your tau_t is 1 ps and you want to increase the temperature by 300 K in 10 ps. I doubt that this is possible. Try heating over a longer period of time. The longer the period, the closer you will get to your target temperature. Why do you need to do the heating over 10 ps? Also, when using any deterministic integrator, I think that you are asking for problems anyway based on a rapid scaling of forces into velocities. Try doing this over 1 ns instead. The alternative, reducing tau_t, is not a good idea.
Chris. -- original message -- In my test simulation annealing I'm trying to heat my system from 0 K to 300 k after 10 ps of run. But at the end I see the temperature didn't reach to 300 K , it's near around 22 K. So can anyone please correct me in my .mdp file ? constraints = none integrator = md-vv dt = 0.0005 ; 1fs nsteps = 20000 ; 30ps nstcomm = 1 nstxout = 1000 ; frequency to write coordinates to output trajectory nstvout = 0 ; frequency to write velocities to output trajectory; the last velocities are always written nstfout = 0 ; frequency to write forces to output trajectory nstlog = 1000 ; frequency to write energies to log file nstenergy = 1000 ; frequency to write energies to edr file nstcalcenergy = 1000 vdwtype = cut-off coulombtype = PME pbc = xyz table-extension = 20.0 nstlist = 100 ns_type = grid rlist = 1.2 rcoulomb = 1.2 rvdw = 1.2 comm-grps = system optimize_fft = yes ;heating annealing = single annealing_npoints = 2 annealing_time = 0 10 annealing_temp = 0 300 ld_seed = 8072012 ;nsttcouple = 0.001 ;temperature coupling is on Tcoupl = Nose-Hoover tau_t = 1.0 tc_grps = system ref_t = 0 ;Pressure coupling is off Pcoupl = no ; Generate velocites is on gen_vel = yes gen_temp = 0 gen_seed = 8042012 THE .log FILE Constraining the starting coordinates (step 0) RMS relative constraint deviation after constraining: 0.00e+00 Initial temperature: 0 K Started mdrun on node 0 Tue Nov 6 21:21:05 2012 Step Time Lambda 0 0.00000 0.00000 Grid: 14 x 14 x 14 cells Current ref_t for group System: 0.0 Energies (kJ/mol) Bond Angle Proper Dih. Improper Dih. LJ-14 6.98365e+02 2.31495e+03 4.34144e+03 9.32563e+01 3.06280e+03 Coulomb-14 LJ (SR) Coulomb (SR) Coul. recip. Potential 4.90527e+04 3.16274e+05 -1.60409e+06 -1.10076e+05 -1.33833e+06 Kinetic En. Total Energy Conserved En. Temperature Pressure (bar) 0.00000e+00 -1.33833e+06 -1.33833e+06 0.00000e+00 1.63793e+02 Step Time Lambda 1000 0.50000 0.00000 Current ref_t for group System: 15.0 Energies (kJ/mol) Bond Angle Proper Dih. Improper Dih. LJ-14 5.91509e+02 2.27120e+03 4.37612e+03 1.01524e+02 3.13151e+03 Coulomb-14 LJ (SR) Coulomb (SR) Coul. recip. Potential 4.91902e+04 2.58594e+05 -1.55303e+06 -1.10344e+05 -1.34512e+06 Kinetic En. Total Energy Conserved En. Temperature Pressure (bar) 6.82988e+03 -1.33829e+06 -1.33829e+06 1.08252e+01 -4.10650e+03 Step Time Lambda 2000 1.00000 0.00000 Current ref_t for group System: 30.0 Energies (kJ/mol) Bond Angle Proper Dih. Improper Dih. LJ-14 5.90602e+02 2.30240e+03 4.39329e+03 1.10298e+02 3.15642e+03 Coulomb-14 LJ (SR) Coulomb (SR) Coul. recip. Potential 4.91731e+04 2.60786e+05 -1.55644e+06 -1.10395e+05 -1.34632e+06 Kinetic En. Total Energy Conserved En. Temperature Pressure (bar) 8.05310e+03 -1.33827e+06 -1.33827e+06 1.27640e+01 -3.72695e+03 .............. .............. Current ref_t for group System: 255.0 Energies (kJ/mol) Bond Angle Proper Dih. Improper Dih. LJ-14 6.07478e+02 2.34899e+03 4.43725e+03 1.08744e+02 3.17997e+03 Coulomb-14 LJ (SR) Coulomb (SR) Coul. recip. Potential 4.91213e+04 2.69271e+05 -1.57036e+06 -1.10532e+05 -1.35182e+06 Kinetic En. Total Energy Conserved En. Temperature Pressure (bar) 1.39095e+04 -1.33791e+06 -1.33791e+06 2.20464e+01 -3.08283e+03 Step Time Lambda 18000 9.00000 0.00000 Current ref_t for group System: 270.0 Energies (kJ/mol) Bond Angle Proper Dih. Improper Dih. LJ-14 6.22035e+02 2.35774e+03 4.41413e+03 1.07439e+02 3.16535e+03 Coulomb-14 LJ (SR) Coulomb (SR) Coul. recip. Potential 4.91418e+04 2.69872e+05 -1.57111e+06 -1.10528e+05 -1.35195e+06 Kinetic En. Total Energy Conserved En. Temperature Pressure (bar) 1.40644e+04 -1.33789e+06 -1.33789e+06 2.22919e+01 -3.09464e+03 Step Time Lambda 19000 9.50000 0.00000 Current ref_t for group System: 285.0 Energies (kJ/mol) Bond Angle Proper Dih. Improper Dih. LJ-14 6.31355e+02 2.37456e+03 4.40719e+03 1.06998e+02 3.16961e+03 Coulomb-14 LJ (SR) Coulomb (SR) Coul. recip. Potential 4.90783e+04 2.69394e+05 -1.57063e+06 -1.10548e+05 -1.35202e+06 Kinetic En. Total Energy Conserved En. Temperature Pressure (bar) 1.41424e+04 -1.33788e+06 -1.33788e+06 2.24154e+01 -3.29328e+03 Step Time Lambda 20000 10.00000 0.00000 Writing checkpoint, step 20000 at Tue Nov 6 21:39:16 2012 Current ref_t for group System: 300.0 Energies (kJ/mol) Bond Angle Proper Dih. Improper Dih. LJ-14 6.25626e+02 2.36220e+03 4.42870e+03 1.05787e+02 3.16930e+03 Coulomb-14 LJ (SR) Coulomb (SR) Coul. recip. Potential 4.91428e+04 2.69664e+05 -1.57107e+06 -1.10530e+05 -1.35210e+06 Kinetic En. Total Energy Conserved En. Temperature Pressure (bar) 1.42464e+04 -1.33786e+06 -1.33786e+06 2.25803e+01 -3.15481e+03 Thanks for ur help. -- 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