A first principles theoretical study of vibrational spectral diffusion and hydrogen bond dynamics in aqueous ionic solutions: D2O in hydration shells of Cl− ions

2008 ◽  
Vol 129 (19) ◽  
pp. 194512 ◽  
Author(s):  
Bhabani S. Mallik ◽  
A. Semparithi ◽  
Amalendu Chandra
Keyword(s):  
Hydrogen Bond ◽  
First Principles ◽  
Theoretical Study ◽  
Spectral Diffusion ◽  
Ionic Solutions ◽  
Hydration Shells ◽  
Hydrogen Bond Dynamics ◽  
Aqueous Ionic Solutions

A first-principles theoretical study of hydrogen-bond dynamics and vibrational spectral diffusion in aqueous ionic solution: Water in the hydration shell of a fluoride ion

2012 ◽  
Vol 85 (1) ◽  
pp. 27-40 ◽  
Author(s):  
Jyoti Roy Choudhuri ◽  
Vivek K. Yadav ◽  
Anwesa Karmakar ◽  
Bhabani S. Mallik ◽  
Amalendu Chandra
Keyword(s):  
Hydrogen Bond ◽  
First Principles ◽  
Hydration Shell ◽  
Spectral Diffusion ◽  
Fluoride Ion ◽  
Water Molecules ◽  
Deuterated Water ◽  
Anion Hydration ◽  
Hydrogen Bond Dynamics ◽  
Water Hydrogen

We present a first-principles simulation study of vibrational spectral diffusion and hydrogen-bond dynamics in solution of a fluoride ion in deuterated water. The present calculations are based on ab initio molecular dynamics simulation for trajectory generation and wavelet analysis for calculations of frequency fluctuations. The O–D bonds of deuterated water in the anion hydration shell are found to have lower stretching frequency than the bulk water. The dynamical calculations of vibrational spectral diffusion for hydration shell water molecules reveal three time scales: a short-time relaxation (~100 fs) corresponding to the dynamics of intact ion-water hydrogen bonds, a slower relaxation (~7.5 ps) corresponding to the lifetimes of fluoride ion-water hydrogen bonds, and an even longer time scale (~26 ps) associated with the escape dynamics of water from the anion hydration shell. However, the slowest time scale is not observed when the vibrational spectral diffusion is calculated over O–D bonds of all water molecules, including those in the bulk.

A first principles simulation study of vibrational spectral diffusion in aqueous NaBr solutions: Dynamics of water in ion hydration shells

2013 ◽  
Vol 412 ◽  
pp. 13-21 ◽  
Author(s):  
Anwesa Karmakar ◽  
Jyoti Roy Choudhuri ◽  
Vivek K. Yadav ◽  
Bhabani S. Mallik ◽  
Amalendu Chandra
Keyword(s):  
Simulation Study ◽  
First Principles ◽  
Spectral Diffusion ◽  
Ion Hydration ◽  
Hydration Shells

scholarly journals Water in Hydration Shell of an Azide Ion: Structure and Dynamics of Solute-water Hydrogen Bonds and Vibrational Spectral Diffusion from First Principles Simulations At Supercritical Condition

2019 ◽  
Author(s):  
Anwesa Karmakar
Keyword(s):  
Hydrogen Bond ◽  
Hydration Shell ◽  
Solvation Shell ◽  
Spectral Diffusion ◽  
Supercritical Condition ◽  
Time Dependent ◽  
Dynamics Simulation ◽  
Azide Ion ◽  
Hydrogen Bond Dynamics ◽  
Water Hydrogen

<p>A series of ab initio MD simulations has been carried out for aqueous azide (N<sub>3</sub><sup>-</sup>) ion solutions at three different densities and at supercritical condition (673 K) using Car-Parrinello molecular dynamics simulation. The time dependent trajectories at three different densities have been used to analyze the hydrogen bond dynamics, residence dynamics, dangling OD bond dynamics and spectral diffusion and underlying connections between them. The time dependent frequency of both the OD and NN stretching mode has been calculated using the time series analysis of the wavelet method. The population correlation function approach has been used to compute the hydrogen bond dynamics, dangling OD bond and residence dynamics of the Sc-water both inside and outside the solvation shell of the ion. The faster hydrogen bond dynamics has been observed in the vicinity of the azide ion, however the calculated OD stretching frequency is found to show red shift in the vicinity of the azide ion indicative to the formation of stronger ion-water hydrogen bond even at the supercritical condition. The overall hydrogen bond dynamics at the supercritical condition was faster with respect to the aqueous azide ion solutions at the ambient condition.</p>

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