Geometric structure, electronic structure and optical absorption properties of one-dimensional thiolate-protected gold clusters containing a quasi-face-centered-cubic (quasi-fcc) Au-core: a density-functional theoretical study

Nanoscale ◽  
2016 ◽  
Vol 8 (38) ◽  
pp. 17044-17054 ◽  
Author(s):  
Zhongyun Ma ◽  
Pu Wang ◽  
Yong Pei
Keyword(s):  
Electronic Structure ◽  
Optical Absorption ◽  
Geometric Structure ◽  
Density Functional ◽  
Theoretical Study ◽  
Gold Clusters ◽  
Face Centered Cubic ◽  
Absorption Properties ◽  
One Dimensional ◽  
Face Centered

scholarly journals Relativistic Effects on the Equation-of-State of the Light Actinides

2005 ◽  
Vol 893 ◽  
Author(s):  
Alexander Landa ◽  
Per Söderlind
Keyword(s):  
Electronic Structure ◽  
Equation Of State ◽  
Density Functional ◽  
Relativistic Effects ◽  
Model Systems ◽  
Face Centered Cubic ◽  
Electronic Structure Methods ◽  
The Face ◽  
Face Centered ◽  
Structure Calculations

AbstractThe effect of the relativistic spin-orbit (SO)interaction on the bonding in the early actinides has been investigated by means of electronic-structure calculations. Specifically, the equation of state (EOS) for the face-centered cubic (fcc) model systems of these metals has been calculated from the first-principles density-functional (DFT) theory. Traditionally, the SO interaction in electronic-structure methods is implemented as a perturbation to the Hamiltonian that is solved for basis functions that explicitly do not depend on SO coupling. Here this approximation is shown to compare well with the fully relativistic Dirac treatment. It is further shown that SO coupling has a gradually increasing effect on the EOS as one proceeds through the actinides and the effect is diminished as density increases.

Symmetry reduction of δ-plutonium: an electronic-structure effect

2005 ◽  
Vol 893 ◽  
Author(s):  
Kevin T. Moore ◽  
Per Söderlind ◽  
Adam J. Schwartz ◽  
David Laughlin
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Monoclinic Space Group ◽  
Face Centered Cubic ◽  
Functional Theory ◽  
Space Group ◽  
Bond Strengths ◽  
Reduced Space ◽  
Face Centered

AbstractUsing first-principles density-functional theory calculations, we show that the anomalously large anisotropy of δ-plutonium is a consequence of greatly varying bond-strengths between the 12 nearest neighbors. Employing the calculated bond strengths, we expand the tenants of classical crystallography by incorporating anisotropy of chemical bonds, which yields a structure with the monoclinic space group Cm for δ-plutonium rather than face-centered cubic Fm3m. The reduced space group for δ-plutonium enlightens why the ground state of the metal is monoclinic, why distortions of the metal are viable, and has considerable implications for the behavior of the material as it ages. These results illustrate how an expansion of classical crystallography that accounts for anisotropic electronic structure can explain complicated materials in a novel way.

First-principles insights into ammonia decomposition on MoN (0001) surface

2021 ◽  
Author(s):  
kun yuan ◽  
pengju hao ◽  
Xiaolin Li ◽  
Yang Zhou ◽  
jiangbo zhang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Surface Energy ◽  
Geometric Structure ◽  
First Principles ◽  
Density Functional ◽  
Slab Model ◽  
Ammonia Adsorption ◽  
Functional Theory ◽  
Dehydrogenation Mechanism

Density functional theory (DFT) and periodic slab model were used to study the geometric structure, electronic structure and dehydrogenation mechanism of ammonia adsorption on MoN (0001) surface. The surface energy...

Meso-alkynyl corroles and their cobalt(III), manganese(III) and gallium(III) complexes

2020 ◽  
Vol 24 (05n07) ◽  
pp. 737-749
Author(s):  
Michael Haas ◽  
Sabrina Gonglach ◽  
Wolfgang Schöfberger
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Density Functional ◽  
Theoretical Study ◽  
Lumo Energy ◽  
Functional Theory ◽  
Energy Gaps ◽  
Peak Broadening ◽  
Homo And Lumo ◽  
Homo Lumo

We report routes towards synthesis of novel [Formula: see text]-conjugated freebase cobalt, copper, gallium and manganese meso-alkynylcorroles. UV-vis spectra show that extensive peak broadening, red shifts, and changes in the oscillator strength of absorptions increase with the extension of [Formula: see text]-conjugation. Using density functional theory (DFT), we have carried out a first theoretical study of the electronic structure of these metallocorroles. Decreased energy gaps of about 0.3–0.4 eV between the HOMO and LUMO orbitals compared to the corresponding copper, gallium and manganese meso-5,10,15 triphenylcorrole are observed. In all cases, the HOMO energies are nearly unperturbed as the [Formula: see text]-conjugation is expanded. The contraction of the HOMO–LUMO energy gaps is attributed to the lowered LUMO energies.

Theoretical study on the electronic structure, mechanical property, and thermal expansion of yttrium oxysulfide

2015 ◽  
Vol 04 (01) ◽  
pp. 1550004
Author(s):  
Ruipeng Gao ◽  
Yefei Li
Keyword(s):  
Mechanical Property ◽  
Thermal Expansion ◽  
Electronic Structure ◽  
Bulk Modulus ◽  
Density Functional ◽  
Theoretical Study ◽  
Spherical Shape ◽  
Weak Anisotropy ◽  
Covalent Bonds ◽  
Very High

The electronic structure, mechanical property and thermal expansion of yttrium oxysulfide are calculated from first-principles using the theory of density functional. The calculated cohesive energy indicates its thermodynamic stable nature. From bond structure, the calculated bandgap is obtained as 2.7 eV; and strong covalent bonds exist between Y and O atoms intra 2D [ Y – O ] layer in material, while relatively weak covalent bonds also exist inter 2D [ Y – O ] layer and S atoms. From simulation, it is found that the bulk modulus is about 119.4 GPa for the elastic constants, and the bulk modulus shows weak anisotropy because the surface contours of them are close to a spherical shape. The calculated B/G clearly implies its ductile nature, and the Y 2 O 2 S phase can also be compressed easily. The temperature dependence of thermal expansions is mainly caused by the restoration of thermal energy due to lattice excitations at low temperature. When the temperature is very high, the thermal expansion coefficient increases linearly with temperature increasing. Meanwhile, the heat capacities are also calculated and discussed by thermal expansion and elasticity.

Theoretical study of stability and optical absorption properties of ferroelectric materials ZnXO3 (X=Ge, Sn and Pb)

2020 ◽  
Vol 580 ◽  
pp. 411748
Author(s):  
Xing-Yuan Chen ◽  
Yu-Hua Yang ◽  
Guo-Xia Lai ◽  
Jia Chen ◽  
Wei-Ling Zhu ◽  
...  
Keyword(s):  
Optical Absorption ◽  
Theoretical Study ◽  
Ferroelectric Materials ◽  
Absorption Properties

Electronic Structure and Optical Properties of Cu-Doped SnO2

2014 ◽  
Vol 716-717 ◽  
pp. 20-23
Author(s):  
Min Xu
Keyword(s):  
Density Functional Theory ◽  
Optical Properties ◽  
Absorption Spectrum ◽  
Electronic Structure ◽  
Optical Absorption ◽  
Band Structure ◽  
Density Functional ◽  
Density Of State ◽  
Functional Theory ◽  
Reflectivity Spectrum

based on Density Functional Theory, we investigated the optical structures and the electronic properties of Cu doped SnO2with density of 12.5%, including band structure, the density of state (dos), Dielectric function and optical absorption spectrum. The results show that Fermi level access conduction band gradually with the doped density. It has enhanced the electrical and metal property of material. The peaks of reflectivity spectrum and absorption spectrum correspond density of state.

Theoretical Study of the Electronic Structures of Li-Doped ZnO

2012 ◽  
Vol 535-537 ◽  
pp. 214-218
Author(s):  
Qi Xin Wan ◽  
Jia Yi Chen ◽  
Zhi Hua Xiong ◽  
Dong Mei Li ◽  
Bi Lin Shao ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Density Functional ◽  
Formation Energy ◽  
Lattice Distortion ◽  
Theoretical Study ◽  
Functional Theory ◽  
Li Doping ◽  
The Density Functional Theory ◽  
Doped Zno ◽  
Good Agreement

The first-principles with pseudopotentials method based on the density functional theory was applied to calculate the geometric structure, the formation energy of impurities and the electronic structure of Li-doped ZnO. In the system of Li-doped ZnO, LiZn can not result in lattice distortion. In contrast with that case, LiO and Lii result in lattice distortion after Li doping in ZnO. In Li-doped ZnO, LiO is the most unstable than the other cases. Simultaneously, Lii is more stable than LiZn according to that Lii has smaller formation energy. Furthermore, the electronic structure of Li-doped ZnO indicates that that LiZn behaves as acceptor, while Lii behaves as donor. In conclusion, in Li-doped ZnO, Lii is always in the system to compensate the acceptor. Singly doping Li in ZnO is difficult to gain p-ZnO for the self-compensation. The results are in good agreement with other calculated and experimental results.

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