Hi Amit, So if I understand you correctly, any LJ interaction I impose on these particles will be quite arbitrary because I'm only concerned with electrostatics, right? How then might I go about comparing the dimensionless reference values given with the values I calculated? I don't think I can simply compare their ratios, as there would still be a unit of length to deal with.
Thanks, Alex On Fri, Jul 29, 2011 at 2:24 PM, Amit Choubey <[email protected]> wrote: > Hi, > > reduced units works for LJ particles only. I am not sure if it works when > you include electrostatics. When you set charge = 1 it is 1electronic > charge. I would suggest not to use the reduced units for LJ in this > scenario. > > Amit > > On Fri, Jul 29, 2011 at 8:05 AM, Alex Marshall <[email protected]> wrote: > >> Hi all, >> >> I'm trying to calculate the force on one particle and the total >> electrostatic energy of my system, which consists of a lattice of 25 evenly >> spaced charges in the xy plane and a single charge in the center above to >> preserve charge neutrality. The reference values I have been given are in >> dimensionless units, so I am tasked with either converting my output to >> dimensionless units or having gromacs work in reduced units from the get go. >> I have set the mass of each charge to 1, the magnitude of the charge on each >> particle to 1, and the values of the C6 and C12 parameters in my itp file to >> 4.0, since I'm just using gmx.ff for this (hopefully simple) calculation. >> I've turned off temperature coupling because this is purely a test of the >> handling of electrostatics with 3D Ewald summation plus the correction for >> slab geometry. However, the force and energy I calculate are still quite far >> from the reference values. Have I missed anything if I want my output to be >> in dimensionless units? >> >> Thanks, >> Alex >> >> -- >> gmx-users mailing list [email protected] >> 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 [email protected]. >> Can't post? Read http://www.gromacs.org/Support/Mailing_Lists >> > > > -- > gmx-users mailing list [email protected] > 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 [email protected]. > Can't post? Read http://www.gromacs.org/Support/Mailing_Lists >
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