LDA+DMFT approach to multi-band correlation phenomena: Susceptibilities and structural relaxation

具有相关电子的材料的动力学平均场方法使我们对这类系统的物理性质的理解取得了重大进展。为了能够解释和预测日益复杂的材料的性质，该方法需要在几个方向上进一步发展。在这个项目中，我们将重点关注三个具体主题：(i)为了确定相关材料对外部扰动的响应，从而获得有关系统不稳定性的信息，我们将扩展计算方案，使其能够计算动力和波矢量相关的敏感性；（ii）为了便于对理论单粒子光谱密度与实验光发射光谱进行实际的定量比较，我们将扩展理论，使其包括相应算符的矩阵元素给出的适当跃迁幅度；（iii）为了更好地理解电子相关对晶格结构的影响，我们将推广动态平均场方法，在相同的基础上处理相关材料的电子和结构特性。后一个子项目预计将导致一个通用的计算方案，能够执行结构优化和计算相关材料的动态晶格性质。

The dynamical mean-field approach to materials with correlated electrons has led to significant progress in our understanding of the physical properties of such systems. To be able to explain and predict the properties of increasingly complex materials the approach needs to be further developed in several directions. In this project we will focus on three specific topics: (i) In order to determine the response of correlated materials to external perturbations and thereby obtain information about instabilities of the system, we will extend the computational scheme such that it is capable of computing dynamical and wave-vector dependent susceptibilities; (ii) to facilitate a realistic quantitative comparison of theoretical single-particle spectral densities with experimental photoemission spectra we will extend the theory to include the proper transition amplitudes given by the matrix elements of the corresponding operators; (iii) to better understand the influence of electronic correlations on the lattice structure we will generalize the dynamical mean-field approach to treat electronic and structural properties of correlated materials on the same footing. The latter subproject is expected to lead to a general computational scheme which is able to perform structural optimizations and compute the dynamical lattice properties of correlated materials.