On 10/3/12 10:03 AM, Elie M wrote:

Hello Emanuel.
First of all thank you for your help. I am sorry if my previous e-mail was a 
bit confusing.  I will tell what I did recently.
(1) I removed all the information :molecule type, atoms, bond....dihedral from my 
top file and pasted them to the ipt file , the one I called ffoplsaamod.itp; I also 
included an "#include command# referring to the .itp file. so my top file now 
just looks like that:
"

That doesn't really make any sense. You've chopped out the information for your molecule from the topology that g_x2top wrote, then simply re-included that information? The output of g_x2top should be a functional topology; you should not have to adjust it. If you need this topology to be an .itp file, i.e. as a ligand in some other .top, then you only need to make small adjustments. See the following:

http://www.gromacs.org/Documentation/File_Formats/.itp_File

;;      File 'S54.top' was generated;   By user: User (1000);   On host: User-PC;       At 
date: Wed Sep 26 01:43:14 2012;;     This is your include topology file;     Generated by 
x2top;#include "ffoplsaamod.itp"  "
and my foplsaamod.itp has the info that was present in .top file i.e:
"[ moleculetype ]

; Name            nrexcl

S54NS               3



[ atoms ]

;   nr
type  resnr residue  atom
cgnr     charge       mass
typeB    chargeB      massB

      1
opls_145      1    LIG
C      1          0
12.011   ; qtot 0

      2
opls_735      1    LIG
C      2          0
12.011   ; qtot 0

      3
opls_734      1    LIG
S      3          0
32.06   ; qtot 0

      4
opls_735      1    LIG
C      4          0
12.011   ; qtot 0

      5
opls_145      1
LIG      C      5
0     12.011   ; qtot 0

      6
opls_145      1    LIG
C      6          0
12.011   ; qtot 0

      7
opls_516      1    LIG
C      7          0
12.011   ; qtot 0

      8
opls_516      1    LIG
C      8          0
12.011   ; qtot 0....[ bonds ]...37    36
42    83     1

    35
37    38    39
1

    37
38    39    40
1

    38
39    40    36
1

    36
40    46    92
1


I don't know whether it is your email client or the topology itself, but the seemingly random line breaks make these posts very difficult to read.



[ system ]

; Name

S54NS



[ molecules ]

; Compound        #mols

S54NS               1

  "Have I missed something? i guess I did. I am getting an error of the form 
(when executing grompp_:
Invalid order for directive [atoms].
(2) What about the ffoplsaabon.itp and ffoplsaanb.itp files? Do they have to be 
put somewhere.
I am sorry to bombard u with all of this but I have got my head spinning 
thinking about topologies and fixing this error.


A topology follows a defined structure that must be observed. The hierarchy is described in the manual, but can be distilled into the following requirements:

1. You must #include a force field that defines all default elements (i.e. a [defaults] directive) that govern how the force field operates.

2. You must #include the nonbonded and bonded parameters for that force field, in that order. Bonded parameters are assigned based on atom types, which must be declared first in order to be used.

3. After all force field-level parameters (items 1 and 2), you can introduce molecules that use these parameters. This is the point where you can proceed to [atoms], [bonds], etc for a particular molecule.

-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

========================================
--
gmx-users mailing list    gmx-users@gromacs.org
http://lists.gromacs.org/mailman/listinfo/gmx-users
* Please search the archive at 
http://www.gromacs.org/Support/Mailing_Lists/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/Support/Mailing_Lists

Reply via email to