Abstract <p>Dynamic structures of the solid–liquid interface (SLI) during solidification along the (100) and (110) orientations of Ni and Al were investigated using molecular dynamics simulations. Non-equilibrium solidification results show that although the global system temperature reaches equilibrium, a pronounced temperature gradient exists near the interface. This phenomenon arises mainly from two factors: the Nose’–Hoover thermostat regulates atomic velocities based on global temperature without accounting for local variations, and classical molecular dynamics neglects electronic contributions to thermal conduction. Structural density analysis reveals that the density near the crystal–liquid interface exhibits ordered oscillations within the transition layer. The interfacial concentration deficit is negligible at small undercoolings and increases gradually with increasing undercooling, which correlates with the temperature-dependent interface growth rate. Two-dimensional structure factor and atomic configuration analyses demonstrate that the crystal-to-liquid transition proceeds from long-range order to short-range order via a gradual decay of structural ordering. A small number of vacancy defects appear in the crystalline layers, and no significant orientational anisotropy is observed between the (100) and (110) interfaces.</p>