[gmx-users] Error_message

[Chris Neale]

>define = -DFLEX_SPC ; Use Fergusons Flexible water model [5]

That is not something that I am familiar with. Could you be including a corrupted section of .itp? It's not clear to me why
that would cause the problem that you outline here, but it's a place to start.

Also is your .mdp file in dos format?

To debug this, start with this:

touch empty.mdp
grompp -f empty.mdp ....
cp mdout.mdp correct.mdp
{edit correct.mdp values one at a time, e.g. change integrator from md to steep}
grompp -f correct.mdp ...

If that works, then try to figure out what the problem was.
Also, you can try adding in the options that you are having difficulty with one at a time to an otherwise empty mdp file.

Also, please make the title more descriptive next time you start a post.