First principles molecular dynamics of molten NaCl

Area of Science:

• Computational chemistry and condensed matter physics.
• Materials science and physical chemistry.

Background:

• Classical molecular dynamics (MD) models often struggle to accurately represent the complex behavior of molten salts.
• The influence of induction forces on molten salt properties requires sophisticated modeling techniques.

Purpose of the Study:

• To investigate molten sodium chloride (NaCl) using first principles Hellmann-Feynman molecular dynamics (HFMD).
• To assess the impact of induction forces on the structural and dynamic properties of molten NaCl.
• To compare HFMD results with classical MD simulations using rigid-ion and shell-model potentials.

Main Methods:

• First principles Hellmann-Feynman molecular dynamics (HFMD) simulations.
• Calculation of partial radial distribution functions.
• Analysis of velocity and force autocorrelation functions.
• Comparison with classical MD simulations (rigid-ion and shell-model potentials).

Main Results:

• HFMD successfully reproduces experimentally observed structural features of molten NaCl.
• Classical MD potentials fail to accurately describe the molten salt structure.
• HFMD-derived Green-Kubo self-diffusion coefficients show better agreement with experimental data than classical MD.

Conclusions:

• First principles HFMD is a superior method for accurately simulating molten NaCl compared to classical MD.
• Induction forces play a crucial role in the accurate modeling of molten salt systems.
• The study provides a foundation for using ab initio parametrized polarizable interionic potentials in MD simulations.