[gmx-users] Diagnosing + system blowing up

Shima Arasteh shima_arasteh2001 at yahoo.com
Mon Jul 30 23:16:54 CEST 2012


Wow!  That was a fabulous explanation given to me. Thanks dear Mark! :-)

I regenerated the topol.top to check the correctness of input and FF files. Some output has been changed however a little bit. Now, I bring you all was needed again:

> 1. rtp entry
>
>[ FVAL ]
 [ atoms ]
    CN    C     0.357    0
    ON    O    -0.51    1
    H1    HA    0.100    2
    N    NH1    -0.423    3
    HN    H    0.333    4
    CA    CT1    0.034    5
    HA    HB    0.09    6
    CB    CT1    -0.093    7
    HB    HA    0.09    8
    CG1    CT3    -0.268    9
    HG11    HA    0.09    10
    HG12    HA    0.09    11
    HG13    HA    0.09    12
    CG2    CT3    -0.268    13
    HG21    HA    0.09    14
    HG22    HA    0.09    15
    HG23    HA    0.09    16
    C    C    0.528    17
    O    O    -0.510    18
 [ bonds ]
    CN    H1
    CN    ON
    CN    N
    N    HN
    CA    N
    CA    HA
    CA    C
    C    O
    CA    CB
    CB    HB
    CB    CG1
    CB    CG2
    CG2    HG21
    CG2    HG22
    CG2    HG23
    CG1    HG11
    CG1    HG12
    CG1    HG13
     
 [ impropers ]
    CN     N    ON    H1

> 2. hdb entry

In which file?
*aminoacids.hdb


> FVAL    6
> 1    1    H1    CN    N    ON

This should be generating H1 bonded to CN...

> 1    1    HN    N    C    CA
> 1    5    HA    CA    N    C    CB
> 1    5    HB    CB    CA    CG1    CG2
> 3    4    HG1    CG1    CB    CA
> 3    4    HG2    CG2    CB    CA
>
> 3. N-terminal fragment
> HETATM    1  CN  FVAL    1      -0.721   1.600   1.249
> HETATM    2  ON  FVAL    1      -0.839   2.806   1.453
> ATOM      3  N   FVAL    1      -1.227   0.728   2.125
> ATOM      4  CA  FVAL    1      -1.918   1.159   3.323
> ATOM      5  C   FVAL    1      -1.969   2.678   3.410
> ATOM      6  O   FVAL    1      -0.931   3.335   3.447
> ATOM      7  CB  FVAL    1      -1.219   0.644   4.576
> ATOM      8  CG1 FVAL    1       0.208   1.178   4.618
> ATOM      9  CG2 FVAL    1      -1.976   1.118   5.812
>
> 4. pdb2gmx command
> #pdb2gmx -f monomer.pdb -o monomer.gro -water tip3p -ter
>
> 5. pdb2gmx output

Using the Charmm36-modified force field in directory ./charmm36-modified.ff

Opening force field file ./charmm36-modified.ff/aminoacids.r2b
Opening force field file ./charmm36-modified.ff/rna.r2b
Reading monomer.pdb...
Read 177 atoms
Analyzing pdb file
Splitting chemical chains based on TER records or chain id changing.
There are 1 chains and 0 blocks of water and 24 residues with 177 atoms

  chain  #res #atoms
  1 ' '    24    177  

All occupancy fields zero. This is probably not an X-Ray structure
Opening force field file ./charmm36-modified.ff/atomtypes.atp
Atomtype 1
Reading residue database... (charmm36-modified)
Opening force field file ./charmm36-modified.ff/aminoacids.rtp
Residue 42
Sorting it all out...
Opening force field file ./charmm36-modified.ff/dna.rtp
Residue 46
Sorting it all out...
Opening force field file ./charmm36-modified.ff/lipids.rtp
Residue 82
Sorting it all out...
Opening force field file ./charmm36-modified.ff/rna.rtp
Residue 86
Sorting it all out...
Opening force field file ./charmm36-modified.ff/aminoacids.hdb
Opening force field file ./charmm36-modified.ff/dna.hdb
Opening force field file ./charmm36-modified.ff/lipids.hdb
Opening force field file ./charmm36-modified.ff/rna.hdb
Opening force field file ./charmm36-modified.ff/aminoacids.n.tdb
Opening force field file ./charmm36-modified.ff/dna.n.tdb
Opening force field file ./charmm36-modified.ff/rna.n.tdb
Opening force field file ./charmm36-modified.ff/aminoacids.c.tdb
Opening force field file ./charmm36-modified.ff/dna.c.tdb
Opening force field file ./charmm36-modified.ff/rna.c.tdb

Back Off! I just backed up topol.top to ./#topol.top.2#
Processing chain 1 (177 atoms, 24 residues)
Identified residue FVAL1 as a starting terminus.
Identified residue GLY24 as a ending terminus.
8 out of 8 lines of specbond.dat converted successfully
Select start terminus type for FVAL-1
 0: NH3+
 1: NH2
 2: None
2
Start terminus FVAL-1: None
Select end terminus type for GLY-24
 0: COO-
 1: COOH
 2: CT2
 3: CT3
 4: None
0
End terminus GLY-24: COO-
Opening force field file ./charmm36-modified.ff/aminoacids.arn
Opening force field file ./charmm36-modified.ff/dna.arn
Opening force field file ./charmm36-modified.ff/rna.arn
Checking for duplicate atoms....
Now there are 24 residues with 360 atoms
Making bonds...
Number of bonds was 362, now 362
Generating angles, dihedrals and pairs...
Before cleaning: 925 pairs
Before cleaning: 930 dihedrals
Keeping all generated dihedrals
Making cmap torsions...There are   22 cmap torsion pairs
There are  930 dihedrals,   49 impropers,  644 angles
           916 pairs,      362 bonds and     0 virtual sites
Total mass 2510.906 a.m.u.
Total charge 1.000 e
Writing topology

Back Off! I just backed up posre.itp to ./#posre.itp.1#

Writing coordinate file...

Back Off! I just backed up monomer.gro to ./#monomer.gro.1#
                --------- PLEASE NOTE ------------
You have successfully generated a topology from: monomer.pdb.
The Charmm36-modified force field and the tip3p water model are used.
                --------- ETON ESAELP ------------


> 6. N-terminal fragment of the grompp -c input
    1FVAL    CN    1   3.039   1.904   2.416
    1FVAL    H1    2   3.086   1.871   2.334
    1FVAL    ON    3   3.027   2.025   2.436
    1FVAL     N    4   2.988   1.817   2.504
    1FVAL    HN    5   3.029   1.759   2.433
    1FVAL    CA    6   2.919   1.860   2.623
    1FVAL    HA    7   2.828   1.821   2.614
    1FVAL    CB    8   2.989   1.808   2.749
    1FVAL    HB    9   2.991   1.708   2.747
    1FVAL   CG1   10   3.132   1.862   2.753
    1FVAL  HG11   11   3.178   1.828   2.835
    1FVAL  HG12   12   3.181   1.831   2.672
    1FVAL  HG13   13   3.130   1.962   2.754
    1FVAL   CG2   14   2.913   1.856   2.872
    1FVAL  HG21   15   2.959   1.822   2.954
    1FVAL  HG22   16   2.911   1.956   2.874
    1FVAL  HG23   17   2.820   1.821   2.869
    1FVAL     C   18   2.914   2.012   2.632
    1FVAL     O   19   3.018   2.077   2.636

... and this shows atom H1 around 0.1nm from atom C. I can think of no 
legitimate reason how this could occur, given your stated .hdb, but I 
seem to recall an old .hdb version you showed had a line

1    1    H1    C    N    ON

rather than the correct

1    1    H1    CN    N    ON

********* I checked it, there was the correct one.

and this would explain the weird H1 position perfectly (but not how it still gets bonded to atom 1). I'd like you to double check that ./charmm36-modified.ff/aminoacids.hdb has (only) the correct FVAL entry. Also, I'd like to see the first 30 or so lines of the [bonds] section of this [moleculetype] in topol.top, so we can really see what bonds are generated.

* First 50 lines of the [bonds] section:

[ bonds ]
;  ai    aj funct            c0            c1            c2            c3
    1     2     1 
    1     3     1 
    1     4     1 
    4     5     1 
    4     6     1 
    6     7     1 
    6     8     1 
    6    18     1 
    8     9     1 
    8    10     1 
    8    14     1 
   10    11     1 
   10    12     1 
   10    13     1 
   14    15     1 
   14    16     1 
   14    17     1 
   18    19     1 
   20    21     1 
   20    22     1 
   22    23     1 
   22    24     1 
   22    29     1 
   24    25     1 
   24    26     1 
   24    27     1 
   27    28     1 
   29    30     1 
   29    31     1 
   31    32     1 
   31    33     1 
   33    34     1 
   33    35     1 
   33    48     1 
   35    36     1 
   35    37     1 
   35    38     1 
   38    39     1 
   38    40     1 
   38    44     1 
   40    41     1 
   40    42     1 
   40    43     1 
   44    45     1 
   44    46     1 
   44    47     1 
   48    49     1 
   48    50     1 
   50    51     1 
   50    52     1 


I think you may have encountered a new bug in pdb2gmx.

>      1FVAL     O   19   3.019   2.076   2.635
>
> 7.grompp command line
> # grompp -f ions.mdp -c monomer_solv.gro -p topol.top -o ions.tpr
>
>
> 8. grompp output
> Generated 21528 of the 21528 non-bonded parameter combinations
> Generating 1-4 interactions: fudge = 1
> Generated 18355 of the 21528 1-4 parameter combinations
>
> ERROR 1 [file topol.top, line 414]:
>    No default Bond types
>
>
> ERROR 2 [file topol.top, line 1698]:
>    No default U-B types
>
>
> ERROR 3 [file topol.top, line 1699]:
>    No default U-B types
>
>
> ERROR 4 [file topol.top, line 2345]:
>    No default Proper Dih. types
>
>

> ERROR 5 [file topol.top, line 2346]:
>    No default Proper Dih. types
>
> ERROR 6 [file topol.top, line 3278]:
>    No default Improper Dih. types

All this probably follows on from the confused state of bonding to H1, 
e.g. if CN-H1 is defined from the .rtp bond, and there's now a C-H1 from 
the possibly erroneous .hdb construction. What is line 414 of topol.top?

* line 414 of topol.tp:
    [bonds]
       1     2     1 




>
> Excluding 3 bonded neighbours molecule type 'Protein'
> Excluding 2 bonded neighbours molecule type 'SOL'
>
> NOTE 1 [file topol.top, line 3378]:
>    System has non-zero total charge: 1.000000
>    Total charge should normally be an integer. See
>    http://www.gromacs.org/Documentation/Floating_Point_Arithmetic
>    for discussion on how close it should be to an integer.
>    
>
>
>
> There was 1 note
>
> -------------------------------------------------------
> Program grompp, VERSION 4.5.5
> Source code file: /home/abuild/rpmbuild/BUILD/gromacs-4.5.5/src/kernel/grompp.c, line: 1372
>
> Fatal error:
> There were 6 errors in input file(s)
> For more information and tips for troubleshooting, please check the GROMACS
> website at http://www.gromacs.org/Documentation/Errors
>
>



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