Network


Latest external collaboration on country level. Dive into details by clicking on the dots.

Hotspot


Dive into the research topics where D.-B. Zhang is active.

Publication


Featured researches published by D.-B. Zhang.


Applied Physics Letters | 2010

Wavelike rippling in multiwalled carbon nanotubes under pure bending

I. Nikiforov; D.-B. Zhang; Richard D. James; Traian Dumitrică

Objective molecular dynamics is used to systematically investigate elastic bending in carbon nanotubes up to 4.2 nm in diameter. A contrasting behavior is revealed: While single-wall tubes buckle in a gradual way, with a clear intermediate regime before they fully buckle, multiwalled tubes with closed cores exhibit a rate- and size-independent direct transition to an unusual wavelike mode with a 1 nm characteristic length. This rippling mode has a nearly-linear bending response and causes a ∼35% reduction in the stiffness of the thickest multiwalled tubes.


Journal of Chemical Physics | 2008

Stability of polycrystalline and wurtzite Si nanowires via symmetry-adapted tight-binding objective molecular dynamics

D.-B. Zhang; M. Hua; Traian Dumitrică

The stability of the most promising ground state candidate Si nanowires with less than 10 nm in diameter is comparatively studied with objective molecular dynamics coupled with nonorthogonal tight-binding and classical potential models. The computationally expensive tight-binding treatment becomes tractable due to the substantial simplifications introduced by the presented symmetry-adapted scheme. It indicates that the achiral polycrystalline of fivefold symmetry and the wurtzite wires of threefold symmetry are the most favorable quasi-one-dimensional Si arrangements. Quantitative differences with the classical model description are noted over the whole diameter range. Using a Wulff energy decomposition approach it is revealed that these differences are caused by the inability of the classical potential to accurately describe the interaction of Si atoms on surfaces and strained morphologies.


Physical Review Letters | 2014

Phonon Quasiparticles and Anharmonic Free Energy in Complex Systems

D.-B. Zhang; Tao Sun; Renata M. Wentzcovitch

We use a hybrid strategy to obtain anharmonic frequency shifts and lifetimes of phonon quasiparticles from first principles molecular dynamics simulations in modest size supercells. This approach is effective irrespective of crystal structure complexity and facilitates calculation of full anharmonic phonon dispersions, as long as phonon quasiparticles are well defined. We validate this approach to obtain anharmonic effects with calculations in MgSiO3 perovskite, the major Earth forming mineral phase. First, we reproduce irregular thermal frequency shifts of well characterized Raman modes. Second, we combine the phonon gas model (PGM) with quasiparticle frequencies and reproduce free energies obtained using thermodynamic integration. Combining thoroughly sampled quasiparticle dispersions with the PGM we then obtain first-principles anharmonic free energy in the thermodynamic limit (N→∞).


Physical Review B | 2009

Electromechanical characterization of carbon nanotubes in torsion via symmetry adapted tight-binding objective molecular dynamics

D.-B. Zhang; Richard D. James; Traian Dumitrica


Physical Review Letters | 2010

Helical Nanotube Structures of MoS2 with Intrinsic Twisting: An Objective Molecular Dynamics Study

D.-B. Zhang; Traian Dumitrică; Gotthard Seifert


Physical Review B | 2014

Dynamic stabilization of cubic CaSi O3 perovskite at high temperatures and pressures from ab initio molecular dynamics

Tao Sun; D.-B. Zhang; Renata M. Wentzcovitch


Physical Review B | 2011

Routes to identification of intrinsic twist in helical MoS2 nanotubes by electron diffraction and annular dark-field scanning transmission electron microscopy imaging

A. Mittal; D.-B. Zhang; C. Teresi; T. Dumitricǎ; K. A. Mkhoyan


Journal of Physical Chemistry Letters | 2011

Screw dislocations in 〈100〉 silicon nanowires: An objective molecular dynamics study

Ilia Nikiforov; D.-B. Zhang; Traian Dumitrică


Physical Review B | 2012

Role of effective tensile strain in electromechanical response of helical graphene nanoribbons with open and closed armchair edges

D.-B. Zhang; Traian Dumitrică


Journal of Chemical Physics | 2011

Note: the role of Peierls-like distortions in the modification of electronic bandgaps of graphene nanoribbons under uniaxial strain.

D.-B. Zhang; Traian Dumitrică

Collaboration


Dive into the D.-B. Zhang's collaboration.

Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar
Top Co-Authors

Avatar

Tao Sun

Chinese Academy of Sciences

View shared research outputs
Top Co-Authors

Avatar

A. Mittal

University of Minnesota

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

I. Nikiforov

University of Minnesota

View shared research outputs
Top Co-Authors

Avatar
Top Co-Authors

Avatar

M. Hua

University of Minnesota

View shared research outputs
Top Co-Authors

Avatar

S. G. Hao

University of Minnesota

View shared research outputs
Researchain Logo
Decentralizing Knowledge