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

Melting of Hydrogen Bonds in Uracil Derivatives Probed by Infrared Spectroscopy and ab Initio Molecular Dynamics

2012 ◽  
Vol 116 (15) ◽  
pp. 4626-4633 ◽  
Author(s):  
Zsolt Szekrényes ◽  
Katalin Kamarás ◽  
György Tarczay ◽  
Anna Llanes-Pallás ◽  
Tomas Marangoni ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Infrared Spectroscopy ◽  
Hydrogen Bonds ◽  
Ab Initio ◽  
Ab Initio Molecular Dynamics ◽  
Uracil Derivatives

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.

Resolving the anomalous infrared spectrum of the MeCN–HCl molecular cluster using ab Initio molecular dynamics

2014 ◽  
Vol 16 (45) ◽  
pp. 24685-24690 ◽  
Author(s):  
Nicolai Bork ◽  
Ville Loukonen ◽  
Henrik G. Kjaergaard ◽  
Hanna Vehkamäki
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bonds ◽  
Infrared Spectrum ◽  
Ir Spectra ◽  
Ab Initio ◽  
Molecular Dynamics Simulations ◽  
Molecular Complexes ◽  
Ab Initio Molecular Dynamics ◽  
Molecular Cluster ◽  
Dynamics Simulations

Molecular dynamics simulations reveal that the asymmetric peak seen in IR spectra of acetonitrile–HCl molecular complexes are due to high population of complexes with partially broken hydrogen bonds.

scholarly journals Combined ReaxFF and Ab Initio MD Simulations of Brown Coal Oxidation and Coal–Water Interactions

Entropy ◽  
2021 ◽  
Vol 24 (1) ◽  
pp. 71
Author(s):  
Shi Yu ◽  
Ruizhi Chu ◽  
Xiao Li ◽  
Guoguang Wu ◽  
Xianliang Meng
Keyword(s):  
Molecular Dynamics ◽  
Hydrogen Bonds ◽  
Ab Initio ◽  
Brown Coal ◽  
Water Adsorption ◽  
Md Simulations ◽  
Dynamics Simulation ◽  
Ab Initio Molecular Dynamics ◽  
Coal Oxidation ◽  
Simulation Results

In this manuscript, we use a combination of Car–Parrinello molecular dynamics (CPMD) and ReaxFF reactive molecular dynamics (ReaxFF-MD) simulations to study the brown coal–water interactions and coal oxidation. Our Car–Parrinello molecular dynamics simulation results reveal that hydrogen bonds dominate the water adsorption process, and oxygen-containing functional groups such as carboxyl play an important role in the interaction between brown coal and water. The discrepancy in hydrogen bonds formation between our simulation results by ab initio molecular dynamics (CPMD) and that by ReaxFF-MD indicates that the ReaxFF force field is not capable of accurately describing the diffusive behaviors of water on lignite at low temperatures. The oxidations of brown coal for both fuel rich and fuel lean conditions at various temperatures were investigated using ReaxFF-MD simulations through which the generation rates of major products were obtained. In addition, it was observed that the density decrease significantly enhances the generation of gaseous products due to the entropy gain by reducing system density. Although the ReaxFF-MD simulation of complete coal combustion process is limited to high temperatures, the combined CPMD and ReaxFF-MD simulations allow us to examine the correlation between water adsorption on brown coal and the initial stage of coal oxidation.

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