نتایج جستجو برای: Density functional tight-binding

تعداد نتایج: 1348279  

پایان نامه :وزارت علوم، تحقیقات و فناوری - پژوهشگاه دانشهای بنیادی (مرکز تحقیقات فیزیک نظری و - پژوهشکده علوم نانو 1392

among the low–dimensional allotropes of carbon, nanotubes and graphene have attracted very much attention from nano–science and nanotechnology specialists. they have been proposed as building blocks in nanometer device engineering. however, these structures are not defect–free. in this thesis, we focused on defective carbon nanotubes and graphene, and studied the effect of couple of very common...

Journal: :Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences 2014

Journal: :Philosophical transactions. Series A, Mathematical, physical, and engineering sciences 2014
Marcus Elstner Gotthard Seifert

This paper reviews the basic principles of the density-functional tight-binding (DFTB) method, which is based on density-functional theory as formulated by Hohenberg, Kohn and Sham (KS-DFT). DFTB consists of a series of models that are derived from a Taylor series expansion of the KS-DFT total energy. In the lowest order (DFTB1), densities and potentials are written as superpositions of atomic ...

Journal: Journal of Nanoanalysis 2017

Extensive urbanization has greatly raised the demand for cleaner coal- and petroleum-derived fuels. Mainly composed of methane, natural gas represents a promising alternative for this purpose, making its storage a significant topic. In the present research, deposition of methane molecules in C60 fullerene was investigated through a combined approach wherein density functional based tight bindin...

Due to the high cost of experimental analyses, researchers used atomistic modeling methods for predicting the mechanical behavior of the materials in the fields of nanotechnology. In the pre-sent study the Self-Consistent Charge Density Functional Tight-Binding (SCC-DFTB) was used to calculate Young's moduli and average potential energy of the straight and curved graphenes with different curvat...

2009
Pekka Koskinen Ville Mäkinen

This article is a pedagogical introduction to density-functional tight-binding (DFTB) method. We derive it from the density-functional theory, give the details behind the tight-binding formalism, and give practical recipes for parametrization: how to calculate pseudo-atomic orbitals and matrix elements, and especially how to systematically fit the short-range repulsions. Our scope is neither to...

Journal: :Journal of the Brazilian Chemical Society 2009

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