Dr. van der Spoel, Thank you for your time! So it seems that epsilon_r is just a "fudge factor" and has nothing to do with the dielectric constant at the boundary of the "PME/Ewald sphere." Is that dielectric constant actually epsilon_surface? I am not very familiar at all with other MD codes, but a colleague recently told me that some other codes use a default dielectric constant of infinity at the surface. However, in Gromacs, the default value of epsilon_surface is 0, which corresponds (I guess) to "no dielectric" at the surface. Is this true?
Also, to complicate things further, I am using a pseudo 2-D PME summation (ewald_geometry = 3dc). I have read in the manual entry for epsilon_surface that epsilon_surface "does not affect the slab 3DC variant of the long range corrections." If you have time, what does this mean? Does this mean that, if I use ewald_geometry = 3dc, then there is "no dielectric" at the surface (the medium surrounding the "Ewald sphere")? Thank you! Andrew DeYoung Carnegie Mellon University > epsilon_r should never be used with a regular force field because the > balance between coulomb and other terms will be wrong. maybe we should > remove the term. -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
