CMSP Webinar (Atomistic Simulation Seminar Series) 17 April, 11:00hrs, by Dr Avula

[CMSP Seminars Secretariat]

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CMSP Webinar (Atomistic Simulation Seminar Series)
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*Wednesday, 17 April 2024, 11:00 hrs (CET)*
/Zoom registration link: 
https://zoom.us/meeting/register/tJcqduyopjkrE9He-usl-16oLlY5Iz1Vl7W0<https://zoom.us/meeting/register/tJMpf-CorT0pEtWnaPyfrbX1otmigXiPSxqv>
<https://zoom.us/meeting/register/tJcqduyopjkrE9He-usl-16oLlY5Iz1Vl7W0> /

Speaker:*  Nikhil V S Avula * (Jawaharlal Nehru Centre for Advanced 
Scientific Research, India)

Title: *Machine Learned Potentials to Understand Specific Ion Effects in 
Aqueous Electrolytes*

Abstract:
Modeling aqueous electrolytes has been challenging, despite the 
tremendous progress in the field. One phenomenon that is particularly 
difficult to capture is the “anomalous diffusion” of water in salt 
solutions. The diffusivity of water in aqueous cesium iodide solutions 
is larger than that in neat liquid water and vice versa for sodium 
chloride solutions. Such peculiar ion-specific behavior, called 
anomalous diffusion, is not reproduced in typical force field based 
molecular dynamics (MD) simulations due to inadequate treatment of 
ion-water interactions. In this talk, I shall demonstrate that machine 
learned atomic potentials (MLPs) trained on quantum density functional 
theory (DFT) data can reproduce the experimentally determined 
thermodynamic, structural, dynamical, and transport properties, 
including their varied trends in water diffusivities across salt 
concentration. Further, MLPs reveal that - while both ions in CsI 
solutions contribute to the faster diffusion of water molecules, the 
competition between the heavy retardation by Na ions and the slight 
acceleration by Cl ions in NaCl solutions reduces their water 
diffusivity. In the end, I shall briefly discuss our recent attempts to 
develop a universal MLP that can model all alkali-halide aqueous 
solutions at DFT accuracy.

References:

1.     Nikhil V. S. Avula, Michael L. Klein, and Sundaram 
Balasubramanian, J. Phys. Chem. Lett. 2023, 14, 9500–9507


http://www.ictp.it/research/cmsp.aspx

The Abdus Salam International Centre for Theoretical Physics
https://www.ictp.it/

    
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