1 Department of Chemistry and Biochemistry and Centre for Research in Molecular Modeling (CERMM), Concordia University , 7141 Sherbrooke Street West, Montréal, Québec H4B 1R6, Canada.

Cation-p interactions play important roles in the stabilization of protein structures and protein-ligand complexes. They contribute to the binding of quaternary ammonium ligands (mainly RNH(3)^(+) and RN(CH(3))(3)^(+)) to various protein receptors and are likely involved in the blockage of potassium channels by tetramethylammonium (TMA^(+)) and tetraethylammonium (TEA^(+)). Polarizable molecular models are calibrated for NH(4)^(+), TMA^(+), and TEA^(+) interacting with benzene, toluene,...