[gmx-users] umbrella sampling, LINCS WARNING

Justin Lemkul jalemkul at vt.edu
Thu Jan 4 14:44:51 CET 2018



On 1/4/18 2:48 AM, rose rahmani wrote:
> Hello;
>
> I'm doing umbrella sampling, protein is getting closer to ZnS, but i get
> some step files and run crashed just 107sec to end. Would it be because of
> protein got very close to ZnS? Would you please help me?

A COM distance of 0.3 nm is going to place atoms well within the steep 
LJ repulsive regime, so naturally forces are going to build up. Watch 
the trajectory and see what's happening.

-Justin

> With regards
>
>
> ---------------------
> this is pullf.xvg
>
> 0.0000  -0.000579208
> 0.0020  2.45011
> 0.0040  4.89696
> 0.0060  7.35804
> 0.0080  9.82449
> 0.0100  12.2863
> 0.0120  14.7352
> 0.0140  17.1628
> 0.0160  19.5634
>
> .
> .
> .
> 1956.0480       -100532
> 1956.0500       -100532
> 1956.0520       -100531
> 1956.0540       -100530
> 1956.0560       -100529
> 1956.0580       -100528
> 1956.0600       -100527
> 1956.0620       -100526
> -----------
> this is pullx.xvg
>
> 0.0000  4.287   1.73577
> 0.1000  4.287   1.72023
> 0.2000  4.287   1.73131
> 0.3000  4.287   1.75326
> 0.4000  4.287   1.77348
> 0.5000  4.287   1.76939
> 0.6000  4.287   1.75636
> 0.7000  4.287   1.73677
> 0.8000  4.287   1.71755
> 0.9000  4.287   1.70901
> 1.0000  4.287   1.72336
>
> .
> .
> .
>
> 1953.2000       4.287   0.324765
> 1953.3000       4.287   0.323972
> 1953.4000       4.287   0.326929
> 1953.5000       4.287   0.323881
> 1953.6000       4.287   0.323358
> 1953.7000       4.287   0.325145
> 1953.8000       4.287   0.32516
> 1953.9000       4.287   0.324791
> 1954.0000       4.287   0.325144
> 1954.1000       4.287   0.324902
> 1954.2000       4.287   0.324985
> 1954.3000       4.287   0.324877
> 1954.4000       4.287   0.323429
> 1954.5000       4.287   0.32637
> 1954.6000       4.287   0.324941
> 1954.7000       4.
>
> -----------------------------------
> this is md_pull.mdp;
>
> integrator               = md
> dt                       = 0.002
> nsteps                   = 1000000
> nstxout                  = 5000
> nstvout                  = 5000
> nstfout                  = 500
> nstlog                   = 500
> nstenergy                = 1000
> nstxtcout                = 1000
> nstlist                  = 10
> rlist                    = 1.5
> coulombtype              = pme
> rcoulomb                 = 1.5
> vdwtype                  = Switch
> rvdw_switch              = 1.0
> rvdw                     = 1.2
> pcoupl                   = no
> gen_vel                  = no
> constraints              = h-bonds
> ns_type                  = grid
> pbc                      = xy
> freezegrps               = WAL ZnS
> freezedim                = Y Y Y Y Y Y
> energygrp-excl           = WAL WAL ZnS ZnS
> energygrps               = SOL WAL ZnS Protein NA CL
> nwall                    = 2
> wall-atomtype            = C C
> wall-type                = 9-3
> wall-density             = 150 150
> wall-ewald-zfac          = 3
> ewald-geometry           = 3dc
> fourierspacing           = 0.12
> tcoupl                   = v-rescale
> tc-grps                  = System
> tau-t                    = 0.1
> ref-t                    = 300
>
> ; Pull code
> pull                    = umbrella
> pull_ngroups            = 1
> pull_group0             = ZnS
> pull_group1             = Protein
> pull_geometry           = direction
> pull_vec1               = 0 0 1
> pull_dim                = N N Y
> pull_rate1              = -0.011        ; 1 nm per  ns
> pull_k1                 = 5000
> pull_start              = yes
> pull_nstxout            = 50
>
> --------------------------
> This is pull.job
>
>
> Step 978195, time 1956.39 (ps)  LINCS WARNING
> relative constraint deviation after LINCS:
> rms 0.000004, max 0.000010 (between atoms 782 and 780)
> bonds that rotated more than 30 degrees:
>   atom 1 atom 2  angle  previous, current, constraint length
>      770    769   61.4    0.1090   0.1090      0.1090
>      779    778   42.0    0.1010   0.1010      0.1010
>
> Step 978197, time 1956.39 (ps)  LINCS WARNING
> relative constraint deviation after LINCS:
> rms 0.429802, max 1.468930 (between atoms 783 and 780)
> bonds that rotated more than 30 degrees:
>   atom 1 atom 2  angle  previous, current, constraint length
>      773    771   90.0    0.1112   0.1202      0.1090
>      770    769   32.8    0.1090   0.1090      0.1090
>      779    778   90.0    0.1010   0.1232      0.1010
>      783    780   90.0    0.1090   0.2691      0.1090
> Wrote pdb files with previous and current coordinates
>
> Step 978198, time 1956.4 (ps)  LINCS WARNING
> relative constraint deviation after LINCS:
> rms 2.212948, max 5.521000 (between atoms 773 and 771)
> bonds that rotated more than 30 degrees:
>   atom 1 atom 2  angle  previous, current, constraint length
>      773    771   90.0    0.1202   0.7108      0.1090
>      772    771   47.8    0.1105   0.1031      0.1090
>      770    769   90.0    0.1090   0.1142      0.1090
>      779    778   90.0    0.1232   0.6381      0.1010
>      783    780   57.8    0.2691   0.1086      0.1090
> Wrote pdb files with previous and current coordinates
>
> Step 978199, time 1956.4 (ps)  LINCS WARNING
> relative constraint deviation after LINCS:
> rms 0.451943, max 1.210712 (between atoms 770 and 769)
> bonds that rotated more than 30 degrees:
>   atom 1 atom 2  angle  previous, current, constraint length
>      773    771   90.0    0.7108   0.1628      0.1090
>      772    771   36.8    0.1031   0.1131      0.1090
>      770    769   90.0    0.1142   0.2410      0.1090
>      779    778   56.6    0.6381   0.1010      0.1010
>      783    780   90.0    0.1086   0.2027      0.1090
> Wrote pdb files with previous and current coordinates
> vol 0.70  imb F 27%
> Step 978200, time 1956.4 (ps)  LINCS WARNING
> relative constraint deviation after LINCS:
> rms 3.021436, max 9.508962 (between atoms 769 and 770)
> bonds that rotated more than 30 degrees:
>   atom 1 atom 2  angle  previous, current, constraint length
>      769    770   90.0    0.2410   1.1455      0.1090
>      773    771   90.0    0.1628   0.6838      0.1090
>      772    771   90.0    0.1131   0.6719      0.1090
>      779    778   90.0    0.1010   0.2717      0.1010
>      783    780   90.0    0.2027   0.1641      0.1090
>      782    780   90.0    0.1112   0.1303      0.1090
>      781    780   90.0    0.1097   0.2685      0.1090
>
> step 978200: Water molecule starting at atom 991 can not be settled.
> Check for bad contacts and/or reduce the timestep if appropriate.
> Wrote pdb files with previous and current coordinates
> ^Mstep 978200, remaining runtime:   107 s

-- 
==================================================

Justin A. Lemkul, Ph.D.
Assistant Professor
Virginia Tech Department of Biochemistry

303 Engel Hall
340 West Campus Dr.
Blacksburg, VA 24061

jalemkul at vt.edu | (540) 231-3129
http://www.biochem.vt.edu/people/faculty/JustinLemkul.html

==================================================



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