State of native PLUMED interface in GROMACS

User discussions
1

I have some questions about the current state (and future development) of the native PLUMED interface that as been added in GROMACS 2025.

The GROMACS 2025 release notes state that:

A basic version of the PLUMED interface is now bundled by default in GROMACS.

and the PLUMED 2.10 documentation also simply says:

A basic PLUMED interface is already present in GROMACS.

However I didn’t find any list of features that are (or are not) supported by the GROMACS’ native PLUMED interface as opposed to applying the PLUMED patches.

My interest in this question is mainly as a software installer for Canada’s academic HPC infrastructure. In other words:

  1. Can I expect that with GROMACS 2025 (or 2026) most use-cases for GROMACS/PLUMED are already possible using the native interface and applying PLUMED patches to GROMACS is only needed for new features that have been added in the latest** PLUMED release.
  2. If the above is not is not yet the case, when do you expect that the native PLUMED integration will serve the needs for all (or most) use-cases (except for the most bleeding-edge features that surely will require the latest patches).
  3. Is there any documentation for what is not supported by the native PLUMED integration and therefore still requires applying the patches?

** i.e. The PLUMED release that was published after the latest major GROMACS transitioned into the stabilization phase of the development cycle.

Oliver

EDIT: Related links:

2

I’ve just added some related links to the top post.

And since the prior discussion was between @giovanni.bussi and @hess, I’m tagging them here because they are probably the best people to respond to my questions.

3

According to the reference manual and the PLUMED website, the current limitations of the interface are that it’s not able to use the ENERGY cv, incompatibility with thread-MPI, and some replica exchange methods are missing. I think that it should still cover most common use cases though.

4

Thanks.
The incompatibility with thread-MPI is also mentioned in PLUMED’s Code specific notes for various existing patch-sets, e.g. PLUMED v2.10’s patches for gromacs-2025-0.

In the Change Log for PLUMED 2.10 I also found the note:

  • New patches for MD codes:

    • A patch for GROMACS 2025 has been added, which is based on the native GROMACS interface to PLUMED and adds support for multiple walkers.

This suggests that all PLUMED patches for GROMACS 2025 and newer are based in the native GROMACS interface using GROMACS’ MDModule interface.

This thread on the PLUMED users list also suggests that certain methods are only available with older GROMACS releases.

So overall I get the impression that PLUMED patches for GROMACS 2025 and newer will be only marginally useful, since they would only include items that haven’t made it into the annual GROMACS release yet, but are likely to be included in next year’s release.

Oliver

5

I don’t know the exact policy, but the GROMACS releases only contain the interface. PLUMED can update and add any features that are compatible with the current interface in PLUMED packages.

6

Thanks.

It appears that MR 4622: Use multisim communicator in Plumed hadn’t been merged in time for GROMACS 2025 (and is still open even though 2026 is nearing its RC phase). I can’t say for sure whether PLUMED’s patch for gromacs-2025.0 (“A patch for GROMACS 2025 has been added, […] and adds support for multiple walkers.“) is identical to MR4622, but they seem to be somewhat related.

Also it appears that “H-REMD (REST2 method)” used to be available in combination with older GROMACS releases, but that the MDModule interface is still missing some parts to that they could work with more recent versions of GROMACS, since Issue #4940 is still open.