[lammps-users] About Coulomb interactions

Dear LAMMPS users,

I am wondering whether LAMMPS can have a full calculation of Coulomb interactions with Ewald or PPPM in reciprocal space. I checked with the manual. It seems we have to assign a nonzero cutoff for direct Coulomb interactions calculation and reciprocal space calculation is only used for the region beyond this cutoff. I don’t want this separated calculation.

Any help would be most appreciated.

Yajie Lei

Not sure why you would want this, since the sum
of the real space and the reciprocal space is the
full Coulomb energy. But if you set the cutoff
smaller than the nearest neighbor distance (but
still > 0), I guess you would get no real-space
pairs and everything in reciprocal space.