If the hydrogel is compressed in the ẑ-direction (i.e., λ < 0), the condensation around the chains aligned in the ẑ-direction does not change for the maximum compression, λ ≈ -0.2, that we achieve (see Figure ). However, the condensation levels in the x and ŷ directions increase with increasing compression (see Figure ). Note that as the hydrogel is compressed at λ < 0, the chains aligned in the x and ŷ directions are stretched. This conformational change is accompanied by an increase in the counterion condensation. This situation is similar to the λ > 0 cases, for which the chains aligned in the ẑ-direction are stretched. The representative snapshots shown in Figure . 2d, in which condensed and free counterions are indicated by green and purple colors, respectively, are consistent with the condensation patterns in Figure . 2b; while there are visually more condensed counterions near the chains aligned in the ẑ direction at λ ≈ 0.2 (see Figure ), there are fewer ions localized near the chains aligned in the ẑ direction at λ ≈ -0.2. Overall, these compression and stretching simulations also suggest that condensation increases for the stretched chains of the hydrogel. However, over-stretching of the chains reduces the number of condensed ions.