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azide_supcr.pdf (713.33 kB)

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

submitted on 11.09.2019, 22:56 and posted on 13.09.2019, 15:01 by Anwesa Karmakar

A series of ab initio MD simulations has been carried out for aqueous azide (N3-) 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.


Department of Science and Technology India

Laboratory Directed Research and Development program grant no. 20170046DR in Los Alamos National Laboratory, US.


Email Address of Submitting Author


JNCASR, Bangalore



ORCID For Submitting Author


Declaration of Conflict of Interest

No conflict of interest

Version Notes

First version