In general, molecules are stabilized by polarization in aggregated systems. Surprisingly, compared to the water molecules in pure water, the water molecules near the CH 3 -group of TMAO and TBA were found to have a decreased dipole moment (by 1% and 3%, respectively; Table ). This is because the steric barrier of the CH 3 -group allows only a small number of water molecules to be coordinated around the waters with decreased dipole moments. The ensemble averages of the dipole moments indicate that the influence of the solute on water converges around 4.5 Å (Figure and Table ).