[gmx-users] some molecule clashing with another ?

Justin A. Lemkul jalemkul at vt.edu
Thu Dec 31 01:48:51 CET 2009



Chih-Ying Lin wrote:
>  
> Hi
> The follwing is my .out file.
>  From it, can I conclude that some molecule clashing with another ?
>  

No, you can conclude that your system is unstable.  One possible reason is 
atomic clashing, but you cannot say for sure.  General advice on your problem 
(which is encountered frequently, and as such, appears thousands of times in the 
list archive) can be found on the Gromacs wiki site:

http://www.gromacs.org/Documentation/Errors#LINCS.2fSETTLE.2fSHAKE_warnings
http://www.gromacs.org/Documentation/Terminology/Blowing_Up

If you want further help, take the advice that I gave you before - look at the 
trajectory, focusing specifically on the problematic atoms (looks like 366 and 
367 are having problems first, suggesting that either they, or atoms nearby, are 
unstable).  I also asked about the success of your energy minimization, but you 
haven't provided that information.  From the output, it seems that your 
simulation is crashing immediately, suggesting that EM did not work properly, 
and there *may* be unresolved clashes.  You will have to do visual inspection to 
determine if this is the case.

-Justin

>  
> Thank you
> Lin
>  
>  
> Step -2, time -0.002 (ps)  *LINCS WARNING*
> relative constraint deviation after LINCS:
> max 0.044043 (between atoms 366 and 368) rms 0.001724
> bonds that rotated more than 30 degrees:
>  atom 1 atom 2  angle  previous, current, constraint length
>     366    367   36.8    0.1973   0.1301      0.1250
>     366    368   36.6    0.1963   0.1305      0.1250
> starting mdrun 'HEN EGG WHITE LYSOZYME in water'
> 5000 steps,      5.0 ps.
> 
> Step 0, time 0 (ps)  *LINCS WARNING
> *relative constraint deviation after LINCS:
> max 42.623165 (between atoms 1499 and 1518) rms 2.341352
> bonds that rotated more than 30 degrees:
>  atom 1 atom 2  angle  previous, current, constraint length
>    1376   1377   39.1    0.1470   0.1471      0.1470
>    1404   1405   59.8    0.1430   0.2374      0.1430
>    1405   1406   88.5    0.1530   0.2358      0.1530
>    1406   1407   76.6    0.1530   0.1851      0.1530
>    1407   1408   74.3    0.1531   0.2407      0.1530
>    1438   1439   34.8    0.1530   0.1557      0.1530
>    1439   1440   34.4    0.1530   0.1594      0.1530
>    1499   1518   90.0    0.1090   4.7549      0.1090
>    1554   1578   90.0    0.1090   0.2729      0.1090
>    1594   1595   53.5    0.1390   0.1650      0.1390
>    1595   1596   57.1    0.1390   0.1515      0.1390
>    1595   1615   90.3    0.1090   0.5874      0.1090
>    1666   1652   48.5    0.1392   0.1535      0.1390
>    1654   1678   90.1    0.1092   0.4554      0.1090
>    1656   1679   90.2    0.1092   0.1300      0.1090
>    1657   1680   90.0    0.1092   1.6346      0.1090
>    1660   1661   58.0    0.1393   0.1424      0.1390
>    1661   1662   54.5    0.1392   0.1467      0.1390
>    1661   1681   88.9    0.1091   0.1237      0.1090
>    1665   1684   89.8    0.1091   0.3454      0.1090
>    1667   1666   53.1    0.1531   0.1364      0.1530
> Back Off! I just backed up step-1.pdb to ./#step-1.pdb.1#
> Sorry couldn't backup step-1.pdb to ./#step-1.pdb.2#
> Back Off! I just backed up step-1.pdb to ./#step-1.pdb.1#
> Back Off! I just backed up 6LYZ-PR.trr to ./#6LYZ-PR.trr.1#
> Sorry couldn't backup step-1.pdb to ./#step-1.pdb.2#
> Sorry couldn't backup step-1.pdb to ./#step-1.pdb.2#
> Back Off! I just backed up step-1.pdb to ./#step-1.pdb.2#
> Sorry couldn't backup step-1.pdb to ./#step-1.pdb.2#
> Back Off! I just backed up step-1.pdb to ./#step-1.pdb.2#
> Sorry couldn't backup step-1.pdb to ./#step-1.pdb.2#
> Sorry couldn't backup step-1.pdb to ./#step-1.pdb.2#
> Step 0, time 0 (ps)  LINCS WARNING
> relative constraint deviation after LINCS:
> max 597108032.000000 (between atoms 366 and 368) rms 26394490.000000
> bonds that rotated more than 30 degrees:
>  atom 1 atom 2  angle  previous, current, constraint length
>      26     39   52.0    0.1530   0.1699      0.1530
>      39     40   69.4    0.1230   0.1423      0.1230
>      39     41   40.7    0.1330   0.1502      0.1330
>      75     76   36.0    0.1250   0.1252      0.1250
>     133    134   69.5    0.1530   0.1937      0.1530
>     134    135   89.8    0.1470   0.2036      0.1470
>     344    346   42.4    0.1470   0.2090      0.1470
>     346    347   42.2    0.1530   0.2141      0.1530
> *    346    359   63.9    0.1530 26006.0332      0.1530
>     359    360   56.9    0.1230 26006.0469      0.1230
>     359    361   83.2    0.1330 82898.5859      0.1330
>     361    362   77.5    0.1000 82845.7109      0.1000
>     361    363   83.8    0.1470 398710.1875      0.1470
>     363    364   89.3    0.1530 1909291.8750      0.1530
>     363    369   85.2    0.1530 393002.8125      0.1530
>     364    365   90.0    0.1508 31146174.0000      0.1530
>     365    366   90.2    0.1544 66925512.0000      0.1530
>     366    367   92.7    0.1301 73689816.0000      0.1250
>     366    368   87.0    0.1305 74638504.0000      0.1250
>     369    370   72.1    0.1230 65978.3203      0.1230
>     369    371   72.6    0.1330 66864.2812      0.1330
>     371    372   85.7    0.1000 10685.0596      0.1000
>     371    373   61.0    0.1470 10685.1035      0.1470
> *    373    374   33.3    0.1530   0.1896      0.1530
>     373    377   33.5    0.1530   0.1933      0.1530
>     547    548   90.1    0.1089   0.1358      0.1090
>     898    900   89.9    0.1530   0.4741      0.1530
>    1045   1046   47.0    0.1780   0.1783      0.1780
>    1118   1119   36.8    0.1090   0.1069      0.1090
>    1128   1129   31.8    0.1000   0.1019      0.1000
>    1130   1131   35.6    0.1340   0.1334      0.1340
>    1152   1153   89.6    0.1530   0.2937      0.1530
>    1153   1154   90.3    0.1529   2.2321      0.1530
>    1154   1155   89.9    0.1529   7.7561      0.1530
>    1155   1156   90.3    0.1470   8.2649      0.1470
>    1156   1157   60.6    0.1000   0.1543      0.1000
>    1156   1158   49.6    0.1339   0.1783      0.1340
>    1158   1159   48.4    0.1340   0.1038      0.1340
>    1159   1160   86.4    0.1000   0.1375      0.1000
>    1165   1166   45.8    0.1230   0.1207      0.1230
> Back Off! I just backed up step-1.pdb to ./#step-1.pdb.3#
> Sorry couldn't backup step-1.pdb to ./#step-1.pdb.3#
> Back Off! I just backed up step-1.pdb to ./#step-1.pdb.3#
> Back Off! I just backed up step-1.pdb to ./#step-1.pdb.4#
> Back Off! I just backed up step-1.pdb to ./#step-1.pdb.3#
> Back Off! I just backed up step0.pdb to ./#step0.pdb.1#
> Back Off! I just backed up step0.pdb to ./#step0.pdb.2#
> Wrote pdb files with previous and current coordinates
> Back Off! I just backed up step0.pdb to ./#step0.pdb.3#
> Wrote pdb files with previous and current coordinates
> Back Off! I just backed up step0.pdb to ./#step0.pdb.1#
> Sorry couldn't backup step0.pdb to ./#step0.pdb.1#
> Wrote pdb files with previous and current coordinates
> Wrote pdb files with previous and current coordinates
> Back Off! I just backed up step0.pdb to ./#step0.pdb.1#
> Back Off! I just backed up step0.pdb to ./#step0.pdb.4#
> Wrote pdb files with previous and current coordinates
> Back Off! I just backed up step0.pdb to ./#step0.pdb.5#
> Wrote pdb files with previous and current coordinates
> Wrote pdb files with previous and current coordinates
> Wrote pdb files with previous and current coordinates
> Back Off! I just backed up step0.pdb to ./#step0.pdb.6#
> Wrote pdb files with previous and current coordinates
> Terminated
>  
>  
> Chih-Ying Lin wrote:
>  >
>  >
>  > Hi
>  > My simulation broke down and the simulation procedues are as follows.
>  >
>  > 1. center a protein molecule in the simulation box
>  > 2. put 20 ligands around the protein with  " genbox " command
>  > 3. make sure that any atom of the ligands does not overlap on any atom
>  > of the protein with Visulization-software.
>  > 4. solvent addition , with the command " genbox *-vdwd*  0.2   "
>  > 5. Addition of ions, with the command " genion "
>  > 6. Energy minimization of the solvated system
>  > 7. Position restrained MD
>  >
>  > => simulation broke down.
>  > => It is very probable that some molecule clashing with another.
> You can change "probable" to an actual answer if you analyze whatever LINCS
> warnings are occurring (the atoms are listed) and by watching the resulting
> trajectory.
>  > => since i have made sured that any atom of the ligands does not overlap
>  > on any atom of the protein with Visulization-software,
>  >       the clashed pair of the molecules are possible " solvent vs
>  > solvent "    or     "solvent vs protein"       or       "solvent vs
>  > ligand "
> Then you should follow up #4 above with another visual inspection, as 
> you did
> with protein-ligand interactions, in addition to any information printed 
> to the
> log file (as above).
>  > => however, from the Gromacs manual , command "genbox"
>  >      " Solvent molecules are removed from the box where the distance
>  > between any atom of the solute molecule(s) and any atom of the solvent
>  > molecule is less
>  >      than the sum of the VanderWaals radii of both atoms. A database
>  > (vdwradii.dat <http://manual.gromacs.org/current/online/dat.html>) of
>  > VanderWaals radii is read by the program, atoms not in the
>  >      database are assigned a default distance -vdw."
>  >
> So solvent-solvent overlap shouldn't be a problem.
>  > =>  here is    vdwradii.dat  (the ligand is simply made of C, N, O, H)
> Yes, this is standard.
>  > ; Very approximate VanderWaals radii
>  > ; only used for drawing atoms as balls or for calculating atomic overlap.
>  > ; longest matches are used
>  > ; '???' or '*' matches any residue name
>  > ; 'AAA' matches any protein residue name
>  > ???  C     0.15
>  > ???  F     0.12
>  > ???  H     0.04
>  > ???  N     0.110
>  > ???  O     0.105
>  > ???  S     0.16
>  >
>  > My questions are
>  > 1. anything wrong of my simulation procedures ?
> In theory, not really.  What values of potential energy and maximum 
> force did
> the energy minimization converge to?
>  > 2. how to find the clashed molecules ?
>  >
> Read the information printed to the log file (again, I'm assuming you're 
> seeing
> LINCS warnings, but you haven't told us what "broke" means!) and watch the
> trajectory to see where things start to fall apart.  As I suggested to 
> someone
> earlier, if the crash is happening reasonably early, setting "nstxout = 
> 1" is a
> useful diagnostic to capture all frames prior to the crash.
> -Justin
>  > Thank you
>  > Lin
>  >
>  >
>  >
>  >
>  >
>  >
>  >
>  
> 

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

Justin A. Lemkul
Ph.D. Candidate
ICTAS Doctoral Scholar
MILES-IGERT Trainee
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080
http://www.bevanlab.biochem.vt.edu/Pages/Personal/justin

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



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