Role of range of interaction potential on structure and dynamics of a one-component system of particles interacting via Mie potential

S Suvarna and M Priya, AIP ADVANCES, 14, 045030 (2024).

DOI: 10.1063/5.0199631

The thermodynamic and transport properties of a fluid depend significantly on the particle interactions at the molecular level. The range of these interparticle interactions thus plays a crucial role in determining its phase behavior. In the present work, we study the role of the range of particle-particle interaction potential on the structure and dynamics of a two-dimensional fluid in the proximity of the liquid- solid phase transition using molecular dynamics simulations. The particles are considered to interact via a Mie (2n, n) potential, and the range of this potential is varied by changing the attractive exponent n from 4 to 20. As the range of interaction potential is increased, a decrease in the local structural order is observed, while the sixfold orientational order remains almost invariant. Some exceptions are observed for the longest range of interaction potential at the liquid-solid phase transition temperature. Furthermore, we observe a temperature-dependent crossover in the relaxation of the nearest-neighbor correlations and the self-diffusion coefficient with a change in the interaction range. This results in a similar crossover in the Stokes-Einstein relation of the two-dimensional system of particles. In addition, we observe a deviation from the conventional Stokes- Einstein relation in systems interacting via these Mie potentials.

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