All DFT 29 calculations in this study were performed using the pseudopotential plane-wave DFT module (NWPW) implemented in the NWChem and NWChemEx 36,37 chemistry program package. The web application EMSL Arrows 38 was used to set up and perform the plane-wave calculations. The DFT PBE96 39 exchange correlation function was used for solvation energy calculations, and both PBE96 and the hybrid 29 PBE0 40 (75% PBE exchange + 25% exact exchange + 100% PBE correlation) exchange correlation functionals were applied to account for the exchange correlation energy in the SN2 reaction profile.