Effect of Hf doping on He behavior in Tritium storage material ZrCo

Author(s):  
Xianggang Kong ◽  
You Yu ◽  
yanhong shen ◽  
Jiangfeng Song

An exhaustive analysis based on density functional theory (DFT) simulations of the effect of the Hf doping on the helium behavior has been performed in ZrCo. The He impurities have...

Molecules ◽  
2019 ◽  
Vol 24 (19) ◽  
pp. 3565 ◽  
Author(s):  
Ilya Nifant’ev ◽  
Alexander Vinogradov ◽  
Alexey Vinogradov ◽  
Stanislav Karchevsky ◽  
Pavel Ivchenko

Zirconocene-mediated selective dimerization of α-olefins usually occurs when precatalyst (η5-C5H5)2ZrCl2 is activated by minimal excess of methylalumoxane (MAO). In this paper, we present the results of density functional theory (DFT) simulation of the initiation, propagation, and termination stages of dimerization and oligomerization of propylene within the framework of Zr-Al binuclear mechanism at M-06x/DGDZVP level of theory. The results of the analysis of the reaction profiles allow to explain experimental facts such as oligomerization of α-olefins at high MAO/(η5-C5H5)2ZrCl2 ratios and increase of the selectivity of dimerization in the presence of R2AlCl. The results of DFT simulations confirm the crucial role of the presence of chloride in the selectivity of dimerization. The molecular hydrogen was found in silico and proven experimentally as an effective agent that increases the rate and selectivity of dimerization.


Author(s):  
Ramesh Kumar Chitumalla ◽  
Kiduk Kim ◽  
Xingfa Gao ◽  
Joonkyung Jang

By employing periodic-DFT simulations, we unveil that the wet adhesion of mussels onto a hydrophobic graphite surface is significantly strong and is comparable with that on a hydrophilic silica surface.


2009 ◽  
Author(s):  
Thomas R. Mattsson ◽  
Rudolph J. Magyar ◽  
Mark Elert ◽  
Michael D. Furnish ◽  
William W. Anderson ◽  
...  

Crystals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1051
Author(s):  
Emiliano Poli ◽  
Joshua D. Elliott ◽  
Ziwei Chai ◽  
Gilberto Teobaldi

We investigate termination effects in aluminosilicate (AlSi) and aluminogermanate (AlGe) imogolite nanotubes (NTs) by means of semi-local and range-corrected hybrid Density Functional Theory (DFT) simulations. Following screening and identification of the smallest finite model capable of accommodating full relaxation of the NT terminations around an otherwise geometrically and electrostatically unperturbed core region, we quantify and discuss the effects of physical truncation on the structure, relative energy, electrostatics and electronic properties of differently terminated, finite-size models of the NTs. In addition to composition-dependent changes in the valence (VB) and conduction band (CB) edges and resultant band gap (BG), the DFT simulations uncover longitudinal band bending and separation in the finite AlSi and AlGe models. Depending on the given termination of the NTs, such longitudinal effects manifest in conjunction with the radial band separation typical of fully periodic AlSi and AlGe NTs. The strong composition dependence of the longitudinal and radial band bending in AlSi and AlGe NTs suggests different mechanisms for the generation, relaxation and separation of photo-generated holes in AlSi and AlGe NTs, inviting further research in the untapped potential of imogolite compositional and structural flexibility for photo-catalytic applications.


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