[gmx-users] Unable to generate .rtp file from gro and pdb file.

Mark Abraham mark.j.abraham at gmail.com
Wed Nov 14 05:29:28 CET 2018


Hi,

Your topology had 5 GEL and 2 PE, which means you have 7 things that could
be a problem. Start with 1 so you find out where the problem is.

Mark

On Mon, Nov 12, 2018 at 10:40 PM Karpurmanjari Kakati <
ch18resch01002 at iith.ac.in> wrote:

> Hi,
> I didn't understand, what you exactly meant. Could you be more elaborate?
>
> Karpurmanjari
>
> On Sun, Nov 11, 2018 at 12:37 PM Karpurmanjari Kakati <
> ch18resch01002 at iith.ac.in> wrote:
>
> > Hi
> > I tried doing the same, like you said.
> > 1. Copied the OPLS AA force field files to the directory, where my pdb
> > files were present.
> > 2. Modified the rtp file. but the error comes up in the pdb2gmx "no
> > residjue type in the residue database. "
> > Alternatively, what I tired doing is the following:
> >
> > 1. I constructed the polymer in Avogrado software.
> > 2. Used OBGMX to make the itp file. But the charge column genereated by
> > OBGMX is 0000.
> > 3. To include charge, I went back to Avogrado, and took the charges from
> > each atom and included it in the itp file by replacing the 0000  against
> > each atom.
> > 4. Now my topology file looks something like this:
> >
> >
> >
> > #include "oplsaa.ff/forcefield.itp"
> >
> >
> >
> > [ atomtypes ]
> > ; name1 name2   mass     charge  ptype   sigma   epsilon
> > N_3      N_3        14.0067      0.227    A      0.3261       0.2889
> > C_3      C_3        12.0107      0.050   A      0.3431       0.4396
> > C_2      C_2        12.0107      0.261  A      0.3431       0.4396
> > O_2      O_2        15.9994      -0.013   A      0.3118       0.2512
> > N_2      N_2        14.0067      -0.302   A      0.3261       0.2889
> > N_R      N_R        14.0067      -0.289   A      0.3261       0.2889
> > O_3      O_3        15.9994      -0.390    A      0.3118       0.2512
> > H_       H_          1.0079      0.200  A      0.2571       0.1842
> > NE      NE        14.0067      0.227   A      0.3261       0.2889
> > NH1      NH1        14.0067      0.227   A      0.3261       0.2889
> > NH2      NH2        14.0067      0.227   A      0.3261       0.2889
> >
> > CA      CA        12.0107      0.050   A      0.3431       0.4396
> > C      C        12.0107      0.050  A      0.3431       0.4396
> > CB      CB        12.0107      0.261   A      0.3431       0.4396
> > CG      CG        12.0107      0.261   A      0.3431       0.4396
> > CD      CD        12.0107     0.261   A      0.3431       0.4396
> > CZ      CZ        12.0107      0.261   A      0.3431       0.4396
> > N       N        14.0067      0.227    A      0.3261       0.2889
> > H1       H1          1.0079      0.200   A      0.2571       0.1842
> > H2       H2          1.0079      0.200   A      0.2571       0.1842
> > HA       HA          1.0079     0.200   A      0.2571       0.1842
> > HB1       HB1          1.0079      0.200   A      0.2571       0.1842
> > HB2       HB2          1.0079      0.200   A      0.2571       0.1842
> > HB3       HB3          1.0079      0.200   A      0.2571       0.1842
> > H       H          1.0079      0.200   A      0.2571       0.1842
> > HA1       HA1          1.0079      0.200   A      0.2571       0.1842
> > HA2       HA2          1.0079      0.200   A      0.2571       0.1842
> > HG1       HG1          1.0079      0.200   A      0.2571       0.1842
> > HG2       HG2          1.0079      0.200   A      0.2571       0.1842
> > HD1       HD1          1.0079      0.200   A      0.2571       0.1842
> > HD2       HD2          1.0079      0.200   A      0.2571       0.1842
> > HE       HE          1.0079      0.200   A      0.2571       0.1842
> > HH21       HH21          1.0079      0.200   A      0.2571       0.1842
> > HH22       HH22          1.0079      0.200   A      0.2571       0.1842
> > HH11       HH11          1.0079      0.200   A      0.2571       0.1842
> > HH12       HH12          1.0079      0.200   A      0.2571       0.1842
> > HG       HG          1.0079      0.200   A      0.2571       0.1842
> > HD       HD          1.0079      0.200   A      0.2571       0.1842
> > HW1       HW1          1.0079     0.200   A      0.2571       0.1842
> > HW2      HW2          1.0079      0.200   A      0.2571       0.1842
> > O      O        15.9994     -0.390   A      0.3118       0.2512
> >
> >
> >
> > #include <ge.itp>
> >
> > ; Include Position restraint file
> > #ifdef POSRES
> > #include "posre-gel.itp"
> > #endif
> >
> > #include <peg.itp>
> >
> > ; Include Position restraint file
> > #ifdef POSRES
> > #include "posre-pe.itp"
> > #endif
> >
> > [ system ]
> > GEL and PE
> >
> > [ molecules ]
> > GEL      5
> > PE       2
> >
> >
> >
> > And now I am performing EM in vacuum for the system. The error comes to
> be
> > it stops Energy minimization before the desired energy is reached.
> > Like I read from other error mails, it says the topology or the itp file
> > had defects.
> >
> >
> > My query is, I just added charges to the itp file generated from OBGMX.
> > Is that the reason why my energy minimization is stopping at the middle.
> >
> > Kindly help with this.
> >
> >
> > Karpurmanjari
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > On Mon, Nov 5, 2018 at 10:46 PM Karpurmanjari Kakati <
> > ch18resch01002 at iith.ac.in> wrote:
> >
> >> Dear Justin,
> >>
> >> I want to add the residue "hydroxyproline" or "HYP" in the OPLS AA in
> the
> >> aminoacids.rtp file . I have all the files of OPLS AA force field in my
> >> working directory.
> >> For that I tried to generate the initial rtp format file from the
> hydroxy
> >> proline's .pdb and .gro  files using the following command:
> >> gmx x2top  -f hyd.gro  -r hyd.rtp  -pbc -ff oplsaa
> >>
> >> and I got the following error:
> >>
> >> Opening force field file
> >> /usr/share/gromacs/top/oplsaa.ff/atomname2type.n2t
> >> There are 23 name to type translations in file oplsaa.ff
> >> Generating bonds from distances...
> >> atom 18
> >> Can not find forcefield for atom CA-2 with 4 bonds
> >> Can not find forcefield for atom C-3 with 3 bonds
> >> Can not find forcefield for atom CD-7 with 4 bonds
> >>
> >> -------------------------------------------------------
> >> Program:     gmx x2top, version 2018.1
> >> Source file: src/gromacs/gmxpreprocess/x2top.cpp (line 205)
> >>
> >> Fatal error:
> >> Could only find a forcefield type for 15 out of 18 atoms.
> >>
> >>
> >> Can you help me with this.
> >>
> >> I want to add this residue to the rtp file so that I can use the step
> >> pdb2gmx directly.
> >>
> >>
> >> Aijoni
> >>
> >>
> >>
> >>
> --
> Gromacs Users mailing list
>
> * Please search the archive at
> http://www.gromacs.org/Support/Mailing_Lists/GMX-Users_List before
> posting!
>
> * Can't post? Read http://www.gromacs.org/Support/Mailing_Lists
>
> * For (un)subscribe requests visit
> https://maillist.sys.kth.se/mailman/listinfo/gromacs.org_gmx-users or
> send a mail to gmx-users-request at gromacs.org.
>


More information about the gromacs.org_gmx-users mailing list