[gmx-users] Parametrisation of the cyclic nucleotides in Gromos force fields

James Starlight jmsstarlight at gmail.com
Fri Dec 7 17:42:37 CET 2012


Justin,

ligand-only simulation in vacuum have been finished with the same errors :)

Step 19200, time 38.4 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 0.025443, max 0.140660 (between atoms 1 and 3)
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
      1      2   52.2    0.1033   0.0985      0.1000
      1      3   90.1    0.1168   0.1141      0.1000

Step 19200, time 38.4 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 0.025376, max 0.140474 (between atoms 1 and 3)
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
      1      2   52.0    0.1033   0.0988      0.1000
      1      3   90.0    0.1168   0.1140      0.1000
step 19200, will finish Sat Dec  8 04:10:49 2012
Step 19201, time 38.402 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 0.052715, max 0.293316 (between atoms 1 and 3)
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
      1      2   49.3    0.0988   0.0993      0.1000
      1      3   90.0    0.1140   0.1293      0.1000

Step 19201, time 38.402 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 0.052900, max 0.294281 (between atoms 1 and 3)
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
      1      2   49.6    0.0988   0.0989      0.1000
      1      3   90.0    0.1140   0.1294      0.1000

Step 19202, time 38.404 (ps)  LINCS WARNING
relative constraint deviation after LINCS:
rms 0.035783, max 0.198482 (between atoms 1 and 3)
bonds that rotated more than 30 degrees:
 atom 1 atom 2  angle  previous, current, constraint length
      1      2   33.3    0.0989   0.0984      0.1000
      1      3   89.9    0.1294   0.1198      0.1000

-------------------------------------------------------
Program mdrun, VERSION 4.5.4
Source code file: /tmp/gromacs-4.5.4/src/mdlib/constr.c, line: 176

Fatal error:
Too many LINCS warnings (1000)


ITs intresting that the same files (like step-1c_n11.pdb) have been
produced already during CG minimisation phase but the system have not
been crashed. So I suppoe that the problem is in geometry of the
mollecule. The direct comparison of the bonds and angles with the rtp
(DGUA) is non trivial again because of differs in the file formats
representation :)


James

2012/12/7 Justin Lemkul <jalemkul at vt.edu>:
>
>
> On 12/7/12 10:41 AM, James Starlight wrote:
>>
>> Today I've tried to simulate complexes of my protein with the cyclic
>> GMP parametrized by ATB's. (below the recent parametrisation for
>> charges of that molecule done by am1 algorithm)
>>
>> [ moleculetype ]
>> ; Name   nrexcl
>> _N4P     3
>> [ atoms ]
>> ;  nr  type  resnr  resid  atom  cgnr  charge    mass    total_charge
>>      1    NT    1    _N4P     N2    1   -0.848  14.0067
>>      2     H    1    _N4P    H22    1    0.424   1.0080
>>      3     H    1    _N4P    H21    1    0.424   1.0080      ;  0.000
>>      4    NR    1    _N4P     N1    2   -0.684  14.0067
>>      5     H    1    _N4P     H1    2    0.437   1.0080
>>      6     C    1    _N4P     C2    2    0.779  12.0110
>>      7    NR    1    _N4P     N3    2   -0.678  14.0067
>>      8     C    1    _N4P     C4    2    0.440  12.0110
>>      9    NR    1    _N4P     N9    2   -0.294  14.0067      ;  0.000
>>     10     C    1    _N4P     C8    3    0.272  12.0110
>>     11    HC    1    _N4P    H01    3    0.141   1.0080
>>     12     O    1    _N4P     O6    3   -0.555  15.9994
>>     13     C    1    _N4P     C6    3    0.608  12.0110
>>     14     C    1    _N4P     C5    3    0.101  12.0110
>>     15    NR    1    _N4P     N7    3   -0.567  14.0067      ;  0.000
>>     16    OE    1    _N4P    O4*    4   -0.451  15.9994
>>     17   CH1    1    _N4P    C1*    4    0.451  13.0190      ;  0.000
>>     18    OA    1    _N4P    O5*    5   -0.394  15.9994
>>     19     P    1    _N4P    PAQ    5    0.974  30.9738
>>     20    OM    1    _N4P    OAR    5   -0.616  15.9994
>>     21    OA    1    _N4P    O3*    5   -0.390  15.9994
>>     22    OA    1    _N4P    OAS    5   -0.584  15.9994
>>     23     H    1    _N4P    H03    5    0.491   1.0080
>>     24   CH2    1    _N4P    C5*    5    0.281  14.0270
>>     25   CH1    1    _N4P    C4*    5    0.238  13.0190      ;  0.000
>>     26   CH1    1    _N4P    C3*    6    0.000  13.0190      ;  0.000
>>     27   CH1    1    _N4P    C2*    7    0.181  13.0190
>>     28    OA    1    _N4P    O2*    7   -0.645  15.9994
>>     29     H    1    _N4P    H8M    7    0.464   1.0080      ;  0.000
>>
>> In all cases my system have always been crushed after equilibration
>> run ( during that phase with the posres applied on both protein as
>> well as ligand the system was stabile) with the errors like
>>
>> Step 19, time 0.038 (ps)  LINCS WARNING
>> relative constraint deviation after LINCS:
>> rms 1.203662, max 11.750027 (between atoms 4289 and 4287)
>> bonds that rotated more than 30 degrees:
>>   atom 1 atom 2  angle  previous, current, constraint length
>>     4288   4287   89.5    0.2277   1.1291      0.1000
>>     4292   4287   90.5    0.1304   0.9898      0.1350
>>     4289   4287   90.4    0.1056   1.2750      0.1000
>>     4318   4303   30.8    0.1531   0.1816      0.1530
>>     4304   4303   45.2    0.1097   0.1531      0.1090
>>     4309   4310   90.0    0.2629   0.3419      0.1000
>>     4299   4290   84.2    0.1404   0.1641      0.1400
>>     4292   4290   89.4    0.1362   0.5025      0.1380
>>     4291   4290   89.2    0.1563   0.2142      0.1000
>>     4293   4292   89.1    0.1252   0.5682      0.1320
>>     4294   4293   78.1    0.1387   0.3906      0.1350
>>     4300   4294   92.2    0.1385   0.4639      0.1390
>>     4295   4294   91.1    0.1365   0.5711      0.1380
>>     4303   4295   43.4    0.1482   0.1954      0.1470
>>     4296   4295   36.6    0.1408   0.1593      0.1400
>>     4301   4296   89.9    0.1323   0.5162      0.1320
>>     4297   4296   32.5    0.1089   0.1343      0.1090
>>     4299   4298   87.0    0.1230   0.2758      0.1230
>>     4300   4299   89.8    0.1431   0.5922      0.1430
>>     4301   4300   79.0    0.1381   0.1928      0.1380
>>
>>
>> Fatal error:
>> 1 particles communicated to PME node 26 are more than 2/3 times the
>> cut-off out of the domain decomposition cell of their charge group in
>> dimension y.
>> This usually means that your system is not well equilibrated.
>> For more information and tips for troubleshooting, please check the
>> GROMACS
>>
>> After that my system have been crashed and than produced many
>> step*.pdb files in the work dirr.
>>
>> It's intresting that with the prodrg topology of that mollecule ( with
>> worst charge distribution) I've never such problems. Might that error
>> be due to the wrong geometry parametrisation (e.g incorect dihedrals)
>> of the cGMP made by ATB ?
>>
>
> Simulate all components of your system separately and follow
> http://www.gromacs.org/Documentation/Terminology/Blowing_Up#Diagnosing_an_Unstable_System.
> Dihedrals should not be a major issue, since all of them can be adequately
> described by those already present in the parent force field.  Check against
> DGUA.
>
>
> -Justin
>
> --
> ========================================
>
> Justin A. Lemkul, Ph.D.
> Research Scientist
> 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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