[gmx-users] grompp - Group protein not found

[Lara Bunte]

Hi

I create a file pr.mdp for equilibrating the water around my molecule and used after that the command

grompp -f pr.mdp -p topol.top -c em.gro -o pr.tpr

And I got tthe error:

Fatal error:
Group protein not found in index file.
Group names must match either [moleculetype] names
or custom index group names,in which case you
must supply an index file to the '-n' option of grompp.

Could you explain that error to me please? How to fix it?

Greetings
Lara