How To Extract Quantitative Information on Electronic Transitions from the Density Functional Theory “Black Box”

2019 ◽  
Vol 15 (9) ◽  
pp. 4915-4923 ◽  
Author(s):  
Agostino Migliore
2014 ◽  
Vol 68 (5) ◽  
Author(s):  
Sławomir Michalik ◽  
Jan Małecki ◽  
Natalia Młynarczyk

AbstractA combined experimental and computational study of the dinuclear rhenium(V) complex containing (ReO)2(µ-O) core is presented in this article. The solid-state [Re2Cl4(O)2(µ-O)(3,5-lut)4] (3,5-lut = 3,5-dimethylpyridine) complex was characterised structurally (by single crystal X-ray diffraction) and spectroscopically (by IR, NMR, UV-VIS). The electronic structure was examined using the density functional theory (DFT) method. The spin-allowed electronic transitions were calculated using the time-dependent DFT method, and the UV-VIS spectrum was discussed.


2019 ◽  
Vol 31 (02) ◽  
pp. 2050025
Author(s):  
Limin Chen ◽  
Kun Zhang ◽  
Xin Huang ◽  
Yanbin Zhang ◽  
Qiyun Xie ◽  
...  

In this paper, the structural, electronic and absorption properties of 2,2′-iminobis (acetamide oxime) (IBO) under pressure of 0–300[Formula: see text]GPa are calculated by the density functional theory (DFT) calculations. Analysis of the variation trend of lattice constant, bond length and bond angle of IBO under compression conditions, shows there are complex transformations under different pressure. In addition, it is found that the structure of IBO in the [Formula: see text]-axis is stiffer than that along the [Formula: see text]- and [Formula: see text]-axes, which indicates that the crystal has anisotropic compressibility. By analyzing the band structure and the density of states of IBO, it is seen that at 120[Formula: see text]GPa, the electronic structure of IBO changes into metallic system, and becomes more sensitive under compression conditions. The transition between metal and semiconductor occurs again at 150[Formula: see text]Gpa. Finally, at 180[Formula: see text]GPa, the crystal transforms into metal again. The three obvious phase transitions indicate that the structure of IBO becomes more unstable with the increase of pressure. The absorption spectra show that with the increase of pressure, the optical activity of IBO crystal grows higher, and three obvious structural transitions are, respectively, observed at 120, 150 and 180[Formula: see text]GPa.


Author(s):  
I. Yu. Sklyadneva ◽  
Rolf Heid ◽  
Pedro Miguel Echenique ◽  
Evgueni Chulkov

Electron-phonon interaction in the Si(111)-supported rectangular √(7 ) ×√3 phases of In is investigated within the density-functional theory and linear-response. For both single-layer and double-layer √(7 ) ×√3 structures, it...


2020 ◽  
Vol 18 (1) ◽  
pp. 357-368
Author(s):  
Kaiwen Zheng ◽  
Kai Guo ◽  
Jing Xu ◽  
Wei Liu ◽  
Junlang Chen ◽  
...  

AbstractCatechin – a natural polyphenol substance – has excellent antioxidant properties for the treatment of diseases, especially for cholesterol lowering. Catechin can reduce cholesterol content in micelles by forming insoluble precipitation with cholesterol, thereby reducing the absorption of cholesterol in the intestine. In this study, to better understand the molecular mechanism of catechin and cholesterol, we studied the interaction between typical catechins and cholesterol by the density functional theory. Results show that the adsorption energies between the four catechins and cholesterol are obviously stronger than that of cholesterol themselves, indicating that catechin has an advantage in reducing cholesterol micelle formation. Moreover, it is found that the molecular interactions of the complexes are mainly due to charge transfer of the aromatic rings of the catechins as well as the hydrogen bond interactions. Unlike the intuitive understanding of a complex formed by hydrogen bond interaction, which is positively correlated with the number of hydrogen bonds, the most stable complexes (epicatechin–cholesterol or epigallocatechin–cholesterol) have only one but stronger hydrogen bond, due to charge transfer of the aromatic rings of catechins.


2021 ◽  
Author(s):  
Takashi Kurogi ◽  
Keiichi Irifune ◽  
Takahiro Enoki ◽  
Kazuhiko Takai

Reduction of CCl4 by CrCl2 in THF afforded a trinuclear chromium(III) carbyne [CrCl(thf)2)]3(μ3-CCl)(μ-Cl)3. The chlorocarbyne complex reacted with aldehydes to afford chloroallylic alcohols and terminal alkynes. The density functional theory...


2015 ◽  
Vol 17 (34) ◽  
pp. 22448-22454 ◽  
Author(s):  
K. Zberecki ◽  
R. Swirkowicz ◽  
J. Barnaś

Conventional and spin related thermoelectric effects in zigzag boron nitride nanoribbons are studied theoretically within the Density Functional Theory (DFT) approach.


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