lattice distortion
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2022 ◽  
Vol 104 ◽  
pp. 236-243
Yuan-Yuan Tan ◽  
Zhong-Jun Chen ◽  
Ming-Yao Su ◽  
Gan Ding ◽  
Min-Qiang Jiang ◽  

2022 ◽  
Vol 210 ◽  
pp. 114470
Pramote Thirathipviwat ◽  
Shigeo Sato ◽  
Gian Song ◽  
Jozef Bednarcik ◽  
Kornelius Nielsch ◽  

2022 ◽  
Maria Storm Thomsen ◽  
Andy Sode Anker ◽  
Laura Kacenauskaite ◽  
Thomas Just Sørensen

Our theoretical treatment of electronic structure in coordination complexes often rests on assumptions of symmetry. Experiments rarely provide fully symmetric systems to study. In solution, fluctuation in solvation, variations in conformation, and even changes in constitution occur and complicates the picture. In crystals, lattice distortion, energy transfer, and phonon quenching is in play, but we are able to have distinct symmetries. Yet the question remains: How is the real symmetry in a crystal compared to ideal symmetries? Moreover, at what level of detail do we need to study a system to determine, if the electronic structure behaves as if it has ideal symmetry? Here, we have revisited the Continues Shape Measurement (CShM) approach developed by Ruiz-Martínez and Alvarez to evaluate the structure of ten-coordinated europium(III) ions in a K5Na[Eu2(SO4)6] structure. By comparing the result of the symmetry deviation analysis to luminescence data, we are able to show the effect of small deviations from ideal symmetry. We suggest using a symmetry deviation value, σideal, determined by using our updated approach to Continues Shape Measurements, where we also align the structure via our AlignIt code. AlignIt includes normalization and relative orientation in the symmetry comparison, and by combining the calculated values with the experimentally determined energy level splitting, we were able create the first point on a scale that can show how close to ideal an experimental structure actually is.

Nanoscale ◽  
2022 ◽  
Zhikai Shi ◽  
Zebin Yu ◽  
Juan Guo ◽  
Ronghua Jiang ◽  
Yanping Hou ◽  

Lattice distortion is an important way to improve the electrocatalytic performance and stability of two-dimensional transition metal materials (2d-TMSs). Herein, a lattice distortion nickel-molybdenum sulfide electrocatalyst on foam nickel (NiMoS4-12/NF)...

2021 ◽  
Vol 29 ◽  
pp. 102760
Xuan Liu ◽  
Nannan Jia ◽  
Songshen Chen ◽  
Liang Wang ◽  
Huibin Ke ◽  

2021 ◽  
Vol 7 (1) ◽  
Lukas Windgätter ◽  
Malte Rösner ◽  
Giacomo Mazza ◽  
Hannes Hübener ◽  
Antoine Georges ◽  

AbstractThe structural phase transition in Ta2NiSe5 has been envisioned as driven by the formation of an excitonic insulating phase. However, the role of structural and electronic instabilities on crystal symmetry breaking has yet to be disentangled. Meanwhile, the phase transition in its complementary material Ta2NiS5 does not show any experimental hints of an excitonic insulating phase. We present a microscopic investigation of the electronic and phononic effects involved in the structural phase transition in Ta2NiSe5 and Ta2NiS5 using extensive first-principles calculations. In both materials the crystal symmetries are broken by phonon instabilities, which in turn lead to changes in the electronic bandstructure also observed in the experiment. A total energy landscape analysis shows no tendency towards a purely electronic instability and we find that a sizeable lattice distortion is needed to open a bandgap. We conclude that an excitonic instability is not needed to explain the phase transition in both Ta2NiSe5 and Ta2NiS5.

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