[gmx-users] use AMBER ff03 force field in gromacs 4

[mircial at sjtu.edu.cn]

Dear All:

I am using GROMACS 4 to do MD simulations of protein-ligand  
complexes.I encountered some problems when generating the topology  
file of the ligands. I generate the topology file of ligands by using  
topolbuild package. The atom types of GAFF force field are assigned to  
the atoms of the ligand. However, when I used grompp command to write  
the tpr file. There is an error saying:

Fatal error:
Atomtype c3 not found
For more information and tips for troubleshooting, please check the GROMACS


It seemed that, the amber ff03 force field in gromacs 4 didn't include  
the atom types of the GAFF force field.

Does any one have ever encountered the same problem? What can I do to  
solve this problem?

Thanks in advance!!!

R.X.G.