All-atom (AA) molecular dynamics (MD) simulations were used to study a bulk polyethylene glycol-water (PEG-H 2 O) system with a large range of PEG concentrations c PEG ∈ [0.01, 100] (Fig. ), where c PEG is unitless and defined as the ratio between the total number of PEG's oxygen atoms and the total number of H 2 O molecules. A PEG concentration c PEG = 0.01 corresponds to 2 PEG molecules and 1000 water molecules, and c PEG = 100 corresponds to 160 PEG molecules and 8 water molecules. AA MD simulations were performed with the open-source GROMACS simulation package . The number of atoms in each simulation was chosen approximately equal to 5000, corresponding to a typical box size of (3.4 nm) 3 . For most of the calculations, PEG200 with molar mass equal to 200 g/mol was used. PEG200 is composed of 3 monomer units, O(CH 2 ) 2 , and two ends, CH 2 OH, for a total of 5 oxygen atoms per PEG molecule (Fig ). Simulations with PEG molecules with molar mass ranging from M = 100 g/mol (3 monomers) to 600 g/mol (10 monomers) were also performed. The CSVR thermostat was used with a time constant of 0.5 ps to impose a temperature T = 298.15 K. An isotropic pressure coupling was applied using the Berendsen barostat with a time constant of 1 ps. A cutoff of 1.4 nm was used for the Lennard-Jones interaction with long range dispersion correction. Long range electrostatic interactions were handled using the smooth particle mesh Ewald method (SPME) . The TIP4P/ϵ force field was used for water together with the CHARMM36 force field for the PEG molecules . The simulation scripts are available on the DaRUS repository .