Re: [gmx-users] Including quadrupole-charge interaction in GROMACS

Hi, For neutral species, I think it's straightforward (unless the paper Ran Friedman mentioned says otherwise). Just use the definition of the quadrupole moment to figure out where to put the charges and what magnitude to assign to them. The electric field from a quadrupole declines like r^-3,

Re: [gmx-users] Including quadrupole-charge interaction in GROMACS

Hi, Erik, Thanks for the information. Regarding using more than two partial charges to mimic quadrupole explicitly, is there a one-to-one relation between the quadrupole moments and "position and magnitude" of the partial charges? For example, if I would like to include quadrupole moment for carb

Re: [gmx-users] Including quadrupole-charge interaction in GROMACS

Quadrupole interactions are implicit whenever you have a molecule withe more than two partial charges. You don't have to include it explicitly. There are, however, multipole expansion techniques to speed up electrostatics calculations, but that's another story. Erik 15 jun 2011 kl. 23.45 skrev

[gmx-users] Including quadrupole-charge interaction in GROMACS

Dear GMXers, Is there a way in GROMACS to include quadrupole-charge interaction? Or is there a standard to way to mimic quadrupole moment using partial charge? Thank you. Best, Yanbin -- gmx-users mailing listgmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users Please s