Recent advances in molecular simulations of clays: From slit pore to clay matrix nanopore.

Clays play a critical role in natural and engineered systems due to their unique layered structures, surface reactivity, and capacity to regulate fluid and solute behavior. From carbon sequestration and contaminant containment to enhanced oil recovery and subsurface energy storage, understanding clay-fluid interactions is essential for predicting system performance of sediment complex. However, most atomistic studies have relied on idealized infinite-sheet models, which overlook critical features such as edge terminations, finite particle size, and morphological heterogeneity-elements that dominate in real clay aggregates. This review addresses this knowledge gap by synthesizing recent advances in finite-particle modeling, which capture edge chemistry, stacking disorder, and confinement-driven transport dynamics. We examine the structural construction of finite clay models, discuss key force field developments, and highlight how finite systems alter hydration, ion adsorption, and molecular diffusion. Particular focus is placed on the emergence of anisotropic pore geometries, dynamic confinement effects, and size-dependent mechanical behavior. By bridging infinite and finite modeling paradigms, this review aspires to contribute to on-going efforts in modeling, experimentation, and multiscale integration toward more representative depictions of clay behavior across diverse applications.