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

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...

Author(s):  
Emiliana-Laura Andreici Eftimie ◽  
Nicolae M. Avram ◽  
Christian Jelsch ◽  
Mirela Nicolov

The present paper reports a theoretical investigation based on first-principles density functional theory calculations to predict the external morphology of the tetragonal GdVO4 crystal from its internal structure. The Bravais–Friedel–Donnay–Harker (BFDH) method, attachment energy (AE) method and surface energy (SE) method were used in this study. Slice energies (cohesive, attachment and specific surface) of the three main crystal faces having (110), (101) and (200) orientation and their d hkl thicknesses were computed using CRYSTAL17 code, in the frame of a 2D periodic slab model. The relative growth rate (R hkl ) and the morphological importance (MI hkl ) for each unrelaxed and relaxed (hkl) face of interest were determined. Consequently, the crystal shapes predicted based upon BFDH, AE and SE methods were represented by the Wulff construction. The results of the morphology crystal predictions, based on the above methods, were compared both against each other and against the experimentally observed morphologies. A quite satisfactory agreement between the predicted and observed crystal morphologies is noticed.


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.


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.


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 ◽  
Author(s):  
Deepti Maikhuri ◽  
Jaiparkash Jaiparkash ◽  
Haider Abbas

Abstract We present a comprehensive first-principles study of the electronic structure of graphene sheet with periodic vacancy. We report the structural, electronic, and magnetic properties of the graphene sheet with periodic vacancy that possess 48 C & 28 H atoms. Computational analysis based on density functional theory predicts that the periodic vacancy can modulate the properties of graphene sheet. Results show that periodic vacancies lead to the manipulation of band gap & could be utilized to tailor the electronic properties of the sheet. Also, it is found that, the graphene sheet with periodic vacancy is non-magnetic in nature.


RSC Advances ◽  
2017 ◽  
Vol 7 (63) ◽  
pp. 39546-39555 ◽  
Author(s):  
Ming-Yang Liu ◽  
Yang Huang ◽  
Qing-Yuan Chen ◽  
Ze-Yu Li ◽  
Chao Cao ◽  
...  

Based on first-principles density functional theory calculations, we systemically study the properties of two-dimensional buckled single-layer bismuth (b-bismuthene).


2017 ◽  
Vol 19 (42) ◽  
pp. 28928-28935 ◽  
Author(s):  
Ya Yang ◽  
Jihua Zhang ◽  
Shunbo Hu ◽  
Yabei Wu ◽  
Jincang Zhang ◽  
...  

First principles calculations based on density functional theory were performed to study the electronic structure and magnetic properties of β-Ga2O3 in the presence of cation vacancies.


RSC Advances ◽  
2014 ◽  
Vol 4 (96) ◽  
pp. 53570-53574 ◽  
Author(s):  
Yin Wei ◽  
Hongjie Wang ◽  
Xuefeng Lu ◽  
Jiangbo Wen ◽  
Min Niu ◽  
...  

Electronic structure and optical properties of silicon nitride adsorbed by rare earths are explored by density functional theory.


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