Can't open tpr file

User discussions
1

Dear users,
I use 4.6.5 Gromacs. I have simulated dppc bilayer lipid and for the md part, I used grompp like below:

grompp -f md.mdp -c dppcnpt.gro -p topol.top -maxwarn 10 
    mdrun -v -c dppcmd.gro

in this way, md.tpr and md.xtc aren’t made. but for analyzing my bilayer I need both of these files. so I wrote
trjconv -f traj.trr -o md.tpr
but when I wanted to index some atoms I got this error:
can’t open md.tpr

Does anyone help me?
Best,
Shiva

2

Please note that this is an ancient version of GROMACS that is no longer supported.

Your grompp command does not specify an output file, so it will not be called md.tpr, it will be called topol.tpr. You should also NEVER be setting -maxwarn 10, or really using -maxwarn at all. You can be bypassing critically important problems that lead to instability or invalid simulations.

If mdrun did not produce output, it should have failed with a clear error that will appear in the .log file. There’s no point trying to do anything with trjconv if none of those files exist.

3

Thanks alot. your information was so useful. so I think it is better that I update my Gromacs to the other version and after that, I continue. do you think 5.1.4 Gromacs is good enough?

4

You should always use the newest version of GROMACS available for any kind of new work. The 5.1 series is also deprecated, as is the 2016 and maybe 2018 series. Don’t bother with ancient code, make use of the newest features, bug fixes, and performance enhancements.

5

Thanks a lot. ok, I will install the newest version.