Atomic partial charges for the fluorinated methane derivatives were obtained with the Merz-Singh-Kollman Restrained Electrostatic Potential (RESP) methodology on a single conformation for each molecule, following the standard GAFF protocol. The charges were calculated at the RHF/6-31G* level of theory from a two-step geometry optimization (MP2/6-31G* optimization followed by RHF/6-31G* optimization). Quantum mechanical calculations were performed with the Gaussian 03 software , and RESP fitting of the partial charges was performed with the Antechamber package .