I am working on lipid bilayer and used water as a solvent. During npt space is formed at the water and bilayer interface. I had performed 4 steps of npt for 1ns, in the 3rd step there was the starting of space forming and in the 4th step clearly observed space. There was no error in npt equilibrium. I am curious about this space, why it is forming?. And also there was no error in the final simulation, but I'm not getting the result. Please can anyone help me?
I'm attaching the vmd view of the npt.trr and npt.gro file.