GROMACS 2026.4 release notes¶
This version was released on TODO, 2026. These release notes document the changes that have taken place in GROMACS since the previous 2026.3 version, to fix known issues. It also incorporates all fixes made in version 2025.4 and earlier, which you can find described in the Release notes.
Fixes where mdrun could behave incorrectly¶
Fix PME heap buffer overflow with multiple PME ranks¶
When the local PME grid required SIMD padding in the z dimension,
major-dimension overlap communication could write beyond its communication
buffer. This could corrupt memory or crash mdrun when PME used multiple
PME ranks, most readily with pme-order = 5.
Fixed MPI-parallel mdrun -plumed aborting at startup¶
Any MPI-parallel run using PLUMED aborted at startup with MPI_ERR_COMM:
PLUMED reads the setMPIComm argument as a pointer, but the communicator
was passed by value. Only 2026 was affected.
Worked around SYCL miscompilation in PME by oneAPI 2026.x¶
With all oneAPI versions 2026.x (and until a fix arrives), the SYCL PME GPU gather kernel on sufficiently large systems is affected by a miscompilation that causes a crash. Earlier oneAPI versions are not affected. Results are correct if mdrun does not crash.
The issue is now worked around by always allocating some per-workgroup shared local memory, which can be more than is strictly required, but which is unlikely to affect performance noticeably.
Fixes for gmx tools¶
Fix stack overflow in grompp with large ifdef blocks¶
A recursion was replaced with a plain loop to avoid gmx grompp
crashing with large ifdef blocks.
Increased precision of time processing in gmx eneconv¶
All internal time processing in gmx eneconv now preserves the full double
precision of the time stamps. This avoids picking of incorrect frames when
times are large and intervals are small.
Fixes that affect portability¶
Fixed SYCL build with HeFFTe¶
Miscellaneous¶
Updated DOI to the preprint describing AMBER14SB and AMBER19SB conversion and validation¶
AMBER14SB and AMBER19SB force field itp files contained a placeholder link the preprint describing the conversion and validation steps. Now that the preprint is uploaded on ChemRxiv, the placeholder was replaced with the DOI of the preprint, doi:10.26434/chemrxiv.15006112/v1.