Change default MTS force group selection

Because of instabilities of aliphatic protons with the Amber
force fields, the default force group selection for multiple
time stepping has been changed to include longrange-nonbonded only.

Refs #3804

diff --git a/docs/user-guide/mdp-options.rst b/docs/user-guide/mdp-options.rst
index 6a6fd20750a62b2e24a85e3d5668369e9aa0ff5f..74f140063075e9c2fe814edd9750eeada5960c83 100644 (file)
--- a/docs/user-guide/mdp-options.rst
+++ b/docs/user-guide/mdp-options.rst
@@ -252,18 +252,15 @@ Run control
 
 .. mdp:: mts-level2-forces
 
-   (longrange-nonbonded nonbonded pair dihedral)
-   A list of force groups that will be evaluated only every
+   (longrange-nonbonded)
+   A list of one or more force groups that will be evaluated only every
    :mdp:`mts-level2-factor` steps. Supported entries are:
    ``longrange-nonbonded``, ``nonbonded``, ``pair``, ``dihedral``, ``angle``,
    ``pull`` and ``awh``. With ``pair`` the listed pair forces (such as 1-4)
    are selected. With ``dihedral`` all dihedrals are selected, including cmap.
    All other forces, including all restraints, are evaluated and
    integrated every step. When PME or Ewald is used for electrostatics
-   and/or LJ interactions, ``longrange-nonbonded`` has to be entered here.
-   The default value should work well for most standard atomistic simulations
-   and in particular for replacing virtual site treatment for increasing
-   the time step.
+   and/or LJ interactions, ``longrange-nonbonded`` can not be omitted here.
 
 .. mdp:: mts-level2-factor
 

diff --git a/src/gromacs/gmxpreprocess/readir.cpp b/src/gromacs/gmxpreprocess/readir.cpp
index ded12b74afe43836b64be410296aa1103856d289..f7cb14caecc42010d5d40e86f288caa5fbd33207 100644 (file)
--- a/src/gromacs/gmxpreprocess/readir.cpp
+++ b/src/gromacs/gmxpreprocess/readir.cpp
@@ -1996,8 +1996,7 @@ void get_ir(const char*     mdparin,
         opts->numMtsLevels = get_eint(&inp, "mts-levels", 2, wi);
         ir->mtsLevels.resize(2);
         gmx::MtsLevel& mtsLevel = ir->mtsLevels[1];
-        opts->mtsLevel2Forces   = setStringEntry(&inp, "mts-level2-forces",
-                                               "longrange-nonbonded nonbonded pair dihedral");
+        opts->mtsLevel2Forces   = setStringEntry(&inp, "mts-level2-forces", "longrange-nonbonded");
         mtsLevel.stepFactor     = get_eint(&inp, "mts-level2-factor", 2, wi);
 
         // We clear after reading without dynamics to not force the user to remove MTS mdp options