Classical molecular dynamics simulations of various mixtures of POPC:POPS lipid bilayers in water solution with only Na+ counterions (or with K+ counterions when noted with "_KCl" suffix). ECC-lipids force field parameters used for lipids, SPC/E water model and ECC-ions, all parameters available at https://github.com/jmelcr/ecc_lipids simulations performed with Gromacs 2018.0 (*.xtc files) simulation length 1000 ns = 1 microsecond temperature 298 K Gromacs simulation setting is in the file npt_lipid_bilayer.mdp