Hydrogen Storage in MgH2 Matrices: An Ab-Initio Study of Mg-MgH2 Interface

2008 ◽  
Vol 139 ◽  
pp. 23-28 ◽  
Author(s):  
Simone Giusepponi ◽  
Massimo Celino ◽  
Fabrizio Cleri ◽  
Amelia Montone
Keyword(s):  
Molecular Dynamics ◽  
Total Energy ◽  
Ab Initio ◽  
Atomic Hydrogen ◽  
Level Structure ◽  
Atomic Level ◽  
Work Of Adhesion ◽  
Ab Initio Study ◽  
Dynamics Method ◽  
Good Agreement

We studied the atomic-level structure of a model Mg-MgH2 interface by means of the Car-Parrinello molecular dynamics method (CPMD). The interface was characterized in terms of total energy calculations, and an estimate of the work of adhesion was given, in good agreement with experimental results on similar systems. Furthermore, the interface was studied in a range of temperatures of interest for the desorption of hydrogen. We determined the diffusivity of atomic hydrogen as a function of the temperature, and give an estimate of the desorption temperature.

Effect of Chromium and Vanadium on Nanolayered Ternary Carbides: AB Initio Study

2009 ◽  
Vol 609 ◽  
pp. 239-242
Author(s):  
A.E. Merad ◽  
M.B. Kanoun
Keyword(s):  
Electronic Structure ◽  
Total Energy ◽  
Ab Initio ◽  
Structural Parameters ◽  
Ab Initio Study ◽  
Generalized Gradient ◽  
Generalized Gradient Approximation ◽  
Full Relaxation ◽  
Relaxation Procedure ◽  
Ternary Carbides

The Cr2AlC and V2AlC nanolayered ternary carbides are studied by performing APW-lo ab initio total energy calculations within the recent Wu-Cohen generalized gradient approximation GGA. Using full relaxation procedure of the volume and the atomic positions we obtained the structural parameters and electronic structure of the optimization hexagonal. Results were compared with the experimental ones. Interesting features are deduced. In fact, we have shown why these materials are conductors.

scholarly journals STRUCTURAL AND ELECTRONIC PROPERTIES OF BRIDGED BITHIOPHENE S-OXIDES (BTO) WITH S, S=O, O, SiH2 and BH2 BRIDGE: SEMI-EMPIRICAL AND AB INITIO STUDY

2010 ◽  
Vol 18 (18) ◽  
pp. 1-10
Author(s):  
Banjo Semire ◽  
Isaiah Ajibade Adejoro ◽  
Olusegun Ayobami Odunola
Keyword(s):  
Density Functional Theory ◽  
Thermodynamic Properties ◽  
Ab Initio ◽  
Density Functional ◽  
Ab Initio Study ◽  
Empirical Methods ◽  
Functional Theory ◽  
Structural And Electronic Properties ◽  
Semi Empirical ◽  
Good Agreement

In this paper, we theoretically studied the geometries, stabilities, electronic and thermodynamic properties of bridged bithiophene S-oxide (BTO-X) derivates (with X = BH2, SiH2, S, S=O, and O) by using semi-empirical methods, ab-initio, and Density functional theory. The geometries and thermodynamic parameters calculated by PM3 were in good agreement with that of B3LYP/6-31G(d). The bandgap calculated by B3LYP/6-31G(d) ranged from 3.94eV (BTO-O)-3.16eV (BTO-BH2). The absorption λmax calculated suing B3LYP/6-31G(d) shifted to longer wavelength with X=BH2, SiH2, and S=O due to enhancement of π-conjugated system whereas, BTO-S and BTO-O shifted to shorter wavelengths as compared to dimmer thiophene S-oxide (2TO).

scholarly journals Exploring Dynamics and Structure of Biomolecules, Cryoprotectants, and Water Using Molecular Dynamics Simulations: Implications for Biostabilization and Biopreservation

2019 ◽  
Vol 21 (1) ◽  
pp. 1-31 ◽  
Author(s):  
Lindong Weng ◽  
Shannon L. Stott ◽  
Mehmet Toner
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulations ◽  
Molecular Motion ◽  
State Of The Art ◽  
Level Structure ◽  
Cost Effective ◽  
Atomic Level ◽  
Computational Research ◽  
Dynamics Simulations ◽  
Biological Entities

Successful stabilization and preservation of biological materials often utilize low temperatures and dehydration to arrest molecular motion. Cryoprotectants are routinely employed to help the biological entities survive the physicochemical and mechanical stresses induced by cold or dryness. Molecular interactions between biomolecules, cryoprotectants, and water fundamentally determine the outcomes of preservation. The optimization of assays using the empirical approach is often limited in structural and temporal resolution, whereas classical molecular dynamics simulations can provide a cost-effective glimpse into the atomic-level structure and interaction of individual molecules that dictate macroscopic behavior. Computational research on biomolecules, cryoprotectants, and water has provided invaluable insights into the development of new cryoprotectants and the optimization of preservation methods. We describe the rapidly evolving state of the art of molecular simulations of these complex systems, summarize the molecular-scale protective and stabilizing mechanisms, and discuss the challenges that motivate continued innovation in this field.

Electronic and optical properties of K-doped ZnO: Ab initio study

2016 ◽  
Vol 30 (23) ◽  
pp. 1650291 ◽  
Author(s):  
D. E. Aimouch ◽  
S. Meskine ◽  
R. Hayn ◽  
A. Zaoui ◽  
A. Boukortt
Keyword(s):  
Ab Initio ◽  
Density Functional ◽  
Complete Analysis ◽  
Local Spin Density Approximation ◽  
Ab Initio Study ◽  
Functional Theory ◽  
Text Type ◽  
Doped Zno ◽  
Optical Applications ◽  
Good Agreement

We present the results of ab initio calculations of K-doped ZnO in the wurtzite structure using a supercell of 32 atoms and density functional theory. A complete analysis of its electronic, optical and magnetic properties is provided. The local spin density approximation (LSDA) has been used to analyze the density of states and to understand the K influence at different concentration values. The material is revealed to become a [Formula: see text]-type doped semiconductor. The optical constant or refractive index, the dielectric function, and the absorption coefficient were determined and show a good agreement with available experimental data. Potassium doping leads to an absorption peak at about 380 nm. That peak might improve the absorption characteristics of ZnO for solar cell or optical applications.

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