Derivation of atomistic models for lattices consisting of weakly overlapping structural elements

Kantorovich, Lev

doi:10.1002/(sici)1097-461x(2000)78:5<306::aid-qua3>3.0.co;2-m

Cited by 11 publications

(4 citation statements)

References 41 publications

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“…This work along with a number of complementary studies (French et al 2001a(French et al ,b, 2003a(French et al ,b, 2004Bromley et al 2003;Catlow et al 2003Catlow et al , 2005aCatlow et al ,b, 2007Catlow et al , 2008Catlow et al , 2010Phala et al 2005;Sokol et al 2007) provided the first comprehensive computational survey of the atomistic and electronic mechanisms involved in methanol synthesis over the surfaces of pure ZnO and metal clusters supported on ZnO. Analogous methods by other groups have proved to be successful and accurate in the study of localized states and processes in a wide range of recent fundamental and applied studies (Nygren et al 1994;Mejias et al 1995;Llusar et al 1996;Rösch et al 1996;San Miguel et al 1998;de Carolis et al 1999;Kantorovich 1999Kantorovich , 2000aSushko et al 1999;Nasluzov et al 2001Nasluzov et al , 2010Karlsen et al 2003;Rivanenkov et al 2003;Danyliv & Kantorovich 2004;Mysovsky et al 2004;Seijo & Barandiarán 2004;Di Valentin et al 2006;Wang & Kantorovich 2006;Danyliv et al 2007;Giordano et al 2007;Sanz & Márquez 2007;Shor et al 2007Shor et al , 2009Kimmel et al 2008;Ramo et al 2008;Swerts et al 2008;He et al 2009;…”

Section: Hydrogen Dissociation Over Oxygen Terminated Polar Surface Omentioning

confidence: 99%

Characterization of hydrogen dissociation over aluminium-doped zinc oxide using an efficient massively parallel framework for QM/MM calculations

et al. 2011

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A task-farm parallelization framework has been implemented in the ChemShell computational chemistry environment to provide a facility for parallelizing common chemical calculations, including finite-difference Hessian evaluation, the nudged elastic band method for reaction path optimization, and population-based methods for global optimization. The optimization methods are provided by a parallel interface to the DL-FIND optimization library. As ChemShell can already exploit parallel external programs for energy and gradient evaluations, the new methods result in a two-level approach to parallelization that gives significantly improved performance for massively parallel calculations. For typical systems, speed-up factors of five to eight times have been observed compared with non-task-farmed calculations. The task-farming version of ChemShell has been used to study the heterolytic dissociation of a hydrogen molecule over a polar oxygen-terminated surface of aluminium-doped zinc oxide using an embedded cluster hybrid QM/MM approach. We calculate a 42 kcal mol −1 heat of reaction and a 30 kcal mol −1 activation energy, which is equivalent to a high backward reaction barrier of 72 kcal mol −1 per H 2 molecule, in close agreement with temperature programmed desorption experiments. The dissociation path includes a stable intermediate comprising a hydride ion in an oxygen vacancy and physisorbed atomic hydrogen.

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Section: Hydrogen Dissociation Over Oxygen Terminated Polar Surface Omentioning

confidence: 99%

Characterization of hydrogen dissociation over aluminium-doped zinc oxide using an efficient massively parallel framework for QM/MM calculations

et al. 2011

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“…From the beginning, a significant challenge of periodic models was their disability to describe charged and excited states of defects as well as their agglomerates; however, these problems, at least at the theoretical level, were formally solved 13–15. At the same time, despite the fast methodological development of cluster models (both embedded and molecular 7) for simulation of defects in solids 16, 17, they still face a serious challenge in the proper description of oxygen vacancies in metal oxides with chemical bonding of a partly covalent nature, especially in ternary (ABO 3 ) and more complicated oxides (both bulk and surface). Thus, for a consistent description of oxygen vacancies in a broad family of metal oxides, we choose here models with periodic boundary conditions 9.…”

Section: Introductionmentioning

confidence: 99%

Periodic models in quantum chemical simulations of F centers in crystalline metal oxides

Zhukovskii

Kotomin

Ėvarestov

et al. 2007

Int J of Quantum Chemistry

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ABSTRACT:We present a survey of recent first principles simulations of the neutral oxygen vacancies (F centers) existing as native or radiation-induced point defects in various crystalline metal oxides in different forms (bulk, bare substrate surface, and on the interface with metal adsorbates). We mainly consider periodic models in calculations of point defects using the metal oxide supercell or cyclic clusters. We compare different formalisms of first principles calculations, mostly the Density Functional Theory (DFT) as implemented in the framework of either localized basis set of atomic orbitals or delocalized basis sets of plane waves. We analyze in detail the structural and electronic properties of F centers in binary oxides of light metals (MgO and Al 2 O 3 ), and ternary metal oxides (SrTiO 3 , BaTiO 3 , PbTiO 3 , KNbO 3 , and PbZrO 3 perovskites). When available, we compare results of ab initio periodic defect calculations with experimental data, results of the first principles cluster calculations (both embedded and molecular) as well as with semi-empirical calculations. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem 107: 2956 -2985, 2007 Key words: ab initio periodic calculations; binary and ternary metal oxides; bulk; bare substrate surfaces; metal/oxide interfaces; neutral F centers (oxygen vacancies); point defect formation and migration; electronic properties of defective metal oxides

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“…[37][38][39][40][41][42][43] Our focus in the present work is on the implementation of this approach in the ChemShell package, 44,45 where the defect and immediately surrounding region (typically ∼100 atoms) are treated at a QM level of theory, using a Gaussian basis set and a hybrid functional for exchange and correlation to determine the electronic structure accurately. This cluster is embedded in a larger region (typically ∼10 000 atoms), which is treated at an MM level of theory using a polarizable shell model, to provide an accurate elastic and dielectric response of the infinite system to defect formation.…”

Section: Introductionmentioning

confidence: 99%

One-dimensional embedded cluster approach to modeling CdS nanowires

Buckeridge

Bromley

Walsh

et al. 2013

The Journal of Chemical Physics

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The Perdew-Burke-Ernzerhof exchange-correlation functional applied to the G2-1 test set using a plane-wave basis set The Journal of Chemical Physics 122, 234102 (2005) We present an embedded cluster model to treat one-dimensional nanostructures, using a hybrid quantum mechanical/molecular mechanical (QM/MM) approach. A segment of the nanowire (circa 50 atoms) is treated at a QM level of theory, using density functional theory (DFT) with a hybrid exchange-correlation functional. This segment is then embedded in a further length of wire, treated at an MM level of theory. The interaction between the QM and MM regions is provided by an embedding potential located at the interface. Point charges are placed beyond the ends of the wire segment in order to reproduce the Madelung potential of the infinite system. We test our model on the ideal system of a CdS linear chain, benchmarking our results against calculations performed on a periodic system using a plane-wave DFT approach, with electron exchange and correlation treated at the same level of approximation in both methods. We perform our tests on pure CdS and, importantly, the system containing a single In or Cu impurity. We find excellent agreement in the determined electronic structure using the two approaches, validating our embedded cluster model. As the hybrid QM/MM model avoids spurious interactions between charged defects, it will be of benefit to the analysis of the role of defects in nanowire materials, which is currently a major challenge using a plane-wave DFT approach. Other advantages of the hybrid QM/MM approach over plane-wave DFT include the ability to calculate ionization energies with an absolute reference and access to high levels of theory for the QM region which are not incorporated in most plane-wave codes. Our results concur with available experimental data.

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Derivation of atomistic models for lattices consisting of weakly overlapping structural elements

Cited by 11 publications

References 41 publications

Characterization of hydrogen dissociation over aluminium-doped zinc oxide using an efficient massively parallel framework for QM/MM calculations

Characterization of hydrogen dissociation over aluminium-doped zinc oxide using an efficient massively parallel framework for QM/MM calculations

Periodic models in quantum chemical simulations of F centers in crystalline metal oxides

One-dimensional embedded cluster approach to modeling CdS nanowires

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