LiNiO2 (LNO)基态的晶体结构和电子结构长期以来存在着实验与理论计算不一致的争议. 实验上观测到LNO是空间群为 $$R\overline3m$$ 的半导体并且有局部的Jahn-Teller (JT)畸变, 但理论计算却表明它是处于亚稳态的金属并且没有任何的JT畸变. 本文基于杂化密度泛函理论HSE06, 首次模拟了与实验等同浓度(~3%)的Ni/Li反位缺陷对LNO的影响, 发现缺陷能够有效调控LNO中的JT效应. 在LNO中引入Ni/Li反位缺陷后, 其结构发生了局部的JT畸变, 并且其带隙值约为0.5 eV, 这些计算结果都和实验现象非常吻合. Ni/Li反位通过粒径效应和库伦作用, 既能诱发JT畸变, 又能阻碍畸变之间的协同作用, 避免相变到C2/m, 而只产生局部的JT畸变. 本文提出了一种新的策略来解释LNO基态晶体结构和电子结构长期以来的争议, 对推动富镍层状材...

The Jahn-Teller theorem predicts that orbitally degenerate complexes in solids can lower their energy by a distortion which lowers their symmetry. Exact degeneracy is not necessary for this instability; usually it suffices if the actual separation of the energy levels involved is less than the energy reduction which would result if they were exactly degenerate. We discuss various cases of accid...

We show through selected examples, relevant to the physics of fullerene ions, that the presence of a Berry phase in dynamical Jahn-Teller systems does not guarantee the degeneracy of the ground state, contrary to what previously believed. Moreover, we introduce a new class of JahnTeller systems with no Berry phase, as a generalization of the basic icosahedral H ⊗ h case.

We discuss a powerful algorithm for calculating static and dynamic properties of electron– phonon coupled systems with dynamic quantum phonons. The difference between Jahn–Teller polarons present in certain transition metal oxides and simpler Holstein polarons is explored. We calculate the dynamics of polaron formation from a bare injected electron, which has been measured in several recent exp...

In the title compound, [Cu(NO(3))(2)(C(18)H(16)N(2)O(2))], the Cu(II) ion is six-coordinated in a Jahn-Teller-distorted octa-hedral environment defined by two O and two N atoms from the ligand and two O atoms from two monodentate nitrate anions.