Dissociation Mechanism of Water Molecules on the PuO2(110) Surface: An Ab Initio Molecular Dynamics Study

2017 ◽  
Vol 122 (1) ◽  
pp. 371-376 ◽  
Author(s):  
Cui Zhang ◽  
Yu Yang ◽  
Ping Zhang
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Ab Initio Molecular Dynamics ◽  
Water Molecules ◽  
Dissociation Mechanism

AN AB INITIO MOLECULAR DYNAMICS STUDY ON THE SOLVATION OF FORMATE ION AND FORMIC ACID IN WATER

2012 ◽  
Vol 11 (05) ◽  
pp. 1019-1032 ◽  
Author(s):  
QIUBO CHEN ◽  
ZHIFENG LIU ◽  
CHEE HOW WONG
Keyword(s):  
Molecular Dynamics ◽  
Formic Acid ◽  
Ab Initio ◽  
Thermal Dissociation ◽  
Ab Initio Molecular Dynamics ◽  
Water Molecules ◽  
Hydrogen Bond Interaction ◽  
Acidic Dissociation ◽  
Partial Dissociation ◽  
Dynamics Simulations

Formate ion and formic acid are linked in water by the equilibrium for the acidic dissociation of formic acid, which as the simplest carboxylic acid is an important model system. In this study, the microscopic details of the solvation around a formate ion and around a formic acid molecule in aqueous solution are explored by ab initio molecular dynamics simulations, at 300, 500, 700, and 900 K. The formate ion exerts a strong influence on the surrounding solvent molecules by hydrogen bonding, which restricts the access of other water molecules. With rising temperature, the hydrogen bonds are disrupted, and the space around formic acid becomes more accessible. Solvation of the formic acid is marked by its partial dissociation to produce a proton, and the hydrogen bond interaction around a formic acid is not as strong as that around a formate ion. The acidic dissociation becomes less favorable as temperature rises, which indicates a lesser catalytic role for the water molecules in the thermal dissociation of formic acid.

An ab initio molecular dynamics study on hydrogen bonds between water molecules

2012 ◽  
Vol 136 (16) ◽  
pp. 164313 ◽  
Author(s):  
Zhang Pan ◽  
Jing Chen ◽  
Gang Lü ◽  
Yi-Zhao Geng ◽  
Hui Zhang ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bonds ◽  
Ab Initio ◽  
Ab Initio Molecular Dynamics ◽  
Water Molecules

scholarly journals Tetrahydrofuran (THF)-Mediated Structure of THF·(H2O)n=1–10: A Computational Study on the Formation of the THF Hydrate

Crystals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 73 ◽  
Author(s):  
Jinxiang Liu ◽  
Yujie Yan ◽  
Youguo Yan ◽  
Jun Zhang
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Computational Study ◽  
Ab Initio Molecular Dynamics ◽  
Water Molecules ◽  
Binding Ability ◽  
Hexagonal Ring ◽  
Weak Hydrogen Bonds ◽  
Dynamics Simulations ◽  
H2 Molecule

Tetrahydrofuran (THF) is well known as a former and a promoter of clathrate hydrates, but the molecular mechanism for the formation of these compounds is not yet well understood. We performed ab initio calculations and ab initio molecular dynamics simulations to investigate the formation, structure, and stability of THF·(H2O)n=1–10 and its significance to the formation of the THF hydrate. Weak hydrogen bonds were found between THF and water molecules, and THF could promote water molecules from the planar pentagonal or hexagonal ring. As a promoter, THF could increase the binding ability of the CH4, CO2, or H2 molecule onto a water face, but could also enhance the adsorption of other THF molecules, causing an enrichment effect.

Combustion Driven by Fragment-based Ab Initio Molecular Dynamics Simulation

2019 ◽  
Author(s):  
Liqun Cao ◽  
Jinzhe Zeng ◽  
Mingyuan Xu ◽  
Chih-Hao Chin ◽  
Tong Zhu ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Ab Initio ◽  
Large Scale ◽  
Methane Combustion ◽  
Combustion Method ◽  
Dynamics Simulation ◽  
Ab Initio Molecular Dynamics ◽  
Computational Time ◽  
Combustion Mechanism ◽  
Daily Lives

Combustion is a kind of important reaction that affects people's daily lives and the development of aerospace. Exploring the reaction mechanism contributes to the understanding of combustion and the more efficient use of fuels. Ab initio quantum mechanical (QM) calculation is precise but limited by its computational time for large-scale systems. In order to carry out reactive molecular dynamics (MD) simulation for combustion accurately and quickly, we develop the MFCC-combustion method in this study, which calculates the interaction between atoms using QM method at the level of MN15/6-31G(d). Each molecule in systems is treated as a fragment, and when the distance between any two atoms in different molecules is greater than 3.5 Å, a new fragment involved two molecules is produced in order to consider the two-body interaction. The deviations of MFCC-combustion from full system calculations are within a few kcal/mol, and the result clearly shows that the calculated energies of the different systems using MFCC-combustion are close to converging after the distance thresholds are larger than 3.5 Å for the two-body QM interactions. The methane combustion was studied with the MFCC-combustion method to explore the combustion mechanism of the methane-oxygen system.

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