When focussing on the 7 ligand pairs with σ T IES larger for REST2 predictions, another interesting trend is observed. 3 of the 7 have σ T IES increased by ≤ 0.01 kcal/mol which is insignificant and may be ignored. The remaining 4 belong to the BACE (scaffold) system which has all positively charged alchemical regions. As discussed earlier, charged groups in the alchemical region lead to large uncertainities and less accurate results with the standard TIES protocol due to attenuation of the electrostatic interactions possibly leading to more frequent sampling of higher energy conformations. This phenomenon is enhanced with REST2 due to further weakening of electrostatic interactions in the intermediate λ states.