I generated a box with protein, membrane and counterions using Ewald.
All my system is neutral, but now I want to do decomposition of energy from different parts of my system. I want to compute electrostatic energy and forces between any two selections which are not neutral using INTERACTION command.
I found that electrostatic forces are not correct. Do you know how to calculate the electrostatic energy between two selections if they are not neutral using EWALD without using cutt_off.