eprintid: 637
rev_number: 32
eprint_status: archive
userid: 1
dir: disk0/00/00/06/37
datestamp: 2005-06-14 12:00:00
lastmod: 2021-09-26 23:03:24
status_changed: 2008-01-09 13:20:13
type: article
metadata_visibility: show
item_issues_count: 0
creators_name: Alfe, D
creators_name: Gillan, MJ
title: Schottky defect formation energy in MgO calculated by diffusion Monte Carlo
subjects: 11000
subjects: 10600
divisions: UCL
divisions: B04
divisions: C06
divisions: F57
divisions: F60
keywords: AUGMENTED-WAVE METHOD, MAGNESIUM-OXIDE, IONIC SOLIDS, QUANTUM
abstract: The energetics of point defects in oxide materials plays a major role in determining their high-temperature properties, but experimental measurements are difficult, and calculations based on density functional theory (DFT) are not necessarily reliable. We report quantum Monte Carlo calculations of the formation energy E-S of Schottky defects in MgO, which demonstrate the feasibility of using this approach to overcome the deficiencies of DFT. In order to investigate system-size errors, we also report DFT calculations of E-S on repeating cells of up to similar to 1000 atoms, which indicate that QMC calculations on systems of only 54 atoms should yield high precision. The DFT calculations also provide the relaxed structures used in the variational and diffusion Monte Carlo calculations. For MgO, we find E-S to be in close agreement with results from DFT and from model interaction potentials, and consistent with the scattered experimental values. The prospects for applying the same approach to transition metal oxides such as FeO are indicated.
date: 2005-06
date_type: published
publisher: AMERICAN PHYSICAL SOC
vfaculties: VMPS
vfaculties: VMPS
oa_status: green
primo: open
primo_central: open_green
article_type_text: Article
verified: verified_batch
elements_source: Web of Science
elements_id: 71708
doi: 10.1103/PhysRevB.71.220101
lyricists_name: Alfe, Dario
lyricists_name: Gillan, Michael
lyricists_id: DALFE65
lyricists_id: MJGIL49
full_text_status: public
publication: PHYS REV B
volume: 71
number: 22
article_number: 220101
pagerange: ? - ?
refereed: TRUE
issn: 1098-0121
citation:        Alfe, D;    Gillan, MJ;      (2005)    Schottky defect formation energy in MgO calculated by diffusion Monte Carlo.                   PHYS REV B , 71  (22)    , Article 220101.  10.1103/PhysRevB.71.220101 <https://doi.org/10.1103/PhysRevB.71.220101>.       Green open access   
 
document_url: https://discovery.ucl.ac.uk/id/eprint/637/1/mgo_qmc2.pdf