Effective simulation methods for polyelectrolytes in low dielectric solvents


  • M. O. Khan
  • G. Kennedy
  • D. Y. C. Chan




Simulations of polyelectrolytes in low dielectric solvents converge slowly. This can be circumvented by using clothed global moves or parallel expanded techniques. In clothed moves the counterions are moved with the polyelectrolyte backbone and are not left behind when a substantial part of the chain is moved. For moderately charged systems the speed-up has been shown to be by a factor of up to 3. We show how, for systems with strong electrostatic interactions, much larger efficiency gains in the simulation process, by a factor of over 400, can be obtained. In our parallel expanded algorithm, a number of conventional Monte--Carlo simulations are carried out in parallel, with only the dielectric constant being different. By allowing the different simulations to communicate and exchange conformations, trapped configurations in the low dielectric simulations may escape via the higher dielectric simulations. We show how this method scales linearly up to 8 processors for highly charged polyelectrolytes.





Proceedings Computational Techniques and Applications Conference