[gmx-users] Can I set the dielectric constant for polymer and water separately

[zifeng li]

Dear users,

I am simulating polymer in water and get water density lower than
experimental one at 363K, 1bar. The water model I use is spce.Gromacs
version 4.5.4.

Can it be caused by setting dielectric constant epsilon_r = 3.6, which
is the value of polymer and much smaller than that of water?

If so, can I set the epsilon for water and polymer separately?

Thanks very much in advance.

-Zifeng