Isothermal compressibility

GROMACS version: 2018
GROMACS modification: Yes/No
Dear Prof. Lemkul,
I’m simulating 4000 toluene in a box of simulation. Is it necessary to set the compressibility of toluene in the npt.mdp file or the compressibility of water is satisfying?
Thank you

I have no idea how different the value is or if it might change the simulation results, but for a simple system like this, the value must be known so why wouldn’t you use the real compressibility?