GROMACS 2022.3 release notes

This version was released on September 2nd, 2022. These release notes document the changes that have taken place in GROMACS since the previous 2022.2 version, to fix known issues. It also incorporates all fixes made in version 2021.6 and earlier, which you can find described in the Release notes.

Fixes where mdrun could behave incorrectly

Energy minimization would not converge with GPU and without DD

The steepest descent and conjugate gradient minimizers would not converge when using a GPU for the nonbonded interactions and not using domain decomposition.

Issue 4533

Settings of lambda-only replica exchange is mistakenly routed to temperature+lambda branch

When replica exchange of lambda-only mode is enabled, all reference temperatures ref-t are the same among replicas. However, another branch temperature+lambda is used according to log messages.

Issue 4580

Fixes for gmx tools

Fix pdb2gmx vsite assignment for tetrahedral secondary amines

The pdb2gmx vsite assignment code would always select a planar vsite for structures like secondary amines based solely on the number of atoms, without taking geometry into account. Changed to take geometry into account.

Issue 4573

Disallow C-rescale barostat without temperature coupling

The C-rescale barostat needs a reference temperature which is currently taken from the thermostat. A check is added to grompp for temperature coupling or BD/SD being present. Also a warning is generated when the reference temperature are not all equal.

Issue 4495

Prevent hbond merging in gmx hbond for non-compatible options

The option to merge multiple hbonds from one donor-acceptor pair does not work with other options that rely on analysing all hydrogen bonds, or changing the search for donor-acceptor pairs. Due to this, the tool will stop if known incompatible combinations are used.

When using -hbn to export the hydrogen bonding information with merging enabled, previously indices of arbitrary hydrogens were printed. Now, to avoid confusion, the index file contains -1 instead. Use -nomerge option if full hydrogen bond information is needed.

Issue 3837

Fix generation of duplicate groups in index generation

Both gmx make_ndx and gmx select would duplicate index groups for molecules not defined as Protein or Nucleotides due to a logic error in the code, where any extra group defined in the system would cause the detection to be run again and generate the duplicate groups.

Issue 4524

Fixes that affect portability

Further fix to nvcc flag detection

Version 2022.1 fixed a nvcc flag detection issue for gcc version 11, but this fix resulted in issues for older gcc versions. Version 2022.2 resolved this for gcc version 7, but issues remained for other gcc versions. This release provides a fix that should prevent this issue for all gcc versions.

Issue 4539

Document incompatibility of gcc-11 and nvcc 11.6.1

A known incompatibility between the default gcc and nvcc compiler on Ubuntu 22.04 has been documented, with a guide how to circumvent the issue.

Issue 4574


Improve mdrun log file energy output formatting

The mdrun log file now prints more energy-field names in abbreviated forms so as to avoid exceeding the maximum column lengths available.

Improve warning message about AVX_128_FMA SIMD

This instruction set only works on early AMD CPUs that support their FMA4 extensions. Since Zen1, AMD has instead moved to support FMA3 (similar to Intel hardware), which unfortunately means SIMD instruction sets are NOT incremental. We now detect this for parallel runs and stick to vanilla 256-bit AVX, and properly detect when the FMA4 instruction set is used on non-compatible hardware and warn why the run is likely to crash.

Issue 4526

Remove unnecessary memory re-allocations for GPU update runs

An issue has been fixed where GPU memory allocations were repeatedly being performed unecessarily for runs with GPU update enabled, significantly impacting performance in some cases. The memory allocations are now only performed when necessary.