# Starting a REMD run

**URL:** <https://gromacs.bioexcel.eu/t/starting-a-remd-run/6440>\
**Category:** User discussions\
**Tags:** mdrun\
**Created:** [May 18, 2023, 6:13pm UTC](https://gromacs.bioexcel.eu/t/starting-a-remd-run/6440 "2023-05-18T18:13:31Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![ksr](https://avatars.discourse-cdn.com/v4/letter/k/d6d6ee/32.png) [@ksr](https://gromacs.bioexcel.eu/u/ksr)\
**Post date:** [May 18, 2023, 6:13pm UTC](https://gromacs.bioexcel.eu/t/starting-a-remd-run/6440/1 "2023-05-18T18:13:31Z")

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GROMACS version:2023  
GROMACS modification: No  
I have manually created a series of 16 .tpr files corresponding to 16 temperatures named IV\_0.tpr to IV\_15.tpr. I am trying to start a short simulation to test the acceptance ratios.

My machine is running: CPU: Intel Xeon Silver 4110 (32) processors

I have tried (based upon web searches)

gmx mdrun -s IV\_.tpr -multi 16 -replex 1000 -noappend  
which returns: filename IV\_.tpr does not exist

gmx mdrun -deffnm IV -multi 16 -replex 1000 -noappend  
which returns: unknown option -multi

gmx mdrun --deffnm -np 32 -replex 1000 -noappend  
which returns: unknown option -np

gmx mpirun -deffnm -np 32 -replex 1000 -noappend  
which returns: mpirun is not a GROMACS command

What is a viable mdrun command to start a remd simulation in this case?

Best,

Ken