New development beyond the GW approximation and its application to the electronic structure of solids

1.高田基于他自己的理论计算了电子液体的准粒子能量，该理论使人们能够在守恒近似方法的框架内通过迭代来考虑所有关于自能的费曼图。然后，他得到了与Yasuhara等人(1999)相同的结论，即从角分辨光电发射实验中预测的简单金属占据带宽的收窄实际上归因于传统的使用自由电子能量作为末态能级，相反，如果使用准粒子能量，则带宽在交换和关联的影响下有所增加。他的计算首次考虑了单对(或等离子体激元)和多对激发的不可分割的耦合。2.用同样的理论，高田还计算了整个金属密度区电子液体的动力学结构因子S(Q，ω)，发现t…更重要的是，由低ω处的单对激发引起的ω线性谱形状被粒子洞多次散射增强，而单对和多对激发之间的相消干涉在中间ω处产生了一种变黄的光谱结构。这与传统的RPA光谱形状有很大不同。3.利用Yasuhara-Takada理论(1991)，Ishihara等人对钠的能带进行了计算，发现在交换和关联的影响下，钠的占据带宽增加了不到10%。他们已经确定，钠在理想球面上的费米面变形是由赝势决定的，而不受传导电子之间的交换和关联的影响。4.Yasuhara和Higuchi借用电子液体中的长、中、短程关联知识，构造了一个与轨道相关的关联能泛函，并与轨道相关的交换能泛函一起用于能带计算。他们预测，重费米子系统可能会被解释为在费米能级附近由关联诱导的Kohn-Sham轨道的重建，在费米能级附近，通过混合传导和f电子轨道，态密度被异常增强，从而获得与轨道相关的关联能量泛函的量级。较少

1. Takada has calculated the quasiparticle energy of the electron liquid, based on his own theory that enables one to consider by iteration all Feynman diagrams for the self-energy by requiring the Pauli principle in the framework of the conserving approximation method. He has then obtained the same conclusion by Yasuhara et al (1999) that the narrowing in the occupied bandwidth of simple metals predicted from angular resolved photoemission experiments is in fact ascribed to the traditional use of the free electron energy as the final state level and on the contrary the bandwidth is somewhat increased under the influence of exchange and correlation if one uses the quasiparticle energy instead. His calculation has for the first time allowed for an inseparable coupling of one-pair (or plasmon) and multi-pair excitations. 2. Using the same theory Takada has also calculated the dynamical structure factor S(q,ω) of the electron liquid over the entire region of metallic densities and found t … More hat the ω-linear spectral shape due to one-pair excitations at low ω is enhanced by particlehole multiple scattering and the destructive interference between one and multi-pair excitations produces a flauened spectral structure at intermediate ω. These are quite different from the conventional RPA spectral shape. 3. Using the Yasuhara-Takada theory (1991) Ishihara et al have performed a band calculation of sodium and found that its occupied bandwidth is by less than 10% increased under the influence of exchange and correlation. They have ascertained that the Fermi surface distortion of sodium from the perfect sphere is determined by the pseudo-potential, not influenced by exchange and correlation between conduction electrons. 4. Yasuhara and Higuchi have constructed an orbital-dependent correlation energy functional for use in band calculations in combination with the orbital-dependent exchange energy functional, borrowing the knowledge of long-, intermediate-, and short-range correlations from the electron liquid. They have predicted that heavy fermion systems probably will be interpreted in terms of the correlation-induced reconstruction of Kohn-Sham orbitals in the vicinity of the Fermi level where the density of states is extraordiarily enhaced by mixing conduction and f-electron orbitals to gain the magnitude of that orbital-dependent correlation energy functional. Less