, Marco;Galli, Giulia
我们提出了一个G（0）W（0）计算的实现，包括自旋轨道耦合（SOC），使调查的大型系统，成千上万的电子，我们讨论了分子，固体和纳米晶体的结果。使用一组新开发的重元素分子（称为GW-SOC 81），我们发现，当基于混合密度泛函计算时，完全相对论（FR）和标量相对论（SR）G（0）W（0）计算的垂直电离势与实验相比都有很好的性能，误差小于1.9%。我们表明，虽然SR计算有较高的随机误差，FR计算系统地低估VIP的0.1至0.2 eV。我们进一步验证了SOC效应可以很好地近似在FR密度泛函水平，然后添加到SR G（0）W（0）的结果，为广泛的一类系统。我们还讨论了G（0）W（0）准粒子方程的不同求根算法的使用以及在G（0）W（0）计算的赝势的价分配中包括d电子的显著影响。最后，我们提出了我们的数据的统计分析，强调明确的改善，可能会发生的机会，由于有限的样本数量分离的重要性。我们建议这里使用的统计分析将是有用的，在评估的准确性，各种各样的电子结构的方法。
We present an implementation of G(0)W(0) calculations including spin-orbit coupling (SOC) enabling investigations of large systems, with thousands of electrons, and we discuss results for molecules, solids, and nanocrystals. Using a newly developed set of molecules with heavy elements (called GW-SOC81), we find that, when based upon hybrid density functional calculations, fully relativistic (FR) and scalar-relativistic (SR) G(0)W(0) calculations of vertical ionization potentials both yield excellent performance compared to experiment, with errors below 1.9%. We demonstrate that while SR calculations have higher random errors, FR calculations systematically underestimate the VIP by 0.1 to 0.2 eV. We further verify that SOC effects may be well approximated at the FR density functional level and then added to SR G(0)W(0) results for a broad class of systems. We also address the use of different root finding algorithms for the G(0)W(0) quasiparticle equation and the significant influence of including d electrons in the valence partition of the pseudopotential for G(0)W(0) calculations. Finally, we present statistical analyses of our data, highlighting the importance of separating definitive improvements from those that may occur by chance due to a limited number of samples. We suggest the statistical analyses used here will be useful in the assessment of the accuracy of a large variety of electronic structure methods.