We present a computational scheme for ab initio total-energy calculations of materials with strongly interacting electrons using a plane-wave basis set. It combines ab initio band structure and dynamical mean-field theory and is implemented in terms of plane-wave pseudopotentials. The present approach allows us to investigate complex materials with strongly interacting electrons and is able to treat atomic displacements, and hence structural transformations, caused by electronic correlations. Here it is employed to investigate two prototypical Jahn-Teller materials, KCuF3 and LaMnO3, in their paramagnetic phases. The computed equilibrium Jahn-Teller distortion and antiferro-orbital order agree well with experiment, and the structural optimization performed for paramagnetic KCuF3 yields the correct lattice constant, equilibrium Jahn-Teller distortion and tetragonal compression of the unit cell. Most importantly, the present approach is able to determine correlation-induced structural transformations, equilibrium atomic positions and lattice structure in both strongly and weakly correlated solids in their paramagnetic phases as well as in phases with long-range magnetic order.
Wannier states of fcc symmetry qualifying paramagnetic NiO to be a Mott insulator
这封信扩展了我最近关于反铁磁NiO的论文[Structural Distortion Stabilizing the Anti-ferromagnetic and Insulating基态of NiO，Symmetry 2020，12（1），56]，其中还包括该化合物的顺磁相。我报告的证据表明，顺磁性NiO具有一个狭窄的，大致半满的能带，产生非绝热的原子状运动提供的基础上，在顺磁性相的莫特绝缘体。虽然在反铁磁相的原子状运动操作是适应的反铁磁状态的对称性，在顺磁相的相关本地化的状态表示的最佳本地化的Wannier函数拥有全fcc对称性的顺磁NiO。非绝热Wannier态是双重简并的，具有类d对称性，并且位于Ni原子上。
Magnetically-Driven Ferroelectric Atomic Displacements in perovskite like YMnO3
磁驱动铁电原子位移的数量级为10 $^{-3} Angstrom have been observed in orthorhombic (perovskite like) YMnO$ _3 $ by a single-crystal synchrotron x-ray diffraction. The refined polar structure shows the characteristic bond alternation driven by the exchange striction in staggered Mn-O-Mn arrays with $ \uparrow \uparrow \downarrow \downarrow $型有序，引起沿a轴的自发极化。第一性原理计算的基础上的贝里相位方法以及实验上细化的晶体结构可以重现所观察到的偏振值。
Terahertz Spin-Orbital Excitations in the paramagnetic state of multiferroic Sr$_2$FeSi$_2$O$_7$
对新型多铁性材料Sr $_2$ FeSi $_2$ O $_7$进行了太赫兹时域光谱研究，发现在磁有序转变温度以上有3种吸收模式。这些吸收模式可以解释为该材料中自旋轨道耦合和晶体场分裂3d $^6$ Fe $^{2+}$基态项之间的光学跃迁。考虑的Fe $^{2+}$网站的压缩四面体环境是至关重要的理解的激发。然而，我们指出，单站点原子图片和实验结果之间的差异。
Electron transfer and ionic displacements at the origin of the 2D electron gas at the LAO/STO interface: Direct measurements with atomic-column spatial resolution
THz Magneto-electric atomic rotations in the chiral compound Ba$_3$NbFe$_3$Si$_2$O$_{14}$
用同步辐射测量方法测量了手性硅酸镓镧$_3$ $_2$ O $_{14}$的太赫兹光谱。两个激发被证明具有不同的性质。第一个，纯磁性，在低温下观察到的磁有序相，并被分配到一个磁振子。第二个persits远到顺磁相，并表现出在略有不同的能量的电和磁活动。这种磁电激发被解释为原子旋转，并需要一个螺旋电极化的强度。
