[gmx-users] High pressure in coarse-grained parametrization

[Alex]

Dear all,

Here is a part of the *.mdp file I am using in coarse-grained
parametrization (Iterative Boltzmann Inversion method) of a molecule by
votca.

integrator               = sd
tinit                    = 0
dt                       = 0.00002
nsteps                   = 50000000
init_step                = 0
...
*tcoupl                   = no*
tc-grps                  = System
tau_t                    = 0.02
*ref_t                    = 298.15*
*Pcoupl                   = no*
pcoupltype               = isotropic
tau_p                    = 0.5
compressibility          = 4.5e-5
*ref_p                    = 1.0*
gen_vel                  = yes
gen_temp                 = 298.15
gen_seed                 = -1

The temperature is fully fine in each step of IBI, but the pressure is such
as below in the second step (it is twice in the first step IBI):
Energy                      Average   Err.Est.       RMSD  Tot-Drift
-------------------------------------------------------------------------------
Pressure                    1143.92         14    2686.58   -67.2573  (bar)

I was wondering if it is normal as I am using sd integrator? If not, what
can I do to make it normal?

Thank you.
Regards,
Alex