STRUCTURAL TRANSITIONS OF BiI3 UNDER PRESSURE

High pressure studies of BiI 3 at 0 K are performed using first-principles pseudopotential calculations within the framework of density functional theory. The calculations indicate that BiI 3 undergoes a structural transition from rhombohedral R-3 phase to monoclinic P2 1/c phase at 7 GPa which is accompanied by a 5.8% volume collapse. In addition, we find that P2 1/c phase prevails about 60 GPa range and transforms to cubic Fm-3m phase at 68 GPa, and finally takes the orthorhombic Pnma phase at high pressures up to 133 GPa. The structural and electronic properties of four competitive structures are also calculated. The analysis of density of states reveals that BiI 3 has semiconductor-metal transition at about 61 GPa, which also demonstrates the metallic nature of both Fm-3m and Pnma phases.

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Electronic structure of cubic BaTbO3 from first-principles pseudopotential calculations

Canadian Journal of Physics ◽

10.1139/p06-008 ◽

2006 ◽

Vol 84 (2) ◽

pp. 115-120 ◽

Cited By ~ 3

Author(s):

G Y Gao ◽

K L Yao ◽

Z L Liu

Keyword(s):

Electronic Structure ◽

First Principles ◽

Density Functional ◽

First Principles Calculations ◽

Generalized Gradient ◽

Functional Theory ◽

Exchange Correlation ◽

Pseudopotential Calculations ◽

Correlation Potential ◽

Density Contour

First-principles calculations of the electronic structure are performed for cubic BaTbO3 using the plane-wave pseudopotential method within the framework of density functional theory and using the generalized gradient approximation for the exchange-correlation potential. Our calculations show that cubic BaTbO3 is metallic, and that this metallic character is mainly governed by the Tb 4f electrons and the hybridization between the Tb 5d and O 2p states. From the analysis of the density of states, band structure, and charge density contour, we find that the chemical bonding between Tb and O is covalent while that between Ba and TbO3 is ionic. PACS Nos.: 71.15.Mb, 71.20.-b

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Thermodynamic Properties of CaSiO3 Perovskite at High Pressure and High Temperature

Zeitschrift für Naturforschung A ◽

10.1515/zna-2009-5-615 ◽

2009 ◽

Vol 64 (5-6) ◽

pp. 399-404 ◽

Cited By ~ 1

Author(s):

Zi-Jiang Liu ◽

Xiao-Ming Tan ◽

Yuan Guo ◽

Xiao-Ping Zheng ◽

Wen-Zhao Wu

Keyword(s):

Thermodynamic Properties ◽

First Principles ◽

Density Functional ◽

High Pressures ◽

Local Density ◽

Harmonic Approximation ◽

Debye Model ◽

Functional Theory ◽

Casio3 Perovskite ◽

First Time

The thermodynamic properties of tetragonal CaSiO3 perovskite are predicted at high pressures and temperatures using the Debye model for the first time. This model combines the ab initio calculations within local density approximation using pseudopotentials and a plane wave basis in the framework of density functional theory, and it takes into account the phononic effects within the quasi-harmonic approximation. It is found that the calculated equation of state is in excellent agreement with the observed values at ambient condition. Based on the first-principles study and the Debye model, the thermal properties including the Debye temperature, the heat capacity, the thermal expansion and the entropy are obtained in the whole pressure range from 0 to 150 GPa and temperature range from 0 to 2000 K.

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HfS2 and TiS2 Monolayers with Adsorbed C, N, P Atoms: A First Principles Study

Catalysts ◽

10.3390/catal10010094 ◽

2020 ◽

Vol 10 (1) ◽

pp. 94

Author(s):

Mailing Berwanger ◽

Rajeev Ahuja ◽

Paulo Cesar Piquini

Keyword(s):

Density Functional Theory ◽

Electronic Properties ◽

Molecular Species ◽

First Principles ◽

Density Functional ◽

2D Materials ◽

Metallic Behavior ◽

Functional Theory ◽

Structural And Electronic Properties ◽

Localized Levels

First principles density functional theory was used to study the energetic, structural, and electronic properties of HfS 2 and TiS 2 materials in their bulk, pristine monolayer, as well as in the monolayer structure with the adsorbed C, N, and P atoms. It is shown that the HfS 2 monolayer remains a semiconductor while TiS 2 changes from semiconductor to metallic behavior after the atomic adsorption. The interaction with the external atoms introduces localized levels inside the band gap of the pristine monolayers, significantly altering their electronic properties, with important consequences on the practical use of these materials in real devices. These results emphasize the importance of considering the interaction of these 2D materials with common external atomic or molecular species.

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THERMODYNAMIC PROPERTIES OF MgSiO3 POST-PEROVSKITE

Modern Physics Letters B ◽

10.1142/s0217984910022391 ◽

2010 ◽

Vol 24 (03) ◽

pp. 315-324

Author(s):

ZI-JIANG LIU ◽

XIAO-WEI SUN ◽

CAI-RONG ZHANG ◽

LI-NA TIAN ◽

YUAN GUO

Keyword(s):

Thermodynamic Properties ◽

First Principles ◽

Density Functional ◽

High Pressures ◽

Local Density ◽

Harmonic Approximation ◽

Debye Model ◽

Functional Theory ◽

High Pressures And Temperatures ◽

First Time

The thermodynamic properties of MgSiO 3 post-perovskite are predicted at high pressures and temperatures using the Debye model for the first time. This model combines with ab initio calculations within local density approximation using pseudopotentials and a plane wave basis in the framework of density functional theory, and it takes into account the phononic effects within the quasi-harmonic approximation. It is found that the calculated equation of state of MgSiO 3 post-perovskite is in excellent agreement with the latest observed values. Based on the first-principles study and the Debye model, the thermal properties including the Debye temperature, the heat capacity, the thermal expansion, and the entropy are obtained in the whole pressure range from 0 to 150 GPa and temperature range from 0 to 2000 K.

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Unexpected superhard phases of niobium triborides: first-principles calculations

RSC Advances ◽

10.1039/c6ra05162f ◽

2016 ◽

Vol 6 (54) ◽

pp. 49214-49220 ◽

Cited By ~ 3

Author(s):

Xiaofeng Li ◽

Junyi Du

Keyword(s):

Density Functional Theory ◽

First Principles ◽

Density Functional ◽

High Pressures ◽

Density Functional Theory Calculations ◽

Search Method ◽

First Principles Calculations ◽

Functional Theory ◽

Swarm Optimization ◽

Structure Search

Using an unbiased structure search method based on particle-swarm optimization algorithms in combination with density functional theory calculations, we investigate the phase stability and electronic properties of NbB3 under high pressures.

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Fine tuning the band-gap of graphene by atomic and molecular doping: a density functional theory study

RSC Advances ◽

10.1039/c6ra04782c ◽

2016 ◽

Vol 6 (61) ◽

pp. 55990-56003 ◽

Cited By ~ 27

Author(s):

Akhtar Hussain ◽

Saif Ullah ◽

M. Arshad Farhan

Keyword(s):

Density Functional Theory ◽

First Principles ◽

Density Functional ◽

Fine Tuning ◽

Density Functional Theory Study ◽

Functional Theory ◽

Structural And Electronic Properties ◽

Doped Graphene ◽

Molecular Doping ◽

Co Doped

First-principles density functional theory (DFT) based calculations were carried out to investigate the structural and electronic properties of beryllium and nitrogen co-doped and BeN/BeO molecules-doped graphene systems.

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First-Principles Study of TiC(111) Surface

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.229-231.82 ◽

2012 ◽

Vol 229-231 ◽

pp. 82-86 ◽

Cited By ~ 1

Author(s):

Li Wang ◽

Teng Fang ◽

Jian Hong Gong

Keyword(s):

First Principles ◽

Density Functional ◽

Chemical Potential ◽

Charge Accumulation ◽

Ab Initio Method ◽

Functional Theory ◽

Structural And Electronic Properties ◽

Full Relaxation ◽

Energy Plane ◽

Large Charge

The structural and electronic properties of TiC(111) surfaces are calculated using the first-principles total-energy plane-wave pseudopotential method based on density functional theory. As a polar surface, (111) surface shows large charge depletion in the upper part of the atoms, while charge accumulation happens in the inferior part of the atoms, interlayer Ti-C chemical bonds are reinforced and the outermost interlayer distances are largely reduced. Meanwhile, the charge accumulation and depletion for Ti-terminated surface is more than that for C-terminated surface on the same position of the two slabs after full relaxation. The surface energy of C-terminated surface is in the range from 7.61 to 9.83 J/m2, much larger than that of Ti-terminated surface from 3.13 to 1.35 J/m2, and the Ti-terminated surface is thermodynamically more favorable over all of the range of (chemical potential of TiC slab). This present work makes a beneficial attempt at exploring TiC surface as an ab initio method for studying possible nucleation mechanism of Aluminum on it.

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First Principles Study on Structural and Electronic Properties of LiFeSO4OH Cathode Material for Lithium Ion Batteries

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.510.33 ◽

2014 ◽

Vol 510 ◽

pp. 33-38 ◽

Cited By ~ 1

Author(s):

F.W. Badrudin ◽

M.S.A. Rasiman ◽

M.F.M. Taib ◽

N.H. Hussin ◽

O.H. Hassan ◽

...

Keyword(s):

Density Functional Theory ◽

Cathode Material ◽

Electronic Properties ◽

First Principles ◽

Density Functional ◽

Electronic Conductivity ◽

Lithium Ion ◽

Density Of State ◽

Functional Theory ◽

Structural And Electronic Properties

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.

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First Principles Study on Structural and Electronic Properties of Cubic (Pm3m) And Tetragonal (P4mm) ATiO3 (A=Pb, Sn)

Scientific Research Journal ◽

10.24191/srj.v17i2.9918 ◽

2020 ◽

Vol 17 (2) ◽

pp. 149

Author(s):

Nurakma Natasya Md Jahangir Alam ◽

Nur Aisyah Ab Malik Marwan ◽

Mohd Hazrie Samat ◽

Muhammad Zamir Mohyedin ◽

Nur Hafiz Hussin ◽

...

Keyword(s):

Cross Section ◽

First Principles ◽

Density Functional ◽

Electronic Band Structure ◽

Ferroelectric Materials ◽

Lead Free ◽

Electronic Band ◽

Functional Theory ◽

First Principles Study ◽

Structural And Electronic Properties

Works are centered on exploring lead-free ferroelectric materials that have a comparable unique ns2 solitary pair electrons with Pb (II), for example, Sn (II) using the first-principles study. All counts were performed dependent on Density Functional Theory (DFT) that has been executed in CASTEP. GGA-PBE displays the most exact qualities for cross-section parameters concerning exploratory qualities for both cubic PbTiO3. In the interim, GGA-PBEsol functional is exact for tetragonal PTO. The electronic band structure and density of states show the presence of hybridizations between anion O 2p and cation Pb 6s/Sn 5s unique solitary pair in tetragonal PTO and SnTO stage.

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Band-gap tuning of graphene by Be doping and Be, B co-doping: a DFT study

RSC Advances ◽

10.1039/c5ra08061d ◽

2015 ◽

Vol 5 (69) ◽

pp. 55762-55773 ◽

Cited By ~ 40

Author(s):

Saif Ullah ◽

Akhtar Hussain ◽

WaqarAdil Syed ◽

Muhammad Adnan Saqlain ◽

Idrees Ahmad ◽

...

Keyword(s):

Density Functional Theory ◽

Dft Calculations ◽

First Principles ◽

Density Functional ◽

Functional Theory ◽

Co Doping ◽

Structural And Electronic Properties ◽

Doped Graphene ◽

Band Gap Tuning ◽

Co Doped

First-principles density functional theory (DFT) calculations were carried out to investigate the structural and electronic properties of beryllium (Be) doped and, Be with boron (B) co-doped graphene systems.

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