Supercell size scaling of density functional theory formation energies of charged defects

2009 ◽  
Vol 79 (2) ◽  
Author(s):  
N. D. M. Hine ◽  
K. Frensch ◽  
W. M. C. Foulkes ◽  
M. W. Finnis
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Theory Formation ◽  
Size Scaling ◽  
Charged Defects ◽  
Formation Energies

A complete ab initio thermodynamic and kinetic catalogue of the defect chemistry of hematite α-Fe2O3, its cation diffusion, and sample donor dopants

2021 ◽  
Author(s):  
Shehab Shousha ◽  
Sarah Khalil ◽  
Mostafa Youssef
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Defect Formation ◽  
Defect Chemistry ◽  
Cation Diffusion ◽  
Functional Theory ◽  
Migration Barriers ◽  
Hubbard U ◽  
And Migration ◽  
Formation Energies

This paper studies comprehensively the defect chemistry and cation diffusion in α-Fe2O3. Defect formation energies and migration barriers are calculated using density functional theory with a theoretically calibrated Hubbard U...

Oxygen vacancy migration in CSZ using density functional theory

2008 ◽  
Vol 1122 ◽  
Author(s):  
Byeong-Eon Lee ◽  
Dae-Hee Kim ◽  
Yeong-Cheol Kim
Keyword(s):  
Density Functional Theory ◽  
Oxygen Vacancy ◽  
Density Functional ◽  
Oxygen Vacancies ◽  
Nearest Neighbor ◽  
Functional Theory ◽  
The Third ◽  
Vacancy Migration ◽  
Neighbor Site ◽  
Formation Energies

AbstractWe studied oxygen migration in calcia-stabilized cubic zirconia (CSZ) using density functional theory. A Ca atom was substituted for a Zr atom in a 2×2×2 ZrO2 cubic supercell, and an oxygen vacancy was produced to satisfy the charge neutrality condition. We found that the formation energies of an oxygen vacancy, as a function of its location with respect to the Ca atom, were varied. The relative formation energies of the oxygen vacancies located at the first-, second-, third-, and fourth-nearest-neighbors were 0.0, −0.07, 0.19, and 0.19 eV, respectively. Therefore, the oxygen vacancy located at the second-nearest-neighbor site of the Ca atom was the most favorable, the oxygen vacancy located at the first-nearest-neighbor site was the second most favorable, and the oxygen vacancies at the third- and fourth-nearest-neighbor sites were the least favorable. We also calculated the energy barriers for the oxygen vacancy migration between oxygen sites. The energy barriers between the first and the second nearest sites, the second and third nearest sites, and the third and fourth nearest sites were 0.11, 0.46, and 0.23 eV, respectively. Therefore, the oxygen vacancies favored the first- and second-nearest-neighbor oxygen sites when they drifted under an electric field.

scholarly journals Supramolecular Complexes of Cucurbiturils with Second Group Metal Salts and Hydrates and Histamine

INEOS OPEN ◽  
2021 ◽  
Vol 4 ◽  
Author(s):  
Yu. A. Borisov ◽  
◽  
S. S. Kiselev ◽  
Keyword(s):  
Aqueous Solution ◽  
Density Functional Theory ◽  
Density Functional ◽  
Metal Salts ◽  
Supramolecular Complexes ◽  
Water Molecules ◽  
Functional Theory ◽  
Guest Molecules ◽  
First Time ◽  
Formation Energies

The interaction of cucurbiturils (Q6, Q7, and Q8) with Ca and Ba chlorides and iodides are studied for the first time by density functional theory. The thermodynamic parameters for the formation of host–guest complexes are calculated. The structures of complexes of Q6 and Q7 with one and two guest molecules are established. The energy parameters for the transfer of Be2+ and Ba2+ cations from an aqueous solution into the cavity of Q7 containing n water molecules are defined. The dependences of the formation energies for complexes Q7WnBe2+ and Q7WnBa2+ on the number of water molecules are shown to be parabolic, with the energy minima at n = 5 and n = 6, respectively. It is found that Q7 can form in an aqueous solution supramolecular complexes with protonated histamine (HA) and neutral histamine in the presence of Ca2+ ions.

First-principles study of phase stability, electronic and mechanical properties of plutonium sub-oxides

2019 ◽  
Vol 21 (30) ◽  
pp. 16818-16829 ◽  
Author(s):  
P. S. Ghosh ◽  
A. Arya
Keyword(s):  
Mechanical Properties ◽  
Density Functional Theory ◽  
Phase Stability ◽  
First Principles ◽  
Density Functional ◽  
Functional Theory ◽  
First Principles Study ◽  
Hubbard Parameter ◽  
Formation Energies

Formation energies of PuO2, α-Pu2O3 and sub-oxides PuO2−x (0.0 < x < 0.5) are determined using density functional theory employing generalised gradient approximation corrected with an effective Hubbard parameter.

ACHIEVING P-TYPE SEMICONDUCTING ZnO NANOWIRES VIA DONOR ADSORPTION

2013 ◽  
Vol 12 (03) ◽  
pp. 1350014
Author(s):  
DIHUA WU ◽  
ZHEN ZHOU
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electronic Devices ◽  
Zno Nanowires ◽  
Facile Synthesis ◽  
Functional Theory ◽  
Synthesis Route ◽  
Density Functional Theory Computations ◽  
P Type ◽  
Formation Energies

The difficulty of achieving p-type conductance has severely limited the application of ZnO to electronic devices. In this work, we propose a simple and effective way to achieving p-type semiconducting ZnO nanowires (NWs) through density functional theory computations. Adsorption of tetrathiafulvalene (TTF) during synthetic procedures leads to lower formation energies, and accordingly higher concentration of p-type defects; after the formation of ZnO NWs and the desorption of TTF, p-type ZnO NWs can be achieved. Also, we present a facile synthesis route on basis of previous experiments, which provides some guidance for the realization of p-type ZnO NWs.

Deep Level Formation in Undoped and Oxygen-Doped GaN

2000 ◽  
Vol 639 ◽  
Author(s):  
J. M. Gregie ◽  
R. Y. Korotkov ◽  
B. W. Wessels
Keyword(s):  
Density Functional Theory ◽  
Steady State ◽  
Vapor Phase ◽  
Density Functional ◽  
Deep Level ◽  
Deep Level Defect ◽  
Functional Theory ◽  
Organic Vapor ◽  
Metal Organic ◽  
Formation Energies

ABSTRACTDeep level defects in oxygen doped GaN grown by metal-organic vapor phase epitaxy were investigated. Using steady-state photocapacitance (SSPC) spectroscopy, three deep levels with optical ionization energies of 1.0, 1.4, and 3.25 eV were observed in both nominally undoped and oxygen-doped samples. The total deep level defect concentrations ranged from 6 × 1015 cm-3 in undoped films to 3 × 1016 cm-3 in oxygen-doped films. The concentration of the 3.25 eV level defect increased upon oxygen doping, while the concentrationof the 1.0 and 1.4 eV levels were essentially dopant independent. From the measured concentrations the formation energies of the defects were calculated and compared to energies calculated using density functional theory.

scholarly journals Formation energies of rutile metal dioxides using density functional theory

2009 ◽  
Vol 79 (4) ◽  
Author(s):  
J. I. Martínez ◽  
H. A. Hansen ◽  
J. Rossmeisl ◽  
J. K. Nørskov
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Formation Energies ◽  
Metal Dioxides

scholarly journals Electron Self-trapping in Ge2 Se3 and its Role in Ag and Sn Incorporation

2012 ◽  
Vol 1431 ◽  
Author(s):  
Arthur H. Edwards ◽  
Kristy A. Campell ◽  
Andrew C. Pineda
Keyword(s):  
Density Functional Theory ◽  
Electronic Structure ◽  
Dft Calculations ◽  
Fermi Level ◽  
Density Functional ◽  
Functional Theory ◽  
Periodic Model ◽  
Self Trapping ◽  
Formation Energies

ABSTRACTWe present a set of density functional theory (DFT) calculations on the electronic structure of Ag and Sn in Ge2 Se3 in a periodic model. We show that electron self-trapping is a persistent feature in the presence of many defects. Ag and Sn autoionize upon entering Ge2 Se3 becoming Ag+ and Sn2+ , respectively, and the freed electrons self trap at the lowest energy site. Both Ag and Sn can substitute for Ge, and we present formation energies as a function of Fermi level that show that Sn can substantially alter the incorporation of Ag into the Ge2Se3 network.

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