A non-Dyson third-order approximation scheme for the electron propagator
A non-Dyson third-order approximation scheme for the electron propagator
复制标题
电子传播器的非戴森三阶近似方案
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
G. Stelter
中科院分区：
文献类型：
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作者：
J. Schirmer;A. Trofimov;G. Stelter
提出了一种计算原子和分子电离势和电子亲合势的有效三阶传播子方法。该发展是基于代数图解构造（ADC），表示电子传播子G（ω）的图解微扰级数的特定重新表述。与先前的近似方案不同，依赖于戴森方程和自能部分的近似，这里的ADC过程分别直接应用于电子传播子的（N <$1）电子部分G−（ω）和G+（ω）。这导致了电离能（（N−1）-电子部分）和电子亲合能（（N+1）-电子部分）的解耦久期方程。在与戴森型的方法相比，有一个显着减少的长期矩阵的维数反对由一个小的额外费用，在计算一些二阶和三阶贡献的长期矩阵元素。非Dyson ADC（3）方法与耦合系数的关系。
An efficient third-order propagator method to compute ionization potentials and electron affinities of atoms and molecules is presented. The development is based on the algebraic diagrammatic construction (ADC) representing a specific reformulation of the diagrammatic perturbation series of the electron propagator G(ω). In contrast with previous approximation schemes, relying on the Dyson equation and approximations for the self-energy part, the ADC procedure here is applied directly to the (N∓1)-electron parts G−(ω) and G+(ω), respectively, of the electron propagator. This leads to decoupled secular equations for the ionization energies ((N−1)-electron part) and electron affinities ((N+1)-electron part), respectively. In comparison with the Dyson-type approach, there is a substantial reduction of the secular matrix dimension opposed by a small additional expense in computing some second- and third-order contributions to the secular matrix elements. The relationship of the non-Dyson ADC(3) method to coupl...