Rajib Biswas
Articles written in Journal of Chemical Sciences
Volume 127 Issue 10 October 2015 pp 1715-1728
Sarmistha Sarkar Rajib Biswas Partha Pratim Ray Biman Bagchi
Using polydispersity index as an additional order parameter we investigate freezing/melting transition of Lennard-Jones polydisperse systems (with Gaussian polydispersity in size), especially to gain insight into the origin of the terminal polydispersity. The average inherent structure (IS) energy and root mean square displacement (RMSD) of the solid before melting both exhibit quite similar polydispersity dependence including a discontinuity at solid-liquid transition point. Lindemann ratio, obtained from RMSD, is found to be dependent on temperature. At a given number density, there exists a value of polydispersity index (𝛿P) above which no crystalline solid is stable.
Volume 129 Issue 7 July 2017 pp 1045-1051 REGULAR ARTICLE
Role of solvation structure in the shuttling of the hydrated excess proton
The classic Marcus electron transfer reaction model demonstrated that a barrierless electron transfer reaction can occur when both the reactant and product have almost similar solvation environment. In our recently developed proton model, we have incorporated the pre-solvation concept and showed that it indeed facilitates the proton diffusion in aqueous solution. In this work, we further quantify the degree of pre-solvation using different structural parameters, e.g., tetrahedral order parameter, average numbers of hydrogen bonds. All theabove said parameters exhibit a very strong correlation with the proton share parameter. The more Zundel-like configurations have almost identical solvation environment for both the water molecules and support the presolvationconcept. However, in the case of Eigen-like configurations, the central hydronium and “special pair” water have distinctly different solvation structures.
Volume 135 All articles Published: 12 January 2023 Article ID 0005
Hydrophobic Hydration: A Theoretical Investigation of Structure and Dynamics
KAMBHAM DEVENDRA REDDY RAJIB BISWAS
The presence of external solutes alters the local structures, and dynamics of water. The nature andextent of these structural modifications depend on several factors. Particularly, the chemical nature of the solute is very crucial. The alteration of water structure and dynamics in the presence of hydrophobic substances draws considerable attention in biological systems. The present work is focused on exploring the microscopic arrangement of solvation shells of tiny hydrophobic solute methane. We explore the tetrahedral order, local structural index, and van Hove self-correlation function to get a quantitative understanding. Weobserve a slight increase in the structural order of water molecules in methane’s first solvation shell, similar tothat of the low-temperature water. We also find that water facing the methane have lower structural order than bulk water. Furthermore, the water molecules in the first solvation shell around methane show relatively slower orientational relaxation.
The hydrophobicity-induced alterations of water structural and dynamical properties are investigated using solvation shell decomposition. We observe the slower relaxation of selected water molecules staying longer time in methane first solvation shell. We find enhanced structural order in the methane first solvation shell and some dangling water molecules.
Volume 135, 2023
All articles
Continuous Article Publishing mode
Click here for Editorial Note on CAP Mode
© 2023-2024 Indian Academy of Sciences, Bengaluru.