2D periodicity in lammps

Hello Everyone

i am going to calculate the potential energy for 2D water film with tip4p
water model.
when i am doing it in lammps, i am getting error that u cant use PPPM
method for 2D simulatuion.
so can u people suggest some other method to solve this problem.

thank you.

to handle long-range coulomb in a 2-dimensional system, you would need to program a 2d ewald summation or similar.

but are you certain, that you want to do a real 2d system (all z-coordinates are the same) and not a 3d system, that is periodic in 2 directions and non-periodic in the third?