[gmx-users] Using CHARMM36 in GROMACS to simulate polysaccharides

Justin Lemkul jalemkul at vt.edu
Tue Jul 11 19:04:14 CEST 2017



On 7/11/17 2:46 AM, Akash Ranjan wrote:
> Sir,
> 
> I am facing difficulty in making topology for a simple molecule using CHARMM36 
> but i am facing certain difficulty in that such as
> 
> (a)Warning: Long Bond (3-10 = 0.566378 nm)
> Warning: Long Bond (3-4 = 0.426475 nm)
> Warning: Long Bond (4-16 = 0.59 nm)
> Warning: Long Bond (4-11 = 0.671583 nm)
> Warning: Long Bond (5-6 = 0.428864 nm)
> Warning: Short Bond (5-7 = 0.044 nm)
> Warning: Long Bond (7-8 = 0.648229 nm)
> Warning: Long Bond (8-20 = 0.539527 nm)
> Warning: Long Bond (9-21 = 0.849567 nm)
> Warning: Long Bond (10-22 = 0.584145 nm)
> Warning: Long Bond (11-23 = 0.637749 nm)
> 
> 
> (b)
> ERROR 4 [file topol.top, line 76]:
>    No default Bond types
> 
> 
> 
> 
> ERROR 7 [file topol.top, line 169]:
>    No default U-B types
> 
> 
> ERROR 19 [file topol.top, line 202]:
>    No default Proper Dih. types
> 

The missing parameters mean your atom type assignments are incorrect.

> Here is mine rtp enteries.can you suggest me how to correct t?
> 
> 
> [ UNK ]
>    [ atoms ]
>             C1 CC3161   12.01100 1
>             C2 CC3161   12.01100 2
>             C3 CC3161   12.01100 3
>             C4 CC3162   12.01100 4
>             C5 CC3163   12.01100 5
>             O6 OC3C61   -0.400   6
>             C7 CC3161   12.01100 7
>             O8 OC311    -0.650   8
>             O9 OC311    -0.650   9
>            O10 OC311    -0.650   10
>            O11 OC311    -0.650   11
>            O12 OC311    -0.650   12
>            H13 HCA1     1.00800  13
>            H14 HCA1     1.00800  14
>            H15 HCA1     1.00800  15
>            H16 HCA1     1.00800  16
>            H17 HCA1     1.00800  17
>            H18 HCA1     1.00800  18
>            H19 HCA1     1.00800  19
>            H20 HX       0.090    20
>            H21 HX       0.090    21
>            H22 HX       0.090    22
>            H23 HX       0.090    23
>            H24 HX       0.090    24
> 

You have a mix of charges and masses in the column that should only be charges, 
so this is a fundamentally broken entry.

> 
>    [ bonds ]
>             C1    H13
>             C1    O12
>             C1    C5
>             C1    C2
>             C2    H14
>             C2    O9
>             C2    C3
>             C3    H15
>             C3    O10
>             C3    C4
>             C4    H16
>             C4    O11
>             C4    O6
>             C5    O6
>             C5    C7
>             C5    H17
>             C7    H18
>             C7    H19
>             C7    O8
>             O8    H20
>             O9    H21
>             O10   H22
>             O11   H23
>             O12   H24
> 
> PDB file:-
> 

Have you visualized these coordinates?  The format is totally broken so this is 
what pdb2gmx is complaining about.  The structure is complete nonsense.

-Justin

> HEADER    PROTEIN                                 06-JUL-17   NONE
> TITLE     NULL
> COMPND    MOLECULE: ads1.mol
> SOURCE    NULL
> KEYWDS    NULL
> EXPDTA    NULL
> AUTHOR    Marvin
> ATOM      1  C1   UNK     0       2.462  -3.244   0.792  1.00  0.00           C
> ATOM      2  C2   UNK     0       2.766  -4.727   0.446  1.00  0.00           C
> ATOM      3  C3   UNK     0       1.464  -5.574   0.403  1.00  0.00           C
> ATOM      4  C4   UNK     0       0.378  -4.893  -0.473  1.00  0.00           C
> ATOM      5  C5   UNK     0       1.343  -2.682  -0.137  1.00  0.00           C
> ATOM      6  O6   UNK     0       0.167  -3.523  -0.076  1.00  0.00           O
> ATOM      7  C7   UNK     0       0.903  -1.252   0.257  1.00  0.00           C
> ATOM      8  O8   UNK     0      -0.118  -0.796  -0.628  1.00  0.00           O
> ATOM      9  O9   UNK     0       3.663  -5.266   1.418  1.00  0.00           O
> ATOM     10  O10  UNK     0       1.748  -6.880  -0.095  1.00  0.00           O
> ATOM     11  O11  UNK     0       0.692  -4.976  -1.864  1.00  0.00           O
> ATOM     12  O12  UNK     0       3.652  -2.465   0.678  1.00  0.00           O
> HETATM   13  H13  UNK     0       2.111  -3.189   1.801  1.00  0.00           H
> HETATM   14  H14  UNK     0       3.215  -4.763  -0.524  1.00  0.00           H
> HETATM   15  H15  UNK     0       1.084  -5.651   1.400  1.00  0.00           H
> HETATM   16  H16  UNK     0      -0.535  -5.428  -0.314  1.00  0.00           H
> HETATM   17  H17  UNK     0       1.761  -2.663  -1.122  1.00  0.00           H
> HETATM   18  H18  UNK     0       1.744  -0.593   0.198  1.00  0.00           H
> HETATM   19  H19  UNK     0       0.522  -1.264   1.257  1.00  0.00           H
> HETATM   20  H20  UNK     0       0.223  -0.784  -1.536  1.00  0.00           H
> HETATM   21  H21  UNK     0       3.249  -5.230   2.295  1.00  0.00           H
> HETATM   22  H22  UNK     0       2.093  -6.813  -0.999  1.00  0.00           H
> HETATM   23  H23  UNK     0       1.518  -4.498  -2.038  1.00  0.00           H
> HETATM   24  H24  UNK     0       3.980  -2.507  -0.234  1.00  0.00           H
> CONECT    1    2    5   12   13
> CONECT    2    1    3    9   14
> CONECT    3    2    4   10   15
> CONECT    4    3    6   11   16
> CONECT    5    1    6    7   17
> CONECT    6    4    5
> CONECT    7    5    8   18   19
> CONECT    8    7   20
> CONECT    9    2   21
> CONECT   10    3   22
> CONECT   11    4   23
> CONECT   12    1   24
> CONECT   13    1
> CONECT   14    2
> CONECT   15    3
> CONECT   16    4
> CONECT   17    5
> CONECT   18    7
> CONECT   19    7
> CONECT   20    8
> CONECT   21    9
> CONECT   22   10
> CONECT   23   11
> CONECT   24   12
> MASTER        0    0    0    0    0    0    0    0   24    0   24    0
> END
> 
> 
> Akash
> 
> Thanks
> 
> 

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

Justin A. Lemkul, Ph.D.
Ruth L. Kirschstein NRSA Postdoctoral Fellow

Department of Pharmaceutical Sciences
School of Pharmacy
Health Sciences Facility II, Room 629
University of Maryland, Baltimore
20 Penn St.
Baltimore, MD 21201

jalemkul at outerbanks.umaryland.edu | (410) 706-7441
http://mackerell.umaryland.edu/~jalemkul

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


More information about the gromacs.org_gmx-users mailing list