[gmx-users] error with changing pdb file

Justin A. Lemkul jalemkul at vt.edu
Fri Dec 18 19:30:17 CET 2009



ksm tprk wrote:
> Hi Justin,
> 
> I will try to be more clear. What I did, first I created a carbon 
> nanotube using Tubegen carbon nanotube generator. After that I changed 
> one carbon atom with another atom using text editor.
> My ffgmx file is same as what http://cs86.com/CNSE/SWNT.htm has.
> Next I created .top by applying ffgmx.n2t force field and .gro file 
> respectively. And I used grompp to run my simulation. And What I got the 
> error is:
> 

OK, the problem is pretty straightforward now.  You have a nitrogen atom within 
a CNT, and there are no suitable angle parameters for such a system.  The atom 
type chosen is simply "N," which (from the ffgmx.atp file) corresponds to a 
peptide nitrogen in an amide, which is not what is present in your system so 
this assignment is incorrect.  Perhaps "NR6" might be more appropriate?

-Justin

> creating statusfile for 8 nodes...
> 
> Back Off! I just backed up mdout.mdp to ./#mdout.mdp.3#
> checking input for internal consistency...
> calling cpp...
> processing topology...
> Generated 1282 of the 1485 non-bonded parameter combinations
> WARNING 1 [file "cnt80.top", line 11144]:
>   No default Angle types, using zeroes
> WARNING 2 [file "cnt80.top", line 11144]:
>   No default Angle types for perturbed atoms, using normal values
> WARNING 3 [file "cnt80.top", line 11145]:
>   No default Angle types, using zeroes
> WARNING 4 [file "cnt80.top", line 11145]:
>   No default Angle types for perturbed atoms, using normal values
> WARNING 5 [file "cnt80.top", line 11187]:
>   No default Angle types, using zeroes
> WARNING 6 [file "cnt80.top", line 11187]:
>   No default Angle types for perturbed atoms, using normal values
> WARNING 7 [file "cnt80.top", line 11189]:
>   No default Angle types, using zeroes
> WARNING 8 [file "cnt80.top", line 11189]:
>   No default Angle types for perturbed atoms, using normal values
> WARNING 9 [file "cnt80.top", line 11190]:
>   No default Angle types, using zeroes
> WARNING 10 [file "cnt80.top", line 11190]:
>   No default Angle types for perturbed atoms, using normal values
> Cleaning up temporary file grompp5QOA9q
> -------------------------------------------------------
> Program grompp_mpi, VERSION 3.3.1
> Source code file: fatal.c, line: 416
> 
> 
> 
> 
> The error atom is 25th atom. and the error lines specified in topology 
> file are( I underlined and made bold them):
> 
> .....
> [ angles ]             
> ;  ai    aj    ak funct            c0            c1            c2       
>      c3
>     2     1    20     1
>     1     2     3     1
>     2     3     4     1
>     2     3    22     1
>     4     3    22     1
>     3     4     5     1
>  *   3     4    25     1*
> *    5     4    25     1*
> *   * 4     5     6     1
>     5     6     7     1
>     6     7     8     1
>     6     7    26     1
>     8     7    26     1
>     7     8     9     1
>     7     8    29     1
>     9     8    29     1
>     8     9    10     1
>     9    10    11     1
>    10    11    12     1
>    10    11    30     1
>    12    11    30     1
>    11    12    13     1
>    11    12    33     1
>    13    12    33     1
>    12    13    14     1
>    13    14    15     1
>    14    15    16     1
>    14    15    34     1
>    16    15    34     1
>    15    16    17     1
>    15    16    37     1
>    17    16    37     1
>    16    17    18     1
>    17    18    19     1
>    18    19    20     1
>    18    19    38     1
>    20    19    38     1
>     1    20    19     1
>     1    20    21     1
>    19    20    21     1
>    20    21    22     1
>    20    21    40     1
>    22    21    40     1
>     3    22    21     1
>     3    22    23     1
>    21    22    23     1
>    22    23    24     1
>    22    23    42     1
>    24    23    42     1
>   * 23    24    25     1*
>    23    24    45     1
>    *25    24    45     1*
> *    4    25    24     1*
>     4    25    26     1
>    24    25    26     1
>     7    26    25     1
> .....
> 
> 
> 
> I attached topology and coordinate files too.
> I am sorry that I gave not enough information.
> 
> Thank you,
> Kasim
> 
> 
>  > I can't keep trying to help you if you don't provide relevant 
> information. If
>  > you want free help, you have to make it easy for those trying to help 
> you. This
>  > topology snippet is not at all what I asked to see. To be clear, 
> please post
>  > the following information:
>  >
>  > 1. The lines from the topology specified in the grompp error messages 
> (the line
>  > numbers are given in the error messages)
>  > 2. The coordinate file entries that correspond to the atoms on those 
> lines. It
>  > would be helpful to see the coordinate file that works, as well as 
> the one that
>  > was modified that no longer works.
>  >
>  > Going back to your very first post, the root of the problem is that 
> there are
>  > not bonded parameters in the ffgmx force field to describe whatever 
> changes you
>  > made. Since you have yet to actually demonstrate what these changes 
> were and
>  > how the affected the topology, there is no better help that anyone 
> can provide.
>  >
>  > -Justin
>  >
>  > --
>  > ========================================
>  >
>  > 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
>  >
>  > ========================================
>  > --
>  > gmx-users mailing list gmx-users at gromacs.org
>  > http://lists.gromacs.org/mailman/listinfo/gmx-users
>  > Please search the archive at http://www.gromacs.org/search before 
> posting!
>  > Please don't post (un)subscribe requests to the list. Use the
>  > www interface or send it to gmx-users-request at gromacs.org.
>  > Can't post? Read http://www.gromacs.org/mailing_lists/users.php
> 
> ------------------------------------------------------------------------
> Hotmail: Free, trusted and rich email service. Get it now. 
> <http://clk.atdmt.com/GBL/go/171222984/direct/01/>
> 

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

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

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



More information about the gromacs.org_gmx-users mailing list