scholarly journals Acetate ligands determine the crystal structure of CdSe nanoplatelets – a density functional theory study

2016 ◽  
Vol 18 (32) ◽  
pp. 22021-22024 ◽  
Author(s):  
Rik S. Koster ◽  
Changming Fang ◽  
Alfons van Blaaderen ◽  
Marjolein Dijkstra ◽  
Marijn A. van Huis
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Cadmium Selenide ◽  
Crucial Role ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Zinc Blende

Density functional theory calculations show that acetate ligands play a crucial role in stabilising cadmium selenide nanoplatelets in the zinc blende crystal structure.

scholarly journals Study on the adsorption selection of CH$$_4$$ on CuO (110) versus (111) surfaces: a density functional theory study

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Long Lin ◽  
Linwei Yao ◽  
Shaofei Li ◽  
Zhengguang Shi ◽  
Kun Xie ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Adsorption Capacity ◽  
Active Sites ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Density Functional Theory Calculations ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Strong Adsorption ◽  
Selection Of

AbstractFinding the active sites of suitable metal oxides is a key prerequisite for detecting CH$$_4$$ 4 . The purpose of the paper is to investigate the adsorption of CH$$_4$$ 4 on intrinsic and oxygen-vacancies CuO (111) and (110) surfaces using density functional theory calculations. The results show that CH$$_4$$ 4 has a strong adsorption energy of −0.370 to 0.391 eV at all site on the CuO (110) surface. The adsorption capacity of CH$$_4$$ 4 on CuO (111) surface is weak, ranging from −0.156 to −0.325 eV. In the surface containing oxygen vacancies, the adsorption capacity of CuO surface to CH$$_4$$ 4 is significantly stronger than that of intrinsic CuO surface. The results indicate that CuO (110) has strong adsorption and charge transfer capacity for CH$$_4$$ 4 , which may provide experimental guidance.

scholarly journals Selective catalytic reduction of NO with NH3 over Cu-exchanged CHA, GME, and AFX zeolites: a density functional theory study

2021 ◽  
Author(s):  
Pei Zhao ◽  
Bundet Boekfa ◽  
Ken-ichi Shimizu ◽  
Masaru Ogura ◽  
Masahiro Ehara
Keyword(s):  
Density Functional Theory ◽  
Selective Catalytic Reduction ◽  
Density Functional ◽  
Catalytic Reduction ◽  
Density Functional Theory Calculations ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Reduction Of No ◽  
Cage Size

Density functional theory calculations have been applied to study the selectivity caused by the cage size during the selective catalytic reduction of NO by NH3 over the Cu-exchanged zeolites with cha, gme, and aft cages.

scholarly journals The effect of helium nano-bubbles on the structures stability and electronic properties of palladium tritides: a density functional theory study

2014 ◽  
Vol 470 (2171) ◽  
pp. 20140357 ◽  
Author(s):  
N. K. Das ◽  
K. Rigby ◽  
N. H. de Leeuw
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Perfect Lattice ◽  
Helium Atoms ◽  
Helium Clusters ◽  
Octahedral Sites ◽  
Metal Atoms

Density functional theory calculations have been used to study the incorporation of helium in perfect and defect-containing palladium tritides, where we have calculated the energetics of incorporation and the migration behaviour. Helium atoms preferably occupy the octahedral interstitial and substitutional sites in the perfect and Pd vacancy-containing tritides, respectively. The energetics reveal that helium clusters can form in the lattice, which displace the Pd metal atoms. The defective lattice shows less expansion compared with the perfect lattice, which can accommodate the helium less easily. The path from octahedral–tetrahedral–octahedral sites is the lowest energy pathway for helium diffusion, and the energetics indicate that the helium generated from tritium decay can accumulate in or near the octahedral sites. Density of states analyses shows the hybridization between palladium d and tritium s orbitals and repulsion between palladium d and helium s orbitals, which can distort the lattice as a result of generating localized stress.

The crystal structure of Na(NH4)Mo3O10·H2O

2017 ◽  
Vol 32 (2) ◽  
pp. 140-147 ◽  
Author(s):  
Joel W. Reid ◽  
James A. Kaduk ◽  
Jeremy A. Olson
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Rietveld Refinement ◽  
Software Package ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Parallel Tempering ◽  
Powder Diffraction Data ◽  
Functional Theory ◽  
Synchrotron Powder Diffraction

The crystal structure of Na(NH4)Mo3O10·H2O has been solved by parallel tempering using the FOX software package with synchrotron powder diffraction data obtained from beamline 08B1-1 at the Canadian Light Source. Rietveld refinement, performed with the software package GSAS, yielded orthorhombic lattice parameters of a = 13.549 82(10), b = 7.618 50(6), and c = 9.302 74(7) Å (Z = 4, space group Pnma). The structure is composed of molybdate chains running parallel to the b-axis. The Rietveld refinement results were compared with density functional theory calculations performed with CRYSTAL14, and show excellent agreement with the calculated structure.

Oxides, Silicides, and Silicates of Zirconium and Hafnium; Density Functional Theory Study

2002 ◽  
Vol 716 ◽  
Author(s):  
Maciej Gutowski ◽  
John E. Jaffe ◽  
Chun-Li Liu ◽  
Matt Stoker ◽  
Anatoli Korkin
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Gate Dielectric ◽  
Density Functional Theory Calculations ◽  
Heat Of Formation ◽  
Density Functional Theory Study ◽  
Functional Theory ◽  
Exchange Correlation ◽  
The Difference ◽  
Constituent Elements

AbstractIt is known that the chemistries of hafnium and zirconium are more nearly identical than for any other two congeneric elements. Thus, both zirconia and hafnia, with the dielectric constant K > 20, have emerged as potential replacements for silica (K = 3.9) as a gate dielectric. We report an important difference between the zirconia/Si and hafnia/Si interfaces based on density functional theory calculations with the Perdew-Wang 91 exchange-correlation functional on the oxides, silicides, and silicates of Zr and Hf. The zirconia/Si interface has been found to be unstable with respect to formation of silicides whereas the hafnia/Si interface is stable. The difference between the two interfaces results from the fact that HfO2 is more stable than ZrO2 (i.e. has a larger heat of formation from its constituent elements) by more than 53 kJ/mol. The hafnium silicides, on the other hand, are less stable than zirconium silicides by ca. 20 kJ/mol.

Energetics of Protonic Species in Yttrium-doped Barium Zirconate: A Density Functional Theory Study

2013 ◽  
Vol 1495 ◽  
Author(s):  
Massimo Malagoli ◽  
M.L. Liu ◽  
Hyeon Cheol Park ◽  
Angelo Bongiorno
Keyword(s):  
Density Functional Theory ◽  
Energy Cost ◽  
Direct Contact ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Barium Zirconate ◽  
Density Functional Theory Study ◽  
Surface Layers ◽  
Functional Theory

ABSTRACTDensity functional theory calculations are used to study the equilibrium energetics of protons on the surface and in the bulk of Y-doped BaZrO3. It is shown that protonic species in direct contact with Y dopants have energies lower than in perfect BaZrO3 by up to 0.4 eV. This energetic stabilization is achieved when the protonic species is in direct contact with two Y dopants. On the (001) surface of BaZrO3, protonic species are found to be energetically more stable than in the bulk by 1.1 eV and 1.6 eV on the BaO and ZrO2 surface terminations, respectively. At these terminations, the energy of protons recover the bulk value after penetrating three surface layers, and the energy cost associated with bulk incorporation is larger than 1 eV.

scholarly journals Synthesis, Characterization, and Crystal Structure Determination of a New Lithium Zinc Iodate Polymorph LiZn(IO3)3

Crystals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 464 ◽  
Author(s):  
Hebboul ◽  
Galez ◽  
Benbertal ◽  
Beauquis ◽  
Mugnier ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Density Functional Theory ◽  
Density Functional ◽  
Second Harmonic ◽  
Infrared Absorption Spectrum ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
Space Group ◽  
X Ray ◽  
Cell Parameters

Synthesis and characterization of anhydrous LiZn(IO3)3 powders prepared from an aqueous solution are reported. Morphological and compositional analyses were carried out by using scanning electron microscopy and energy-dispersive X-ray measurements. The synthesized powders exhibited a needle-like morphology after annealing at 400 °C. A crystal structure for the synthesized compound was proposed from powder X-ray diffraction and density-functional theory calculations. Rietveld refinements led to a monoclinic structure, which can be described with space group P21, number 4, and unit-cell parameters a = 21.874(9) Å, b = 5.171(2) Å, c = 5.433(2) Å, and  = 120.93(4)°. Density-functional theory calculations supported the same crystal structure. Infrared spectra were also collected, and the vibrations associated with the different modes were discussed. The non-centrosymmetric space group determined for this new polymorph of LiZn(IO3)3, the characteristics of its infrared absorption spectrum, and the observed second-harmonic generation suggest it is a promising infrared non-linear optical material.

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