Occupation matrix control of d- and f-electron localisations using DFT + U.
Citation:
Allen JP, Watson GW, Occupation matrix control of d- and f-electron localisations using DFT + U., Physical chemistry chemical physics : PCCP, 16, 39, 2014, 21016-31Download Item:
c4cp01083c.pdf (PDF) 4.413Mb
Abstract:
The use of a density functional theory methodology with on-site corrections (DFT +
U
) has been
repeatedly shown to give an improved description of localised d and f states over those predicted with a
standard DFT approach. However, the localisation of electrons also carries with it the problem of
metastability, due to the possible occupation of different orbitals and different locations. This study
details the use of an occupation matrix control methodology for simulating localised d and f states with
a plane-wave DFT +
U
approach which allows the user to control both the site and orbital localisation.
This approach is tested for orbital occupation using octahedral and tetrahedral Ti(
III
) and Ce(
III
) carbonyl
clusters and for orbital and site location using the periodic systems anatase-TiO
2
and CeO
2
. The periodic cells are tested by the addition of an electron and through the formation of a neutral oxygen
vacancy (leaving two electrons to localise). These test systems allow the successful study of orbital
degeneracies, the presence of metastable states and the importance of controlling the site of
localisation within the cell, and it highlights the use an occupation matrix control methodology can have
in electronic structure calculations.
Sponsor
Grant Number
Engineering and Physical Sciences Research Council (EPSRC)
EP/L000202
European Union Framework Programme 7 (FP7)
CM1104
Science Foundation Ireland (SFI)
09/RFP/MTR2274
Author's Homepage:
http://people.tcd.ie/watsongDescription:
PUBLISHED
Author: WATSON, GRAEME
Type of material:
Journal ArticleCollections:
Series/Report no:
Physical chemistry chemical physics : PCCP16
39
Availability:
Full text availableKeywords:
density functional theory methodologySubject (TCD):
Nanoscience & Materials , Catalysis , Denisty functional theory , Theoretical chemistryDOI:
http://dx.doi.org/10.1039/c4cp01083cISSN:
1463-9076Licences: