# Correct Setup for Temperature Replica Exchange (T-REMD) in GROMACS Without PLUMED

**URL:** <https://gromacs.bioexcel.eu/t/correct-setup-for-temperature-replica-exchange-t-remd-in-gromacs-without-plumed/11563>\
**Category:** User discussions\
**Tags:** replica-exchange\
**Created:** [February 15, 2025, 2:53pm UTC](https://gromacs.bioexcel.eu/t/correct-setup-for-temperature-replica-exchange-t-remd-in-gromacs-without-plumed/11563 "2025-02-15T14:53:43Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![b-omics](https://avatars.discourse-cdn.com/v4/letter/b/5daacb/32.png) [@b-omics](https://gromacs.bioexcel.eu/u/b-omics)\
**Post date:** [February 15, 2025, 2:53pm UTC](https://gromacs.bioexcel.eu/t/correct-setup-for-temperature-replica-exchange-t-remd-in-gromacs-without-plumed/11563/1 "2025-02-15T14:53:43Z")

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GROMACS version: 2024.4  
GROMACS modification: Yes/No  
Here post your question

I have a question regarding temperature replica exchange (T-REMD) in GROMACS ( **without** using PLUMED).

After completing energy minimization, NVT, and NPT equilibration using the same temperature, I plan to specify the desired temperatures and create multiple directories, each containing a `replex.mdp` file with the corresponding temperature.

I defined:

- `TEMP_DIR` = Variable name representing directories named according to their respective temperatures (e.g., `298.00/`, `300.60/`, etc.).

### **Is this the correct procedure to run T-REMD (without PLUMED)?**

1. **Generate TPR files for each temperature:**

for TEMP\_DIR in 298.00 300.60 303.23 305.8; do  
gmx grompp -f TEMP\_DIR/replex.mdp   
-c npt.gro   
-p topol.top   
-o TEMP\_DIR/tremd.tpr   
-r npt.gro   
-maxwarn 3  
done

1. 

```
mpirun -np 60 gmx_mpi mdrun -v -deffnm tremd -multidir 298.00 300.60 303.23 305.8 -replex 1000

```

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<div class="post-metadata">

**Author:** ![hess](https://dub1.discourse-cdn.com/flex017/user_avatar/gromacs.bioexcel.eu/hess/32/416_2.png) [@hess](https://gromacs.bioexcel.eu/u/hess)\
**Post date:** [February 19, 2025, 1:52pm UTC](https://gromacs.bioexcel.eu/t/correct-setup-for-temperature-replica-exchange-t-remd-in-gromacs-without-plumed/11563/2 "2025-02-19T13:52:17Z")

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Yes, apart from that you need to add the -replex option to mdrun.