The key difference between these mechanisms is the formation of a solvent-separated ion pair (SSIP) in the S N 1 pathway, favouring the α-product (Fig. ). In contrast, the S N i mechanism maintains the contact ion pair, providing access solely to the β-product, similar to the S N 2 pathway. Experimental data suggest that the mechanisms vary with temperature, as reflected by the temperature-dependent ratio of the α and β-product formation. To investigate how the mechanism changes with temperature, 100 MLIP-MD simulations were conducted at 223 K, 263 K, and 303 K, respectively (Fig. ). These simulations were initiated from the contact ion pair, Inter2, extracted from WTMetaD trajectories in explicit DCM and propagated for 40 ps without any bias. We monitored the formation of the SSIP, defined by the distances r C 1 -O LG > 7 Å and r C 1 -O Nu > 2.6 Å, where the LG is already far enough from the sugar to allow the insertion of the DCM solvent molecule, but the incoming Nu is further than the r C 1 -O Nu bond distance in TS3, ensuring that the ion pair can separate while β-product has not been formed yet. As anticipated, with increasing temperature, the prevalence of the contact ion pair decreased, leading to an increase in the percentage of SSIP from 14% at 223 K to 36% at 303 K. This trend confirms the decreasing stability of the contact ion pairs in DCM as temperature increases, which agrees with experimentally observed trend of ratios of α and β-product. It is important to emphasise that we reached our conclusions without making any preliminary assumptions about the reaction mechanism. The computational efficiency of our approach, compared to AIMD simulations, can be illustrated by examining the simulation times. For example, three independent 300-ps WTMetaD simulations for this system (284 heavy atoms in total) using linear ACE potential took approximately six days using 24 CPUs.