Effective particle size governs structure and dynamics in rough hard-particle fluids

Nanqing Xiao; Zhen Zhang; Walter Kob; Yujie Wang

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arXiv · 2609.08699

Effective particle size governs structure and dynamics in rough hard-particle fluids

Nanqing Xiao·Zhen Zhang·Walter Kob·Yujie Wang

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Abstract

We numerically investigate how particle surface roughness affects the static and dynamic properties of a hard-particle fluid across a wide range of densities, rho. These simulations of a simple model of granular systems reveal that, although the amplitude and coverage of surface corrugation significantly influence the rho-dependence of system properties, the qualitative behavior of this dependence remains unchanged. These findings can be described quantitatively by introducing an effective particle size, which enables a direct mapping of the rough particle systems to equivalent hard-disk systems. Analytical calculations provide an explicit form of this mapping, and allow us to predict the static and dynamic properties of rough particles using standard liquid-state theories for hard disks.

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Nanqing Xiao, Zhen Zhang, Walter Kob, Yujie Wang. 2026-09-08. Effective particle size governs structure and dynamics in rough hard-particle fluids. https://arxiv.org/abs/2609.08699

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