If you’re a molecular modeler using GROMACS for simulations, you probably know how important reproducibility and computational optimization can be. While SAMSON’s GROMACS Wizard comes bundled with a recent GROMACS version ready for cloud and local jobs, there are cases where switching to a custom version of GROMACS is not only desirable—it may be essential.
Why use a different GROMACS version?
There are a few common motivations:
- Reproducing published results: If a paper used a specific GROMACS version, matching that setup helps ensure consistency.
- System-specific optimization: Some institutional computing environments already have optimized GROMACS builds that make better use of available hardware.
- Consistency across projects or collaborators: Teams may standardize on a particular version.
How SAMSON makes it easy
The GROMACS Wizard in SAMSON offers a simple interface to switch to a different local version of GROMACS. Just follow these steps:
1. Click the Settings button in the GROMACS Wizard.

2. In the settings panel, check the option Use a different GROMACS version.

3. You’ll need to specify two paths:
- The GROMACS executable: Choose the path to
gmx(Linux/macOS) orgmx.exe(Windows). SAMSON will detect and display the version so you can verify it’s correct. - The force fields folder: This is typically where folders like
amber99sb.fforgromos54a7.ffare stored—e.g.,$HOME/gromacs/share/top/.
Things to watch for
- If the executable path is invalid or unrecognized, SAMSON will flag it as “invalid.” Double-check the location and version.
- Make sure your selected version is compatible with your input files and any topology or force field files you plan to use.
Whether you’re preparing a publication, working on a shared system, or just prefer to use a known environment, this little-known feature can save you time and ensure reproducibility across runs.
To dig deeper into how to configure this and explore other simulation settings, visit the full documentation page: GROMACS Wizard – Settings.
SAMSON and all SAMSON Extensions are free for non-commercial use. You can get SAMSON at https://www.samson-connect.net.
