Gmx pdb2gmx not working

GROMACS version:2020.4

first i’m sorry for asking many questions but i’m stuck in installtion and cannot move to work beacuse of it … i’m trying to test gromacs working or not by using

gmx pdb2gmx

but got

Required option was not provided, and the default file ‘protein’ does not
exist or is not accessible.
The following extensions were tried to complete the file name:
.gro, .g96, .pdb, .brk, .ent, .esp, .tpr

If you try to invoke pdb2gmx, it requires real arguments. If you want to test your installation, work through a real tutorial.

1 Like

Thanks for replyig , i will search but execuse me if you please can you help in this

the command is running well without gpu and i want to enforce gpu but facing problem