Spin polarization, orbital occupation and band gap opening in vanadium dioxide: The effect of screened Hartree-Fock exchange

Handle URI:
http://hdl.handle.net/10754/563615
Title:
Spin polarization, orbital occupation and band gap opening in vanadium dioxide: The effect of screened Hartree-Fock exchange
Authors:
Wang, Hao; Mellan, Thomas A.; Grau-Crespo, Ricardo; Schwingenschlögl, Udo ( 0000-0003-4179-7231 )
Abstract:
The metal-insulator transition of VO2 so far has evaded an accurate description by density functional theory. The screened hybrid functional of Heyd, Scuseria and Ernzerhof leads to reasonable solutions for both the low-temperature monoclinic and high-temperature rutile phases only if spin polarization is excluded from the calculations. We explore whether a satisfactory agreement with experiment can be achieved by tuning the fraction of Hartree Fock exchange (α) in the density functional. It is found that two branches of locally stable solutions exist for the rutile phase for 12.5%≤α≤20%. One is metallic and has the correct stability as compared to the monoclinic phase, the other is insulating with lower energy than the metallic branch. We discuss these observations based on the V 3d orbital occupations and conclude that α=10% is the best possible choice for spin-polarized VO2 calculations. © 2014 Elsevier B.V. All rights reserved.
KAUST Department:
Physical Sciences and Engineering (PSE) Division; Materials Science and Engineering Program; Computational Physics and Materials Science (CPMS)
Publisher:
Elsevier BV
Journal:
Chemical Physics Letters
Issue Date:
Jul-2014
DOI:
10.1016/j.cplett.2014.05.070
Type:
Article
ISSN:
00092614
Sponsors:
We thank the EPSRC for funding (EP/J001775/1) and for access to the HECToR supercomputer via the Materials Chemistry Consortium (EP/L000202).
Appears in Collections:
Articles; Physical Sciences and Engineering (PSE) Division; Materials Science and Engineering Program; Computational Physics and Materials Science (CPMS)

Full metadata record

DC FieldValue Language
dc.contributor.authorWang, Haoen
dc.contributor.authorMellan, Thomas A.en
dc.contributor.authorGrau-Crespo, Ricardoen
dc.contributor.authorSchwingenschlögl, Udoen
dc.date.accessioned2015-08-03T12:04:24Zen
dc.date.available2015-08-03T12:04:24Zen
dc.date.issued2014-07en
dc.identifier.issn00092614en
dc.identifier.doi10.1016/j.cplett.2014.05.070en
dc.identifier.urihttp://hdl.handle.net/10754/563615en
dc.description.abstractThe metal-insulator transition of VO2 so far has evaded an accurate description by density functional theory. The screened hybrid functional of Heyd, Scuseria and Ernzerhof leads to reasonable solutions for both the low-temperature monoclinic and high-temperature rutile phases only if spin polarization is excluded from the calculations. We explore whether a satisfactory agreement with experiment can be achieved by tuning the fraction of Hartree Fock exchange (α) in the density functional. It is found that two branches of locally stable solutions exist for the rutile phase for 12.5%≤α≤20%. One is metallic and has the correct stability as compared to the monoclinic phase, the other is insulating with lower energy than the metallic branch. We discuss these observations based on the V 3d orbital occupations and conclude that α=10% is the best possible choice for spin-polarized VO2 calculations. © 2014 Elsevier B.V. All rights reserved.en
dc.description.sponsorshipWe thank the EPSRC for funding (EP/J001775/1) and for access to the HECToR supercomputer via the Materials Chemistry Consortium (EP/L000202).en
dc.publisherElsevier BVen
dc.titleSpin polarization, orbital occupation and band gap opening in vanadium dioxide: The effect of screened Hartree-Fock exchangeen
dc.typeArticleen
dc.contributor.departmentPhysical Sciences and Engineering (PSE) Divisionen
dc.contributor.departmentMaterials Science and Engineering Programen
dc.contributor.departmentComputational Physics and Materials Science (CPMS)en
dc.identifier.journalChemical Physics Lettersen
dc.contributor.institutionDepartment of Chemistry, University College London, 20 Gordon Street, London WC1H 0AJ, United Kingdomen
dc.contributor.institutionDepartment of Chemistry, University of Reading, Whiteknights, Reading RG6 6AD, United Kingdomen
kaust.authorWang, Haoen
kaust.authorSchwingenschlögl, Udoen
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