Did you visualise the system? T in function of time? Epot in function of time?
As a side note (not relevant for PME) the mix of nstlist = 10 and the rlist = 1.0 is pretty bad! You want at least rlist=1.2 when nstlist=5 and rlist=1.4 if nstlist =10. On Apr 25, 2013, at 1:10 PM, ABEL Stephane 175950 <stephane.a...@cea.fr> wrote: > Hello all, > > I am trying to test the martini force field with PME for a charged system > that contains na+, water, surfactant, octane molecules at 298K and P=0.1MPa. > My system works well, if i use the standard shift parameters (correct temp, > and pressure). But for for the simulation with PME , the temp of the system > decrease to 290 K. Below my *.mdp parameters for a NPT equil at 298K > > > integrator = md > dt = 0.020 > nsteps = 10000 ; 200ps > nstcomm = 10 > comm-grps = > ;refcoord_scaling = com > > nstxout = 0 > nstvout = 0 > nstfout = 0 > nstlog = 1000 > nstenergy = 100 > ;nstxtcout = 1000 > xtc_precision = 100 > ;xtc-grps = > energygrps = AOT W ION OCT > > nstlist = 10 > ns_type = grid > pbc = xyz > rlist = 1. > > ; PME parameters > coulombtype = PME > rcoulomb = 1.2 > rvdw = 1.2 > fourierspacing = 0.12 > fourier_nx = 0 > fourier_ny = 0 > fourier_nz = 0 > pme_order = 4 > > tcoupl = v-rescale > tc-grps = AOT_W_ION OCT > tau_t = 1.0 1.0 > ref_t = 298 298 > Pcoupl = berendsen > Pcoupltype = isotropic > tau_p = 1.0 > compressibility = 4.5e-5 > ref_p = 1.0 > > ;gen_vel = no > ;gen_temp = 0 > ;gen_seed = 473529 > > > ; MARTINI and CONSTRAINTS > ; for ring systems and stiff bonds constraints are defined > ; which are best handled using Lincs. > > constraints = none > constraint_algorithm = Lincs > unconstrained_start = no > lincs_order = 4 > lincs_warnangle = 3 > > > Results obtained with W/ PME > > Statistics over 10001 steps using 1001 frames > > Energies (kJ/mol) > Bond G96Angle LJ (SR) Coulomb (SR) Coul. recip. > 1.63789e+04 1.25195e+03 -4.02093e+05 -8.22079e+03 -4.86843e+04 > Potential Kinetic En. Total Energy Temperature Pressure (bar) > -4.41367e+05 7.81801e+04 -3.63187e+05 2.90373e+02 -1.76470e+01 > T-AOT_W_ION T-OCT > 2.90629e+02 2.90357e+02 > > Results W:o PME > > Energies (kJ/mol) > Bond G96Angle LJ (SR) Coulomb (SR) Potential > 1.60482e+04 1.24820e+03 -3.34608e+05 -7.33665e+02 -3.18046e+05 > Kinetic En. Total Energy Temperature Pressure (bar) > 8.02685e+04 -2.37777e+05 2.98129e+02 -3.07123e+01 > > Box-X Box-Y Box-Z > 1.52926e+01 1.52926e+01 1.52926e+01 > > > T-AOT_W_ION T-OCT > 2.98141e+02 2.98129e+02 > > > Did I miss something ? > > > Note that for the moment i do not use the polarizable water model. > > Thanks for your help > > Stephane > > > > > -- > gmx-users mailing list gmx-users@gromacs.org > http://lists.gromacs.org/mailman/listinfo/gmx-users > * Please search the archive at > http://www.gromacs.org/Support/Mailing_Lists/Search before posting! > * Please don't post (un)subscribe requests to the list. Use the > www interface or send it to gmx-users-requ...@gromacs.org. > * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists -- gmx-users mailing list gmx-users@gromacs.org http://lists.gromacs.org/mailman/listinfo/gmx-users * Please search the archive at http://www.gromacs.org/Support/Mailing_Lists/Search before posting! * Please don't post (un)subscribe requests to the list. Use the www interface or send it to gmx-users-requ...@gromacs.org. * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists