Dear users, I am trying to do a coarse grained simulation of an octamer of a 350 residue protein in water using gromacs-4.5.3 using martini force field. I got the following error when i started running NPT equilibration
"Step 32, time 0.64 (ps) LINCS WARNING relative constraint deviation after LINCS: rms 16.561310, max 137.568573 (between atoms 626 and 627) bonds that rotated more than 30 degrees: atom 1 atom 2 angle previous, current, constraint length Step 32, time 0.64 (ps) LINCS WARNING relative constraint deviation after LINCS: rms 438.087891, max 3717.233887 (between atoms 580 and 581) bonds that rotated more than 30 degrees: atom 1 atom 2 angle previous, current, constraint length 626 627 121.9 0.2705 36.7207 0.2650 621 622 90.0 0.2756 0.4600 0.2700 624 626 91.5 0.3368 269.7515 0.3300 621 623 90.0 0.2756 0.3172 0.2700 620 624 90.4 0.3164 432.6003 0.3100 622 623 90.0 0.2756 0.3991 0.2700 618 620 85.5 0.3164 477.1006 0.3100 626 627 121.9 0.2705 36.7206 0.2650 615 618 88.6 0.3164 211.2461 0.3100 607 610 141.3 0.3164 14.3253 0.3100 Step 32, time 0.64 (ps) LINCS WARNING relative constraint deviation after LINCS: rms 134.347206, max 2000.691284 (between atoms 4949 and 4946) bonds that rotated more than 30 degrees: atom 1 atom 2 angle previous, current, constraint length 610 612 149.2 0.3164 17.6610 0.3100 612 614 89.7 0.3164 3.1394 0.3100 614 615 150.9 0.3164 9.9306 0.3100 615 618 88.6 0.3164 211.1131 0.3100 618 620 85.5 0.3164 477.0737 0.3100 620 624 90.4 0.3164 432.5994 0.3100 4950 4949 75.8 0.3164 146.5132 0.3100 624 626 91.5 0.3368 269.7514 0.3300 4952 4950 118.9 0.3164 14.6303 0.3100 468 469 90.0 0.2705 24.6834 0.2650 4941 4939 90.0 0.3368 8.5601 0.3300 585 586 61.3 0.2756 0.3361 0.2700 4944 4941 82.5 0.3164 206.9830 0.3100 586 587 90.1 0.2756 0.3137 0.2700 4946 4944 90.0 0.3164 583.5660 0.3100 606 607 90.0 0.3368 6.6314 0.3300 4949 4946 90.0 0.3164 620.5243 0.3100 580 581 91.9 0.4030 1003.9232 0.2700 4954 4952 90.3 0.3164 1.6571 0.3100 580 582 89.8 0.2756 960.9988 0.2700 582 583 98.6 0.2756 592.0677 0.2700 463 464 90.0 0.2654 7.6858 0.2600 581 582 88.8 0.1280 193.0707 0.2700 581 583 91.3 0.2254 514.1149 0.2700 Wrote pdb files with previous and current coordinates Wrote pdb files with previous and current coordinates Segmentation fault (core dumped)" Energy minimization and the NVT equilibration ran without any error or warning. The mdp file used is as shown below; title = Martini define = -DPOSRES integrator = md dt = 0.02 nsteps = 50000 nstcomm = 10 comm-grps = nstxout = 0 nstvout = 0 nstfout = 0 nstlog = 1000 nstenergy = 100 nstxtcout = 1000 xtc_precision = 100 xtc-grps = energygrps = Protein W nstlist = 10 ns_type = grid pbc = xyz rlist = 1.4 coulombtype = Shift rcoulomb_switch = 0.0 rcoulomb = 1.2 epsilon_r = 15 vdw_type = Shift rvdw_switch = 0.9 rvdw = 1.2 tcoupl = v-rescale tc-grps = System tau_t = 1.0 ref_t = 300 Pcoupl = parrinello-rahman Pcoupltype = isotropic tau_p = 5.0 compressibility = 3e-4 ref_p = 1.0 gen_vel = yes gen_temp = 300 gen_seed = 473529 constraints = none constraint_algorithm = Lincs unconstrained_start = no lincs_order = 4 lincs_warnangle = 30 Also the water box after energy minimization showed some gaps towards the edge of the box when visualized using VMD. can anybody please help me on how to overcome this error? Thank you, with regards, Anu -- 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