Deprecated functionality

Changes anticipated to GROMACS 2022 functionality

Functionality deprecated in GROMACS 2022

GMX_OPENCL_NB_CLUSTER_SIZE CMake variable deprecated in favor of GMX_GPU_NB_CLUSTER_SIZE

Both OpenCL and SYCL support different cluster sizes, so GMX_GPU_NB_CLUSTER_SIZE should be used going forward.

The built-in viewer gmx view will be removed

There is little use and no tests of this functionality, so it is not worth attempting to maintain moving forward.

Issue 4296

The analysis tool gmx chi will be removed

This tool has not been functional for a few years. Please comment at the linked issue if you have any interest in it.

Issue 4108

Guessing masses and atomic radii from atom names is deprecated

When atom masses or van-der-Waals radii are needed, we suggest building a proper GROMACS topology instead of using PDB files directly, even if the tool supports it.

Issue 3368 Issue 4288

Functionality deprecated in GROMACS 2021

mdrun -deffnm to be removed

This functionality is convenient when running very simple simulations, because it permits grouping of a set of files that then differ only their suffix. However, it does not work in the wider case of an mdrun module (or modules) writing multiple .xvg output files. The resulting filenames collide. That, and its interaction with checkpointing and appending, have led to quite a few bug reports.

Because users can use a folder to group files (a standard mechanism that they understand from experience outside of GROMACS), we can build and test better software for them if we remove the erstwhile convenience of mdrun -deffnm. Please update your workflows accordingly.

Issue 3818

OpenCL to be removed as a GPU framework

Issue 3818 Work is underway for ports to AMD and Intel GPUs, and it is likely that those ports will not be based on the current GROMACS OpenCL port. Nvidia GPUs are targeted by the CUDA port, and no changes are expectd there. The core team can’t maintain, test, and extend up to 4 ports with current resource levels. Since there are no prospects of an emerging GPU vendor in HPC needing OpenCL support, we will remove the OpenCL port once AMD and Intel support is established in other ways.

Support for version 1 of the hardware locality library hwloc

Issue 3818 Version 2 has been supported in GROMACS for several years. The capabilities of newer hardware and hardware-support APIs are of most interest for GROMACS moving forward, so we should minimize our testing work and encourage clusters to upgrade older hwloc installations.

Legacy API

Issue 3818 The legacy installed headers have been deprecated for a while, however we wish to state more broadly that all headers found within the src directory tree of GROMACS are intended for internal consumption only, and are thus subject to change without notice. Further, the form and contents of the libgromacs library and related CMake targets may change as we move towards building APIs and supporting machinery that can be stable and supported in the long term.

Functionality deprecated in GROMACS 2019

Generation of virtual sites to replace aromatic rings in standard residues

Issue 3254 These are thought to produce artefacts under some circumstances (unpublished results), were never well tested, are not widely used, and we need to simplify pdb2gmx.

Benchmarking options only available with gmx benchmark

Issue 3255 Options such as -confout, -resethway, -resetstep are not intended for use by regular mdrun users, so making them only available with a dedicated tool is more clear. Also, this permits us to customize defaults for e.g. writing files at the end of a simulation part in ways that suit the respective mdrun and benchmark use cases, so -confout will no longer be required.

gmx mdrun -nsteps

Issue 3256 The number of simulation steps described by the .tpr file can be changed with gmx convert-tpr, or altered in .mdp file before the call to gmx grompp. The convenience of this mdrun option was outweighted by the doubtful quality of its implementation, no clear record in the log file, and lack of maintenance.