I am working on molecular dynamics simulation in Gromacs. The output of the pdb2gmx is not working properly: only the .itp file and the .top file generate, not the .pdb/.gro files (output files).
what Mr. Kamberaj pointed is a good source. You can find a lot more in the link below. In general "pdb2gmx" should not create any problem. log file would give you a lot information. I hope you can fix it in no time. If persists let us know.