Disable MTS with SD integrator

The SD integrator requires different damping coefficients for
the different MTS forces and we currently don't have the different
MTS forces available separately in the integrator.

Fixes #3775

diff --git a/docs/user-guide/mdp-options.rst b/docs/user-guide/mdp-options.rst
index 251172ae96120975235720a2b3c4af5c990f71bc..e547ec841812bea5bfaae306c5df118672ca36cf 100644 (file)
--- a/docs/user-guide/mdp-options.rst
+++ b/docs/user-guide/mdp-options.rst
@@ -241,7 +241,8 @@ Run control
 
       Use a multiple timing-stepping integrator to evaluate some forces, as specified
       by :mdp:`mts-level2-forces` every :mdp:`mts-level2-factor` integration
-      steps. All other forces are evaluated at every step.
+      steps. All other forces are evaluated at every step. MTS is currently
+      only supported with :mdp-value:`integrator=md`.
 
 .. mdp:: mts-levels
 

diff --git a/src/gromacs/gmxpreprocess/readir.cpp b/src/gromacs/gmxpreprocess/readir.cpp
index 2edc32384d8d18298892a67c7b8fd88b918b74aa..1a3df9b8e55b0252a37bf9e7405b8a06ad22b384 100644 (file)
--- a/src/gromacs/gmxpreprocess/readir.cpp
+++ b/src/gromacs/gmxpreprocess/readir.cpp
@@ -249,11 +249,14 @@ static void setupMtsLevels(gmx::ArrayRef<gmx::MtsLevel> mtsLevels,
                            const t_gromppopts&          opts,
                            warninp_t                    wi)
 {
-    if (!(ir.eI == eiMD || ir.eI == eiSD1))
+    /* MD-VV has no MTS support yet.
+     * SD1 needs different scaling coefficients for the different MTS forces
+     * and the different forces are currently not available in ForceBuffers.
+     */
+    if (ir.eI != eiMD)
     {
         auto message = gmx::formatString(
-                "Multiple time stepping is only supported with integrators %s and %s",
-                ei_names[eiMD], ei_names[eiSD1]);
+                "Multiple time stepping is only supported with integrator %s", ei_names[eiMD]);
         warning_error(wi, message.c_str());
     }
     if (opts.numMtsLevels != 2)