[gmx-users] grompp g96angle types error

Justin A. Lemkul jalemkul at vt.edu
Tue Jan 17 15:12:58 CET 2012

pithevenet at free.fr wrote:
> Dear all,
> I launch those commands for few models :
> pdb2gmx  -f 2it7-10_bestene1mc-SC.pdb  -o 2it7-10_bestene1mc-SC.gro  -p 2it7-10_bestene1mc-SC.top -ignh -missing
> editconf -f 2it7-10_bestene1mc-SC.gro -o 2it7-10_bestene1mc-SC-box.gro -d 2.0 -c -bt cubic
> grompp -c 2it7-10_bestene1mc-SC-box.gro -p 2it7-10_bestene1mc-SC.top -o 2it7-10_bestene1mc-SC-min.tpr -f 2it7-10_bestene1mc-SC-em.mdp
> and at the grompp command I obtain : 
> checking input for internal consistency...
> calling /lib/cpp...
> processing topology...
> Generated 165 of the 1596 non-bonded parameter combinations
> ERROR 0 [file "2it7-10_bestene1mc-SC.top", line 1242]:
>   No default G96Angle types
> Excluding 3 bonded neighbours for Protein 1
>   System has non-zero total charge: 1.000000e+00
> processing coordinates...
> double-checking input for internal consistency...
> renumbering atomtypes...
> converting bonded parameters...
> #   G96BONDS:   254
> #  G96ANGLES:   367
> #      PDIHS:   149
> #      IDIHS:   108
> #       LJ14:   436
> I don't understand the meaning of: No default G96Angle types.
> All my files are generated by the same way, with the same softwares, and the sames options. All the models are done by the same software so the .pdb file only the coordinates of the protein change for one model to another.
> Can you help me?

The error message indicates that angle parameters do not exist in the chosen 
force field for a certain sequence of atoms.  This would be highly unusual for a 
standard protein.  Are you using any custom residues?  The error message 
indicates the line in the .top that is causing the problem.  Look it up, find 
which atoms it corresponds to, and check ffbonded.itp to verify that suitable 
parameters are indeed not present.  If you're using some kind of custom residue 
or nonstandard composition of atoms, then you'll likely have to parameterize the 
missing term(s) yourself.



Justin A. Lemkul
Ph.D. Candidate
ICTAS Doctoral Scholar
Department of Biochemistry
Virginia Tech
Blacksburg, VA
jalemkul[at]vt.edu | (540) 231-9080


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