ON THE TREATMENT OF ELECTROSTATIC INTERACTIONS IN BIOMOLECULAR SIMULATION

An extended electrostatics model that combines a standard pairwise additive scheme for spatially close interactions with a multipole approximation for the calculation of spatially distant interactions is described. Energy calculations and vacuum dynamics simulations of bovine pancreatic trypsin inhibitor (BPTI) are employed in an evaluation of the model. The results obtained indicate that the extended electrostatics model can minimize cutoff effects in molecular dynamics simulation of biomolecules. While an additional computational overhead exists in the use of this model, the cost is significantly less than that of longer cutoffs which give corresponding results.