Cs ADSORPTION ON GaAS(001) As-RICH β2 (2×4) AND Ga-RICH (4×2) RECONSTRUCTION PHASES: A FIRST-PRINCIPLES RESEARCH

2020 ◽  
pp. 2150007
Author(s):  
XIAOHUA YU ◽  
HUIXIA SUN ◽  
GUIRONG SHAO

Using plane-wave ultrasoft pseudopotential method based on first-principles density functional theory (DFT), the adsorption of Cs atom on As-rich GaAs(001)[Formula: see text]([Formula: see text]) reconstruction phase and Ga-rich GaAs(001)([Formula: see text]) reconstruction phase are investigated. The adsorption energy, work function, dipole moment, ionicity, band structure and density of state (DOS) of Cs adsorbed GaAs [Formula: see text]([Formula: see text]) and ([Formula: see text]) models are calculated. The stability and electronic structure of Cs adsorbed GaAs [Formula: see text]([Formula: see text]) and ([Formula: see text]) models are compared. Result shows that [Formula: see text]([Formula: see text]) phase is stable than the ([Formula: see text]) phase and after that Cs adsorption [Formula: see text]([Formula: see text]) phase is more beneficial for photoemission.

2014 ◽  
Vol 900 ◽  
pp. 203-208 ◽  
Author(s):  
Ting Ting Shao ◽  
Fu Chun Zhang ◽  
Wei Hu Zhang

The structural, electronic, and optical properties of rutile-type SnO2 are studied by plane-wave pseudopotential density functional theory (DFT) with GGA, LDA, B3LYP and PBE0 respectively. The computing results show that the band gap getting from PBE0 and B3LYP is much more consistent with the available experimental data than that from GGA and LDA, no matter what the latter use ultra-soft pseudopotential or norm conserving pseudopotential. However, the density of state, real part and imaginary part of dielectric function calculating from every type is basically similar in qualitative analysis.


RSC Advances ◽  
2021 ◽  
Vol 11 (38) ◽  
pp. 23477-23490
Author(s):  
Yonggang Wu ◽  
Jihua Zhang ◽  
Bingwei Long ◽  
Hong Zhang

The ZnWO4 (010) surface termination stability is studied using a density functional theory-based thermodynamic approach. The stability phase diagram shows that O-Zn, DL-W, and DL-Zn terminations of ZnWO4 (010) can be stabilized.


2009 ◽  
Vol 1200 ◽  
Author(s):  
Markus E. Gruner

AbstractThis contribution reports static ionic displacements in ferromagnetic disordered Fe70Pd30 alloys obtained by relaxation of the ionic positions of a 108-atom supercell within the framework of density functional theory. Comparison with a simple statistical model based on Lennard-Jones pair interactions reveals that these displacements are significantly larger than can be explained by the different sizes of the elemental constituents. The discrepancies are presumably related to collective displacements of the Fe atoms. Corresponding distortions are experimentally observed for ordered Fe3Pt and predicted by first-principles calculations for all ordered Fe-rich L12 alloys with Ni group elements and originate from details of the electronic structure at the Fermi level.


2021 ◽  
Author(s):  
kun yuan ◽  
pengju hao ◽  
Xiaolin Li ◽  
Yang Zhou ◽  
jiangbo zhang ◽  
...  

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...


2017 ◽  
Vol 19 (23) ◽  
pp. 15021-15029 ◽  
Author(s):  
Yusheng Wang ◽  
Nahong Song ◽  
Min Jia ◽  
Dapeng Yang ◽  
Chikowore Panashe ◽  
...  

First principles calculations based on density functional theory were carried out to study the electronic and magnetic properties of C2N nanoribbons (C2NNRs).


2009 ◽  
Vol 23 (19) ◽  
pp. 2339-2352 ◽  
Author(s):  
LI BIN SHI ◽  
SHUANG CHENG ◽  
RONG BING LI ◽  
LI KANG ◽  
JIAN WEI JIN ◽  
...  

Density of states and band structure of wurtzite ZnO are calculated by the CASTEP program based on density functional theory and plane-wave pseudopotential method. The calculations are carried out in axial and unaxial strains, respectively. The results of density of states in different strains show that the bottom of the conduction band is always dominated by Zn 4s, and the top of valence band is always dominated by O 2p. The variation of the band gap calculated from band structure is also discussed. In addition, p-d repulsion is used in investigating the variation of the top of the valence band in different strains and the results can be verified by electron density difference.


RSC Advances ◽  
2017 ◽  
Vol 7 (60) ◽  
pp. 37815-37822 ◽  
Author(s):  
F. Ersan ◽  
H. Arkin ◽  
E. Aktürk

This paper investigates the effect of point defects of both hole (Ge, Se) and substitution doping of p-block elements, in single-layer b-GeSe, based on first principles plane wave calculations within spin-polarized density functional theory.


2014 ◽  
Vol 716-717 ◽  
pp. 20-23
Author(s):  
Min Xu

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.


2014 ◽  
Vol 510 ◽  
pp. 33-38 ◽  
Author(s):  
F.W. Badrudin ◽  
M.S.A. Rasiman ◽  
M.F.M. Taib ◽  
N.H. Hussin ◽  
O.H. Hassan ◽  
...  

Structural and electronic properties of a new fluorine-free cathode material of polyanionichydroxysulfates, LiFeSO4OH withcaminitestructure are studied using first principles density functional theory. From the calculated result, it reveals that antiferromagnetic configuration is more stable compared to ferromagnetic and non-magnetic configuration. Meanwhile, the density of state calculation divulges that this material exhibited large d-d type of band gap and would behave as a Mott-Hubbard insulator. Thus, this behaviour can lead to poor electronic conductivity.


2013 ◽  
Vol 27 (15) ◽  
pp. 1362017
Author(s):  
LIUXI TAN ◽  
RUI GUO ◽  
SHIZHONG YANG ◽  
EBRAHIM KHOSRAVI ◽  
GUANG-LIN ZHAO ◽  
...  

First principles density functional theory — based (GW) method — was used to simulate the electronic structure of the novel iron-based superconductor K 0.8 Fe 2 Se 2. The calculated band gap of K 0.8 Fe 2 Se 2 at the Γ point is 0.15 eV, which is significantly lower than the 0.61 eV of vacancy free crystal KFe 2 Se 2. The d-orbital of Fe atom is overlapped with the p-orbital of Se atom. Charge density analysis shows strong lattice distortion and vacancy related electric dipole and quadruple near the K vacancy. The reflectivity is anisotropic in three coordinate directions.


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