scholarly journals First-principles comparative study of perfect and defective CsPbX3 (X = Br, I) crystals

2020 ◽  
Vol 22 (7) ◽  
pp. 3914-3920 ◽  
Author(s):  
R. A. Evarestov ◽  
E. A. Kotomin ◽  
A. Senocrate ◽  
R. K. Kremer ◽  
J. Maier

This paper presents first principles Density Functional Theory hybrid functional calculations of the atomic and electronic structure of perfect CsPbI3, CsPbBr3 and CsPbCl3 crystals, as well as defective CsPbI3 and CsPbBr3 crystals.

RSC Advances ◽  
2020 ◽  
Vol 10 (25) ◽  
pp. 14714-14719
Author(s):  
T. K. Bijoy ◽  
P. Murugan ◽  
Vijay Kumar

We report the results of density functional theory calculations on the atomic and electronic structure of solids formed by assembling A2B2PN (A = Ge and Sn, B = Cl, Br, and I) inorganic double helices.


2001 ◽  
Vol 690 ◽  
Author(s):  
I.I. Oleinik ◽  
E.Y. Tsymbal ◽  
D.G. Pettifor

ABSTRACTThe atomic and electronic structure of Co/SrTiO3/Co (001) magnetic tunnel junctions (MTJs) was investigated by first-principles density-functional theory. We considered different interface terminations and the most stable structure with the TiO2 termination has been identified based on energetics of adhesion. The electronic structure of the TiO2-erminated MTJ shows an exchange coupling between the interface Co and Ti atoms mediated by oxygen. This coupling induces the magnetic moment of 0.25 μB on the interface Ti atom, which is aligned antiparallel to the magnetic moment of the Co layer. We argue that this might cause the inversion of the spin polarization of tunneling across the SrTiO3 barrier that was found in recent experiments.


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...


2018 ◽  
Vol 20 (45) ◽  
pp. 28575-28582 ◽  
Author(s):  
Bhagwati Prasad Bahuguna ◽  
L. K. Saini ◽  
Rajesh O. Sharma ◽  
Brajesh Tiwari

We have investigated the structural, electronic and thermoelectric properties of GaS, GaSe and GaTe monolayers based on the first-principles approach by using density functional theory and the semi-classical Boltzmann transport equation.


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.


2020 ◽  
Vol 22 (18) ◽  
pp. 10295-10304 ◽  
Author(s):  
Moussab Harb ◽  
Luigi Cavallo ◽  
Jean-Marie Basset

The effects of native defects and exposed facets on the thermodynamic stability and photocatalytic characteristics of Ta3N5 for water splitting are studied by applying accurate quantum computations on the basis of density functional theory (DFT) with the range-separated hybrid functional (HSE06).


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.


2021 ◽  
pp. X
Author(s):  
Hongbo TANG ◽  
Qiuyue LI ◽  
Jian ZHOU ◽  
Lihua XIAO ◽  
Ping PENG

Received 03 January 2020; accepted 17 June 2020 We have investigated the optical properties of La (0, 0.125, 0.250) doped YB6 by means of first-principles calculations within the framework of density functional theory. It was found that electronic and optical properties of YB6 crystals varied remarkably when Y atoms were replaced with La atoms. Furthermore, with increasing content of La in YB6 crystals from 12.5 % to 25 % reflectivity and absorption coefficient of near infrared light decreased obviously, while the transmittance was enhanced.


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