Communication: the description of strong correlation within self-consistent Green's function second-order perturbation theory.
Communication: the description of strong correlation within self-consistent Green's function second-order perturbation theory.
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通信：自洽格林函数二阶微扰理论中强相关性的描述。
DOI：
10.1063/1.4884951
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
D. Zgid
中科院分区：
文献类型：
--
作者：
J. Phillips;D. Zgid
我们报告了在二阶近似（GF2）内自洽格林函数多体理论的实现，以应用于分子系统。这是通过在原子轨道基础上以矩阵形式表示的戴森方程的迭代求解来完成的，其中格林函数和自能分别建立在虚频域和虚时域上，并使用快速傅里叶变换根据需要有效地转换这些量。我们将此方法应用于几个强相关性的典型示例，例如即使在平衡晶格间距下也显示高度多参考电子基态的 H32 有限晶格。在所有情况下，GF2 都对这些系统中的金属到绝缘体的转变给出了物理上有意义的描述，而无需诉诸自旋对称性破缺。我们的结果表明，自洽的格林函数多体理论提供了一种描述强相关性的可行途径，同时保持在计算上易于处理的单粒子形式主义内。
We report an implementation of self-consistent Green's function many-body theory within a second-order approximation (GF2) for application with molecular systems. This is done by iterative solution of the Dyson equation expressed in matrix form in an atomic orbital basis, where the Green's function and self-energy are built on the imaginary frequency and imaginary time domain, respectively, and fast Fourier transform is used to efficiently transform these quantities as needed. We apply this method to several archetypical examples of strong correlation, such as a H32 finite lattice that displays a highly multireference electronic ground state even at equilibrium lattice spacing. In all cases, GF2 gives a physically meaningful description of the metal to insulator transition in these systems, without resorting to spin-symmetry breaking. Our results show that self-consistent Green's function many-body theory offers a viable route to describing strong correlations while remaining within a computationally tractable single-particle formalism.