[gmx-users] a problem about ewald geometry=3dc

[Ali Shomali]

Hello to all Dear Gromacs Users

I'm modeling a lipid monolayer with vacuum space on top of it and with
periodic boundary conditions in xyz directions. the vacuum space is about
10nm to minimize any possible effect of periodicity. for using ewald
summation as manual mentions :

*"The geometry to use for Ewald summations. 3d means the sum is performed
in all three dimensions. If your system has a slab geometry in the x-y
plane you can try to increase box z dimension and use the 3dc geometry. The
reciprocal sum is still performed in 3d, but a force and potential
correction applied in the z dimension to produce a pseudo-2d summation. In
the future there might also be a true2d option, but this is not working y"*


however it causes warning :

 With PME and ewald_geometry = 3dc you should use pbc = xy

since I can't use pbc=xy , can I use 3dc with pbc in xyz and ignore the
warning ? how this affect results?

Thanks for your time and attention