scholarly journals Density-Functional and Tight-Binding Theory of Silicene and Silicane

2018 ◽  
pp. 23-41
Author(s):  
V. Zólyomi ◽  
N. D. Drummond ◽  
J. R. Wallbank ◽  
V. I. Fal’ko
Keyword(s):  
Density Functional ◽  
Tight Binding ◽  
Binding Theory

A SELF-CONSISTENT-CHARGE DENSITY-FUNCTIONAL TIGHT-BINDING THEORY BASED MOLECULAR DYNAMICS SIMULATION OF A ZWITTERIONIC GLYCINE IN AN EXPLICIT WATER ENVIRONMENT

2013 ◽  
Vol 12 (04) ◽  
pp. 1350019 ◽  
Author(s):  
Y. ZHAI ◽  
Y. L. ZHAO
Keyword(s):  
Molecular Dynamics ◽  
Amino Acids ◽  
Charge Density ◽  
Density Functional ◽  
Water Environment ◽  
Tight Binding ◽  
Water Molecules ◽  
Binding Theory ◽  
Self Consistent ◽  
The Impact

A zwitterionic glycine (zGLY) is adopted as an example to study the impact of water environment (310 H2O molecules) on the molecular structure and energetics using a self-consistent-charge density-functional tight-binding theory based molecular dynamics (SCC-DFTB/MD) method. It is found that maximal eight hydrogen bonds could be formed simultaneously between eight water molecules and the zGLY. The ability of the COO- terminal to adsorb water molecules is stronger than the [Formula: see text] terminal with respect to hydrogen bonding with more water molecules and exhibits lower adiabatic adsorption energies. The zGLY's intramolecular hydrogen bond appeared unpredictably, without involving any proton transfer and generally helpful for enhancing the system stability. Water molecules play an important role to stabilize the zwitterionic amino acids and restrain the proton migration from the [Formula: see text] to the COO− group. Our results show that the SCC-DFTB/MD method could successfully describe geometry dynamical evolutions and energetics of biomolecules in a nanoscale simulation with the presence of a large number of water molecules. Our study not only verified the feasibility of a QM level methodology for describing the aqueous states of biochemical molecules, but also gave a clear evidence for the impact of water environment on amino acids.

scholarly journals Thermochemical stabilities of giant fullerenes using density functional tight binding theory and isodesmic‐type reactions

2020 ◽  
Vol 42 (4) ◽  
pp. 222-230
Author(s):  
Simone L. Waite ◽  
Amir Karton ◽  
Bun Chan ◽  
Alister J. Page
Keyword(s):  
Density Functional ◽  
Tight Binding ◽  
Binding Theory

Simulation of the Diffusion Features of Point Defects in bcc Metals

2006 ◽  
Vol 249 ◽  
pp. 41-46
Author(s):  
Andrey S. Chirkov ◽  
Andrei V. Nazarov
Keyword(s):  
Point Defects ◽  
Density Functional ◽  
Tight Binding ◽  
Interatomic Potentials ◽  
Binding Theory ◽  
Many Body ◽  
Functional Theory ◽  
Bcc Metals ◽  
Diffusion Characteristics ◽  
The Density Functional Theory

This work is devoted to simulation of the diffusion features of point defects in bcc metals. The properties of point defects have been investigated with the usage of many-body interatomic potentials. This approach, based on the density-functional theory, permitted us to derive more adequate diffusion features of solids. This investigation is carried out within the framework of the Finnis-Sinclair formalism, developed for an assembly of N atoms and represents the secondmoment approximation of the tight-binding theory. We used a new model, based on the molecular static method for simulating the atomic structure near the defect and vacancy migration in pure metals. This approach gives the opportunity to simulate the formation and the migration volumes of the point defects, taking into consideration the influence of pressure on structure and consequently on energy. The diffusion characteristics of bcc α-Fe and anomalous β-Zr have been investigated.

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