Stochastic GW Calculations for Molecules.
Stochastic GW Calculations for Molecules.
复制标题
分子的随机引力场计算。
DOI：
10.1021/acs.jctc.7b00770
复制
发表时间：
2016
影响因子：
5.5
通讯作者：
R. Baer
中科院分区：
文献类型：
--
作者：
V. Vlček;E. Rabani;D. Neuhauser;R. Baer
准粒子（QP）激发对于理解和预测分子、纳米结构和扩展系统中的电荷转移和输运极其重要。由于Kohn-Sham（KS）公式中的密度泛函理论（DFT）不能提供可靠的QP能量，因此多体微扰技术（如GW近似）是必不可少的。GW实现的主要实际缺点是随着系统大小的高计算缩放，禁止其在具有数十个电子或更多电子的扩展的开放边界系统中使用。最近，提出了GW（sGW）的随机公式化（Phys. Rev. Lett. 2014，113，076402），其具有接近线性缩放的复杂性，针对一系列硅纳米晶体达到超过3000个电子的系统进行了说明。这一进展为在非常大的系统上进行多体计算提供了一条途径，而这在以前的方法中是不可能的。虽然之前我们已经展示了sGW的温和缩放，但其准确性并未得到广泛证明。因此，我们表明，这种新的sGW方法是非常准确的，通过计算一组足够小的分子的电离能，与其他GW代码的比较仍然是可能的。使用一组10个这样的分子，我们证明sGW提供了可靠的垂直电离能，与基准确定性GW结果（J. Chem. Theory Comput，2015，11，5665）非常一致，平均（绝对）偏差为0.05和0.09 eV。为了完整性，我们还提供了一个详细的审查sGW理论和数值实现。
Quasiparticle (QP) excitations are extremely important for understanding and predicting charge transfer and transport in molecules, nanostructures, and extended systems. Since density functional theory (DFT) within the Kohn-Sham (KS) formulation does not provide reliable QP energies, many-body perturbation techniques such as the GW approximation are essential. The main practical drawback of GW implementations is the high computational scaling with system size, prohibiting its use in extended, open boundary systems with many dozens of electrons or more. Recently, a stochastic formulation of GW (sGW) was presented (Phys. Rev. Lett. 2014, 113, 076402) with a near-linear-scaling complexity, illustrated for a series of silicon nanocrystals reaching systems of more than 3000 electrons. This advance provides a route for many-body calculations on very large systems that were impossible with previous approaches. While earlier we have shown the gentle scaling of sGW, its accuracy was not extensively demonstrated. Therefore, we show that this new sGW approach is very accurate by calculating the ionization energies of a group of sufficiently small molecules where a comparison to other GW codes is still possible. Using a set of 10 such molecules, we demonstrate that sGW provides reliable vertical ionization energies in close agreement with benchmark deterministic GW results (J. Chem. Theory Comput, 2015, 11, 5665), with mean (absolute) deviation of 0.05 and 0.09 eV. For completeness, we also provide a detailed review of the sGW theory and numerical implementation.
影响因子：
5.5
作者：
Kaplan, F.;Harding, M. E.;van Setten, M. J.
通讯作者：
van Setten, M. J.
DOI：
10.1002/wcms.1162
发表时间：
2014-03-01
影响因子：
11.4
作者：
Furche, Filipp;Ahlrichs, Reinhart;Weigend, Florian
通讯作者：
Weigend, Florian