Prohibit SETTLE interactions on atoms with perturbed masses

[alexxy/gromacs.git] / docs / release-notes / 2021 / 2021.2.rst

diff --git a/docs/release-notes/2021/2021.2.rst b/docs/release-notes/2021/2021.2.rst
index 397ed3df3f41a6f7036c270851f1e532ca4a717f..fbcdafdde05b763343dca1842fc9d36ad10fdf3a 100644 (file)
--- a/docs/release-notes/2021/2021.2.rst
+++ b/docs/release-notes/2021/2021.2.rst
@@ -17,13 +17,22 @@ Fixes where mdrun could behave incorrectly
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 Removed a potential race condition with GPU update
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+"""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
 
 Fixed possible (but so far unobserved) race condition in coordinate copy when
 using GPU update with dipole moment calculation.
 
 :issue:`4024`
 
+Prohibited SETTLE interactions for atoms with perturbed masses
+""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""
+
+Older implementations produced varying degrees of wrong results because
+this has never been implemented. Now both ``mdrun`` and ``grompp``
+refuse to handle such a system, suggesting using normal constraints.
+
+:issue:`3959`
+
 Fixes for ``gmx`` tools
 ^^^^^^^^^^^^^^^^^^^^^^^