[gmx-users] Error during NVT equillibration with nvt.log file

ram bio rmbio861 at gmail.com
Fri Oct 16 17:40:14 CEST 2009


Dear Gromacs users,

I am doing protein in lipid-bilayer simulation and i am following the
procedure as per justin tutorial. I am able to insert the protein in
lipid bilayer and minimize the system as per Inflategro
procedure,during the total procedure the system was minimized in every
step.Then, I solvated and ionized sytem and minimized using the
following mdp file:

; minim.mdp - used as input into grompp to generate em.tpr
; Parameters describing what to do, when to stop and what to save
define = -DSTRONG_POSRES
integrator      = steep         ; Algorithm (steep = steepest descent
minimization)
emtol           = 500.0         ; Stop minimization when the maximum
force < 1000.0 kJ/mol/nm
emstep          = 0.01          ; Energy step size
nsteps          = 50000         ; Maximum number of (minimization)
steps to perform

; Parameters describing how to find the neighbors of each atom and how
to calculate the interactions
nstlist         = 1             ; Frequency to update the neighbor
list and long range forces
ns_type         = grid          ; Method to determine neighbor list
(simple, grid)
rlist           = 1.2           ; Cut-off for making neighbor list
(short range forces)
coulombtype     = PME           ; Treatment of long range
electrostatic interactions
rcoulomb        = 1.2           ; Short-range electrostatic cut-off
rvdw            = 1.2           ; Short-range Van der Waals cut-off
pbc             = xyz           ; Periodic Boundary Conditions (yes/no)

the output was as follows:

Steepest Descents converged to Fmax < 500 in 4770 steps
Potential Energy  = -3.8820288e+05
Maximum force     =  4.4803549e+02 on atom 3573
Norm of force     =  1.7854408e+01

As the potential energy and Fmax values were agreeable , I proceeded
to equillibrate the system using NVT.

The mdp file used for NVT equillibration is :

title           = NVT equilibration
define          = -DPOSRES      ; position restrain the protein
; Run parameters
integrator      = md            ; leap-frog integrator
nsteps          = 50000         ; 2 * 50000 = 100 ps
dt              = 0.002         ; 2 fs
; Output control
nstxout         = 100           ; save coordinates every 0.2 ps
nstvout         = 100           ; save velocities every 0.2 ps
nstenergy       = 100           ; save energies every 0.2 ps
nstlog          = 100           ; update log file every 0.2 ps
; Bond parameters
continuation    = no            ; first dynamics run
constraint_algorithm = lincs    ; holonomic constraints
constraints     = all-bonds     ; all bonds (even heavy atom-H bonds)
constrained
lincs_iter      = 1             ; accuracy of LINCS
lincs_order     = 4             ; also related to accuracy
; Neighborsearching
ns_type         = grid          ; search neighboring grid cels
nstlist         = 5             ; 10 fs
rlist           = 1.2           ; short-range neighborlist cutoff (in nm)
rcoulomb        = 1.2           ; short-range electrostatic cutoff (in nm)
rvdw            = 1.2           ; short-range van der Waals cutoff (in nm)
; Electrostatics
coulombtype     = PME           ; Particle Mesh Ewald for long-range
electrostatics
pme_order       = 4             ; cubic interpolation
fourierspacing  = 0.16          ; grid spacing for FFT
; Temperature coupling is on
tcoupl          = V-rescale     ; modified Berendsen thermostat
tc-grps         = Protein DPPC SOL_CL-  ; three coupling groups - more accurate
tau_t           = 0.1   0.1     0.1     ; time constant, in ps
ref_t           = 323   323     323     ; reference temperature, one
for each group, in K
; Pressure coupling is off
pcoupl          = no            ; no pressure coupling in NVT
; Periodic boundary conditions
pbc             = xyz           ; 3-D PBC
; Dispersion correction
DispCorr        = EnerPres      ; account for cut-off vdW scheme
; Velocity generation
gen_vel         = yes           ; assign velocities from Maxwell distribution
gen_temp        = 323           ; temperature for Maxwell distribution
gen_seed        = -1            ; generate a random seed
; COM motion removal
; These options remove motion of the protein/bilayer relative to the
solvent/ions
nstcomm         = 1
comm-mode       = Linear
comm-grps       = Protein_DPPC SOL_CL-


and the output error for the mdrun is as under:

Step 0, time 0 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 0.002307, max 0.080808 (between atoms 3569 and 3570)
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
starting mdrun 'Protein in DPPC in water'
50000 steps,    100.0 ps.

Step 0, time 0 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 31.024508, max 1431.875854 (between atoms 448 and 450)
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
   453    455   49.9    0.1331   0.2004      0.1330
   453    454   50.5    0.1231   0.1762      0.1230
   451    452   89.9    0.1003  29.4775      0.1000
   450    451   88.8    0.1364 173.8469      0.1360
   448    450   89.4    0.1395 199.1697      0.1390
   448    449   87.6    0.1093  41.7673      0.1090
   446    450   89.5    0.1396 171.8707      0.1390
   446    447   86.7    0.1093  29.7511      0.1090
   444    448   84.1    0.1393  29.2753      0.1390
   444    445   85.6    0.1093  16.5969      0.1090
   442    446   83.9    0.1393  31.1317      0.1390
   442    443   81.1    0.1093   7.2542      0.1090
   441    444   84.4    0.1396  16.9881      0.1390
   441    442   75.4    0.1396   5.1277      0.1390
   440    441   54.3    0.1534   4.4912      0.1530
   439    453   71.5    0.1532   0.8628      0.1530
   439    440   85.1    0.1535   3.5898      0.1530
   437    439   73.6    0.1472   0.8916      0.1470
   437    438   55.1    0.1001   0.1549      0.1000
   435    437   50.7    0.1331   0.2031      0.1330
  3589   3590   34.2    0.1232   0.1707      0.1230
  3588   3589  148.5    0.1365   0.9604      0.1360
  3577   3578   40.2    0.1532   0.2055      0.1530
  3576   3577  162.3    0.1532   0.1352      0.1530
  3575   3576   60.7    0.1536   2.3589      0.1530
  3574   3575  127.4    0.1602   4.5642      0.1530
  3573   3574   72.3    0.1583  43.2879      0.1530
  3572   3573   95.7    0.1638 186.7845      0.1530
  3570   3572   82.5    0.1561 179.5817      0.1530
  3570   3571  110.9    0.1297  27.9543      0.1230
  3569   3570  127.4    0.1470  29.7186      0.1360
  3568   3587  143.4    0.1552   8.5459      0.1530
  3567   3568  107.8    0.1542   8.2206      0.1530
  3566   3567   37.6    0.1432   0.4594      0.1430
  3563   3566  115.0    0.1610   0.1509      0.1610
step 0Warning: 1-4 interaction between 435 and 440 at distance 3.609
which is larger than the 1-4 table size 2.200 nm
These are ignored for the rest of the simulation
This usually means your system is exploding,
if not, you should increase table-extension in your mdp file
or with user tables increase the table size
Segmentation fault

I have used a minimized protein as a starting structure for insertion,
and the coordinates of the atoms in the pdb file are as follows:

ATOM    435  CD  ILE    45      59.176  46.081  35.828  1.00  0.00
ATOM    436  C   ILE    45      55.567  47.340  36.239  1.00  0.00
ATOM    437  O   ILE    45      55.953  47.123  37.392  1.00  0.00
ATOM    438  N   TYR    46      54.494  48.075  35.978  1.00  0.00
ATOM    439  H   TYR    46      54.293  48.397  35.053  1.00  0.00
ATOM    440  CA  TYR    46      53.607  48.618  37.037  1.00  0.00

and my nvt.log file is as foolows;

                                :-)  mdrun  (-:

Input Parameters:
   integrator           = md
   nsteps               = 50000
   init_step            = 0
   ns_type              = Grid
   nstlist              = 5
   ndelta               = 2
   nstcomm              = 1
   comm_mode            = Linear
   nstlog               = 100
   nstxout              = 100
   nstvout              = 100
   nstfout              = 0
   nstenergy            = 100
   nstxtcout            = 0
   init_t               = 0
   delta_t              = 0.002
   xtcprec              = 1000
   nkx                  = 48
   nky                  = 48
   nkz                  = 60
   pme_order            = 4
   ewald_rtol           = 1e-05
   ewald_geometry       = 0
   epsilon_surface      = 0
   optimize_fft         = FALSE
   ePBC                 = xyz
   bPeriodicMols        = FALSE
   bContinuation        = FALSE
   bShakeSOR            = FALSE
   etc                  = V-rescale
   epc                  = No
   epctype              = Isotropic
   tau_p                = 1
   ref_p (3x3):
      ref_p[    0]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
      ref_p[    1]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
      ref_p[    2]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
   compress (3x3):
      compress[    0]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
      compress[    1]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
      compress[    2]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
   refcoord_scaling     = No
   posres_com (3):
      posres_com[0]= 0.00000e+00
      posres_com[1]= 0.00000e+00
      posres_com[2]= 0.00000e+00
   posres_comB (3):
      posres_comB[0]= 0.00000e+00
      posres_comB[1]= 0.00000e+00
      posres_comB[2]= 0.00000e+00
   andersen_seed        = 815131
   rlist                = 1.2
   rtpi                 = 0.05
   coulombtype          = PME
   rcoulomb_switch      = 0
   rcoulomb             = 1.2
   vdwtype              = Cut-off
   rvdw_switch          = 0
   rvdw                 = 1.2
   epsilon_r            = 1
   epsilon_rf           = 1
   tabext               = 1
   implicit_solvent     = No
   gb_algorithm         = Still
   gb_epsilon_solvent   = 80
   nstgbradii           = 1
   rgbradii             = 2
   gb_saltconc          = 0
   gb_obc_alpha         = 1
   gb_obc_beta          = 0.8
   gb_obc_gamma         = 4.85
   sa_surface_tension   = 2.092
   DispCorr             = EnerPres
   free_energy          = no
   init_lambda          = 0
   sc_alpha             = 0
   sc_power             = 0
   sc_sigma             = 0.3
   delta_lambda         = 0
   nwall                = 0
   wall_type            = 9-3
   wall_atomtype[0]     = -1
   wall_atomtype[1]     = -1
   wall_density[0]      = 0
   wall_density[1]      = 0
   wall_ewald_zfac      = 3
   pull                 = no
   disre                = No
   disre_weighting      = Conservative
   disre_mixed          = FALSE
   dr_fc                = 1000
   dr_tau               = 0
   nstdisreout          = 100
   orires_fc            = 0
   orires_tau           = 0
   nstorireout          = 100
   dihre-fc             = 1000
   em_stepsize          = 0.01
   em_tol               = 10
   niter                = 20
   fc_stepsize          = 0
   nstcgsteep           = 1000
   nbfgscorr            = 10
   ConstAlg             = Lincs
   shake_tol            = 1e-04
   lincs_order          = 4
   lincs_warnangle      = 30
   lincs_iter           = 1
   bd_fric              = 0
   ld_seed              = 1993
   cos_accel            = 0
   deform (3x3):
      deform[    0]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
      deform[    1]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
      deform[    2]={ 0.00000e+00,  0.00000e+00,  0.00000e+00}
   userint1             = 0
   userint2             = 0
   userint3             = 0
   userint4             = 0
   userreal1            = 0
   userreal2            = 0
   userreal3            = 0
   userreal4            = 0
grpopts:
   nrdf:     6048.01       12219       45018
   ref_t:         323         323         323
   tau_t:         0.1         0.1         0.1
anneal:          No          No          No
ann_npoints:           0           0           0
   acc:	           0           0           0
   nfreeze:           N           N           N
   energygrp_flags[  0]: 0
   efield-x:
      n = 0
   efield-xt:
      n = 0
   efield-y:
      n = 0
   efield-yt:
      n = 0
   efield-z:
      n = 0
   efield-zt:
      n = 0
   bQMMM                = FALSE
   QMconstraints        = 0
   QMMMscheme           = 0
   scalefactor          = 1
qm_opts:
   ngQM                 = 0
Table routines are used for coulomb: TRUE
Table routines are used for vdw:     FALSE
Will do PME sum in reciprocal space.

++++ PLEASE READ AND CITE THE FOLLOWING REFERENCE ++++
U. Essman, L. Perela, M. L. Berkowitz, T. Darden, H. Lee and L. G. Pedersen
A smooth particle mesh Ewald method
J. Chem. Phys. 103 (1995) pp. 8577-8592
-------- -------- --- Thank You --- -------- --------

Using a Gaussian width (1/beta) of 0.384195 nm for Ewald
Cut-off's:   NS: 1.2   Coulomb: 1.2   LJ: 1.2
System total charge: 0.000
Generated table with 1100 data points for Ewald.
Tabscale = 500 points/nm
Generated table with 1100 data points for LJ6.
Tabscale = 500 points/nm
Generated table with 1100 data points for LJ12.
Tabscale = 500 points/nm
Generated table with 1100 data points for 1-4 COUL.
Tabscale = 500 points/nm
Generated table with 1100 data points for 1-4 LJ6.
Tabscale = 500 points/nm
Generated table with 1100 data points for 1-4 LJ12.
Tabscale = 500 points/nm

Enabling SPC water optimization for 7497 molecules.

Configuring nonbonded kernels...
Testing AMD 3DNow support... not present.
Testing ia32 SSE support... present.


Removing pbc first time

Initializing LINear Constraint Solver

++++ PLEASE READ AND CITE THE FOLLOWING REFERENCE ++++
B. Hess and H. Bekker and H. J. C. Berendsen and J. G. E. M. Fraaije
LINCS: A Linear Constraint Solver for molecular simulations
J. Comp. Chem. 18 (1997) pp. 1463-1472
-------- -------- --- Thank You --- -------- --------

The number of constraints is 9045

++++ PLEASE READ AND CITE THE FOLLOWING REFERENCE ++++
S. Miyamoto and P. A. Kollman
SETTLE: An Analytical Version of the SHAKE and RATTLE Algorithms for Rigid
Water Models
J. Comp. Chem. 13 (1992) pp. 952-962
-------- -------- --- Thank You --- -------- --------

Center of mass motion removal mode is Linear
We have the following groups for center of mass motion removal:
  0:  Protein_DPPC
  1:  SOL_CL-

++++ PLEASE READ AND CITE THE FOLLOWING REFERENCE ++++
G. Bussi, D. Donadio and M. Parrinello
Canonical sampling through velocity rescaling
J. Chem. Phys. 126 (2007) pp. 014101
-------- -------- --- Thank You --- -------- --------

There are: 31609 Atoms
Max number of connections per atom is 28
Total number of connections is 138849
Max number of graph edges per atom is 4
Total number of graph edges is 48078

Constraining the starting coordinates (step 0)

Constraining the coordinates at t0-dt (step 0)
RMS relative constraint deviation after constraining: 6.80e-04
Initial temperature: 338.401 K

Started mdrun on node 0 Sun Jul  5 17:09:45 2009

           Step           Time         Lambda
              0        0.00000        0.00000

Grid: 10 x 10 x 13 cells
Long Range LJ corr.: <C6> 9.7327e-04
Long Range LJ corr.: Epot   -2200.19, Pres:   -136.406, Vir:    2200.19
   Energies (kJ/mol)
          Angle       G96Angle    Proper Dih. Ryckaert-Bell.  Improper Dih.
    2.20077e+04    8.54042e+03    6.78950e+03    4.34650e+03    3.03266e+03
          LJ-14     Coulomb-14        LJ (SR)  Disper. corr.   Coulomb (SR)
    4.76527e+03    5.50236e+04    8.36617e+06   -2.20019e+03   -4.46844e+05
   Coul. recip. Position Rest.      Potential    Kinetic En.   Total Energy
   -1.65524e+05    1.07769e+01    7.85612e+06    5.88813e+10    5.88892e+10
  Conserved En.    Temperature Pressure (bar)  Cons. rmsd ()
    5.88892e+10    2.23805e+08    1.21713e+09    3.10245e+01

Please help me to proceed further and let me know where are the
mistakes lying and how to overcome them.

Thanks in advance,

Ram



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