darre...@ece.ubc.ca wrote:
Dear All,
I have been trying to determine why I am experiencing problems when I run
a gromacs file through x2top. I have checked my gromacs file with VMD to
ensure that the file is correct and VMD validates that my file is
correct as I see the intended structure. Thus, the atoms are indeed
located within reasonable distance from each other such that x2top
should be recognizing the bonds.
Here is an extract from my gromacs file:
2Grph C 1 0.000 0.000 0.000 0.0000 0.0000 0.0000
2Grph C 2 0.071 -0.123 0.000 0.0000 0.0000 0.0000
2Grph C 3 0.071 0.123 0.000 0.0000 0.0000 0.0000
2Grph C 4 -0.142 0.000 0.000 0.0000 0.0000 0.0000
2Grph C 5 -0.000 -0.250 0.000 0.0000 0.0000 0.0000
2Grph C 6 0.210 -0.120 0.000 0.0000 0.0000 0.0000
I thought that in order to make x2top work correctly that I would have to
modify the files as described in Christopher Stiles website
(http://cs86.com/CNSE/SWNT.htm). I made the specified changes to the
following files and saved them in my working directory:
ffencadv.n2t
ffgmx.n2t
ffgmxbon.itp
I also changed the name of ffgmxbon.itp to ffencadvbon.itp as I read in
one post that this file should be renamed as such.
After all these changes, I still experience a problem when I run the
command:
x2top -ff select -f graphene_nm.gro -o graphene_nm.top
selecting option 7: Encad all-atom force field, using scaled-down vacuum
charges
When I run the above command, I receive output telling me that the atoms
have 0 bonds. An extract of the output appears below for your reference.
Can not find forcefield for atom H-266 with 0 bonds
Can not find forcefield for atom H-267 with 0 bonds
Can not find forcefield for atom H-268 with 0 bonds
Can not find forcefield for atom H-269 with 0 bonds
Can not find forcefield for atom H-270 with 0 bonds
Could there still be an error in your gro file, as it seems to contain
only C, and the error message points to H. x2top might work slightly
better in 4.0.x. And by the way, this tutorial may be slightly
confusing. The only thing you need to do is edit the .n2t file
corresponding to your force field. I don't recall what is supplied in
3.3, but in 4.0 it is ffoplsaa.n2t.
-------------------------------------------------------
Program x2top, VERSION 3.3.3
Source code file: x2top.c, line: 206
Fatal error:
Could only find a forcefield type for 0 out of 270 atoms
-------------------------------------------------------
Could you please help me resolve this issue?
Thank you in advance for your assistance.
Darrell Koskinen
_______________________________________________
gmx-users mailing list gmx-users@gromacs.org
http://www.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-requ...@gromacs.org.
Can't post? Read http://www.gromacs.org/mailing_lists/users.php
--
David.
________________________________________________________________________
David van der Spoel, PhD, Professor of Biology
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596, 75124 Uppsala, Sweden
phone: 46 18 471 4205 fax: 46 18 511 755
sp...@xray.bmc.uu.se sp...@gromacs.org http://folding.bmc.uu.se
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
_______________________________________________
gmx-users mailing list gmx-users@gromacs.org
http://www.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-requ...@gromacs.org.
Can't post? Read http://www.gromacs.org/mailing_lists/users.php
