Dear Users, I'm determining my .mdp file for NPT equilibration, but I don't know how to determine the ref_p section of mdp. pcoupl = berendsen pcoupltype = surface-tension tau_p = 0.5 0.5 ref_p = 1.0 1.0 compressibility = 4.46e-5 4.46e-5 I'm gonna to calculate surface tension for a layer of water. Sincerely, Iman