Theoretical basis and accuracy of a non-iterative polarization protocol in molecular mechanics energy function calculations

The theory of dipole polarization as used in molecular mechanics energy functions is analyzed, and the difference in induction energy between an iterative (self-consistent) and non-iterative (one-step) scheme is derived. It is concluded that this difference is bound to be small in most cases, so that a non-iterative polarization model can be expected to give a satisfactory representation of the induction energy. This is demonstrated with examples of configurations of water molecules. The advantages of a one-step procedure are discussed.