The AMOEBA polarizable force field uses atomic multipole moment through quadrupoles and induced dipole polarization to provide electrostatic potentials accurate to 0.1 to 0.01%, compared to 1% to 10% errors for simple partial charge only models.
High-order atomic multipoles provide anisotropy critical to accurate description of hydrogen bonding. For example, isotropic models overestimate the strength of linear vs. bent hydrogen bonds at carbonyls by about 1.5 kcal/mol.
Polarization effects are very important for modelling of simple ions, metals and highly charged species like nucleic acids and membrane head groups. For example, roughly half the attraction in π-cation interactions is due to polarization, and this can amount to several kcal/mol.
Inclusion of water polarization is mandatory to model the thermodynamics of desolvation. Traditional fixed charge bulk water models such as TIP3P and TIP4P do not respond to presence in protein binding pockets, leading to significant errors in predicted absolute ligand binding free energies.