GROMACS 2023.5 release notes
----------------------------

This version was released on TODO, 2024. These release notes
document the changes that have taken place in |Gromacs| since the
previous 2023.4 version, to fix known issues. It also incorporates all
fixes made in version 2022.6 and earlier, which you can find described
in the :ref:`release-notes`.

.. Note to developers!
   Please use """"""" to underline the individual entries for fixed issues in the subfolders,
   otherwise the formatting on the webpage is messed up.
   Also, please use the syntax :issue:`number` to reference issues on GitLab, without
   a space between the colon and number!

Fixes where mdrun could behave incorrectly
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Correct forces with virtual_sites1
""""""""""""""""""""""""""""""""""

Virtual sites with a single constructing atom did not have their
force distributed to the constructing atom. This likely did not cause
silent errors, as this completely defeats the purpose of such virtual
sites.

:issue:`4978`

Avoid rounding errors with Parrinello-Rahman coupling of triclinic boxes
""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""

With triclinic boxes and isotropic or diagonal Parrinello-Rahman pressure
coupling, the off-diagonal scaling matrix arguments could be non-zero.
This was harmless, apart from causing an assertion failure when update
was executed on a GPU.

:issue:`4974`

Fixes for ``gmx`` tools
^^^^^^^^^^^^^^^^^^^^^^^

Fix LJ combination rules mixup in nonbonded-benchmark tool
""""""""""""""""""""""""""""""""""""""""""""""""""""""""""

The gmx nonbonded-benchmark tool would use geometric LH combination rules instead
of Lortenz-Berthelot and Lortenz-Berthelot instead of no combination rules.

:issue:`4963`

Fixes that affect portability
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Use RDTIME instead of RDCYCLE on RISC-V
"""""""""""""""""""""""""""""""""""""""

Starting with Linux 6.6, the ``rdcycle`` instruction cannot be called from
userland for security reasons, making |Gromacs| fail with ``SIGILL``.
Now it is replaced with ``rdtime``.


:issue:`4967`

Miscellaneous
^^^^^^^^^^^^^

