Benchmarking the fundamental electronic properties of small TiO2 nanoclusters by GW and coupled cluster theory calculations
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
We study the vertical and adiabatic ionization potentials and electron affinities of bare and hydroxylated TiO2 nanoclusters, as well as their fundamental gap and exciton binding energy values, to understand how the clusters’ electronic properties change as a function of size and hydroxylation. In addition, we have employed a range of many-body methods; including G0W0, qsGW, EA/IP-EOM-CCSD, and DFT (B3LYP, PBE), to compare the performance and predictions of the different classes of methods. We demonstrate that, for bare clusters, all many-body methods predict the same trend with cluster size. The highest occupied and lowest unoccupied DFT orbitals follow the same trends as the electron affinity and ionization potentials predicted by the many-body methods, but are generally far too shallow and deep respectively in absolute terms. In contrast, the ΔDFT method is found to yield values in the correct energy window. However, its predictions depend upon the functional used and do not necessarily follow trends based on the many-body methods. Adiabatic potentials are predicted to be similar to their vertical counterparts and holes found to be trapped more strongly than excess electrons. The effect of hydroxylation on the clusters is to open up both the optical and fundamental gap. Finally, a simple microscopic explanation for the observed trends with cluster size and upon hydroxylation is proposed in terms of the onsite electrostatic potential.
Date Issued
2017-08-01
Date Acceptance
2017-05-24
Citation
Journal of Chemical Theory and Computation, 2017, 13 (8), pp.3814-3828
ISSN
1549-9618
Publisher
American Chemical Society
Start Page
3814
End Page
3828
Journal / Book Title
Journal of Chemical Theory and Computation
Volume
13
Issue
8
Copyright Statement
© 2017 American Chemical Society. ACS AuthorChoice - This is an open access article published under a Creative Commons Attribution (CC-BY) License, which permits unrestricted use, distribution and reproduction in any medium, provided the author and source are cited.
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000407522100032&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Physical Sciences
Chemistry, Physical
Physics, Atomic, Molecular & Chemical
Chemistry
Physics
DENSITY-FUNCTIONAL THEORY
GAUSSIAN-BASIS SETS
CDSE QUANTUM DOTS
EXCITATION-ENERGIES
GREENS-FUNCTION
RUTILE TITANIA
BINDING-ENERGY
GROUND-STATE
ANATASE TIO2
TD-DFT
Publication Status
Published