In addition to experimental approaches, molecular simulations have been used to analyze interface structures and dynamic behaviors, such as ionic conduction. Common simulation techniques include classical molecular dynamics (CMD) and ab initio molecular dynamics (AIMD) based on density functional theory (DFT), which provide structural and dynamical information about interfacial regions at the atomic level. Although AIMD is a powerful tool for atomic-scale analysis, its high computational cost limits the system size for materials with interfaces. CMD, when using well-verified potential parameters, can handle large-scale calculations involving tens of thousands of atoms, making it suitable for studying complex atomic systems such as crystal-glass interfaces. These simulation approaches offer significant advantages in analyzing time-dependent crystalline growth at interfaces, which is difficult to observe experimentally because of limitations in spatial and temporal resolution. To investigate crystal growth phenomena, this study focused on typical sulfide glassceramics composed of β-Li 3 PS 4 and 75Li 2 S-25P 2 S 5 glass. Sulfide-based glass-ceramics are promising materials for solid-state electrolytes in all-solid-state batteries. Many types of sulfide glass-ceramics have been reported as solid-state electrolytes. Material composed of β-Li 3 PS 4 and 75Li 2 S-25P 2 S 5 glass is an ideal model for investigating interfaces in glass-ceramics because both glassy and crystalline phases share the same atomic composition, with ordered and disordered alignments of PS 4 3 -. In addition, Li + exhibits significant mobility due to the high flexibility of the host PS 4 3structure, as shown by AIMD and