A protocol is described for the treatment of molecular polarization in force field calculations. The resulting model is consistent in that both inter- and intramolecular polarization are handled within a single scheme. An analytical formula for removing intramolecular polarization from a set of atomic multipoles for an arbitrary static structure or conformation is given. With the help of the in...

Ah&act-Normal coordinate analyses are presented for half-bilirnbin molecules. Calculations for the A-B pyrromethenone include intramolecular hydrogen bonds, while those for the C-D chromophore exclude intramolecular hydrogen bonds. Valence force-held parameters have been optimized to correlate closely with the IR and Raman spectra of the target molecules. The results of the calculations are com...

In traditional molecular mechanics force fields, intramolecular non-bonded interactions are modelled as intermolecular interactions, and the form of the torsion potential is based on the conformational profiles of small organic molecules. We investigate how a separate model for the intramolecular forces in pharmaceuticals could be more realistic by analysing the low barrier to rotation of the p...