In the second phase, the AL was initiated using one of the clusters generated during the previous phase, with the radius reduced by placing the harmonic bias at a distance of 7.5 Å to increase the density of the solvent around Mg 2+ and enhance the sampling of the repulsive region of the potential. To avoid selecting overly distorted structures resulting from potentially unstable dynamics, the selector threshold was tightened to 0.9999. Simultaneously, the AL time was increased to 20 ps to further capture longer water dynamics. The second phase resulted in generating an additional 55 structures.