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An SCC-DFTB Repulsive Potential for Various ZnO Polymorphs and the ZnO-Water System.

Hellström M, Jorner K, Bryngelsson M, Huber SE, Kullgren J, Frauenheim T, Broqvist P - J Phys Chem C Nanomater Interfaces (2013)

Bottom Line: We have developed an efficient scheme for the generation of accurate repulsive potentials for self-consistent charge density-functional-based tight-binding calculations, which involves energy-volume scans of bulk polymorphs with different coordination numbers.The scheme was used to generate an optimized parameter set for various ZnO polymorphs.By comparison to results obtained at the density functional level of theory, we show that the newly generated repulsive potential is highly transferable and capable of capturing most of the relevant chemistry of ZnO and the ZnO/water interface.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, The Ångström Laboratory, Uppsala University , Box 538, SE-751 21 Uppsala, Sweden.

ABSTRACT
We have developed an efficient scheme for the generation of accurate repulsive potentials for self-consistent charge density-functional-based tight-binding calculations, which involves energy-volume scans of bulk polymorphs with different coordination numbers. The scheme was used to generate an optimized parameter set for various ZnO polymorphs. The new potential was subsequently tested for ZnO bulk, surface, and nanowire systems as well as for water adsorption on the low-index wurtzite (101̅0) and (112̅0) surfaces. By comparison to results obtained at the density functional level of theory, we show that the newly generated repulsive potential is highly transferable and capable of capturing most of the relevant chemistry of ZnO and the ZnO/water interface.

No MeSH data available.


The original znorg-0-1 repulsive potential37 (dashed line) and the new optimized repulsivepotential znopt of this work (solid line) as a functionof Zn–O distance r.
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fig4: The original znorg-0-1 repulsive potential37 (dashed line) and the new optimized repulsivepotential znopt of this work (solid line) as a functionof Zn–O distance r.

Mentions: Our optimized znopt repulsivepotential is compared to the original znorg-0-1 repulsivepotential in Figure 4. At distances longerthan 2 Å, the znopt potential is more repulsivethan the znorg-0-1 potential. Figure 5 shows energy–volume curves calculated using znorg-0-1, znopt, and the reference PBEmethod for the wurtzite and NaCl-type bulk structures of ZnO. Thesewere the polymorphs that were explicitly fitted against in the znopt parametrization procedure. By inspection of Figure 5, it is clear that we have addressed the problemof the too stable NaCl-type structure that plagued the znorg-0-1 repulsive potential. In the following sections, we will show thatwe improve the descriptions of many other types of systems as well.


An SCC-DFTB Repulsive Potential for Various ZnO Polymorphs and the ZnO-Water System.

Hellström M, Jorner K, Bryngelsson M, Huber SE, Kullgren J, Frauenheim T, Broqvist P - J Phys Chem C Nanomater Interfaces (2013)

The original znorg-0-1 repulsive potential37 (dashed line) and the new optimized repulsivepotential znopt of this work (solid line) as a functionof Zn–O distance r.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3753033&req=5

fig4: The original znorg-0-1 repulsive potential37 (dashed line) and the new optimized repulsivepotential znopt of this work (solid line) as a functionof Zn–O distance r.
Mentions: Our optimized znopt repulsivepotential is compared to the original znorg-0-1 repulsivepotential in Figure 4. At distances longerthan 2 Å, the znopt potential is more repulsivethan the znorg-0-1 potential. Figure 5 shows energy–volume curves calculated using znorg-0-1, znopt, and the reference PBEmethod for the wurtzite and NaCl-type bulk structures of ZnO. Thesewere the polymorphs that were explicitly fitted against in the znopt parametrization procedure. By inspection of Figure 5, it is clear that we have addressed the problemof the too stable NaCl-type structure that plagued the znorg-0-1 repulsive potential. In the following sections, we will show thatwe improve the descriptions of many other types of systems as well.

Bottom Line: We have developed an efficient scheme for the generation of accurate repulsive potentials for self-consistent charge density-functional-based tight-binding calculations, which involves energy-volume scans of bulk polymorphs with different coordination numbers.The scheme was used to generate an optimized parameter set for various ZnO polymorphs.By comparison to results obtained at the density functional level of theory, we show that the newly generated repulsive potential is highly transferable and capable of capturing most of the relevant chemistry of ZnO and the ZnO/water interface.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemistry, The Ångström Laboratory, Uppsala University , Box 538, SE-751 21 Uppsala, Sweden.

ABSTRACT
We have developed an efficient scheme for the generation of accurate repulsive potentials for self-consistent charge density-functional-based tight-binding calculations, which involves energy-volume scans of bulk polymorphs with different coordination numbers. The scheme was used to generate an optimized parameter set for various ZnO polymorphs. The new potential was subsequently tested for ZnO bulk, surface, and nanowire systems as well as for water adsorption on the low-index wurtzite (101̅0) and (112̅0) surfaces. By comparison to results obtained at the density functional level of theory, we show that the newly generated repulsive potential is highly transferable and capable of capturing most of the relevant chemistry of ZnO and the ZnO/water interface.

No MeSH data available.