[gmx-users] how to adjust the box size to correct density?

[Chang Woon Jang]

Dear Gromacs Users,


I have a low density polymer system initially. I would like to fit the
correct liquid density using NPT simulation.

I used Pcoupl=berendsen for 22 ns but the box size in confout.gro is still
the same as the input size of conf.gro.

Initial in conf.gro (10.0 10.0 9.8)
output in confout.gro (10.0 10.0 9.8)

My initial conditions are

tau_p=5.0
compressibility=4.5e-5
ref_p=1.0

Do I need to increase compressibility?

Thank you.

Best regards,
Changwoon Jang,