diff --git a/src/colvar/CoordinationBase.cpp b/src/colvar/CoordinationBase.cpp
index a96a6ffab8a7d42e848c0079a6ffde9a3717f04c..d6175db630953f65ecdfca915eb4e132f1f795d1 100644
--- a/src/colvar/CoordinationBase.cpp
+++ b/src/colvar/CoordinationBase.cpp
@@ -151,11 +151,8 @@ void CoordinationBase::calculate()
   }
 
   unsigned nt=OpenMP::getNumThreads();
-
   const unsigned nn=nl->size();
-
-  if(nt*stride*10>nn) nt=nn/stride/10;
-  if(nt==0)nt=1;
+  if(nt*stride*10>nn) nt=1;
 
   #pragma omp parallel num_threads(nt)
   {
diff --git a/src/colvar/EEFSolv.cpp b/src/colvar/EEFSolv.cpp
index 4dd204fe55a719c1f5006765cd300f2d4cfc9180..2a6ec617648a7e317cb07e62b45469f264a8d945 100644
--- a/src/colvar/EEFSolv.cpp
+++ b/src/colvar/EEFSolv.cpp
@@ -186,8 +186,7 @@ void EEFSolv::calculate() {
   Tensor deriv_box;
   unsigned nt=OpenMP::getNumThreads();
   const unsigned nn=nl.size();
-  if(nt*10>nn) nt=nn/10;
-  if(nt==0)nt=1;
+  if(nt*10>nn) nt=1;
   #pragma omp parallel num_threads(nt)
   {
     vector<Vector> deriv_omp(size);
diff --git a/src/vesselbase/ActionWithVessel.cpp b/src/vesselbase/ActionWithVessel.cpp
index 391b3b10a33a27372c88636d7679373c04ca6248..e3a1138654380dc156ed165bf22a4479405cdf02 100644
--- a/src/vesselbase/ActionWithVessel.cpp
+++ b/src/vesselbase/ActionWithVessel.cpp
@@ -273,8 +273,7 @@ void ActionWithVessel::runAllTasks() {
 
   // Get number of threads for OpenMP
   unsigned nt=OpenMP::getNumThreads();
-  if( nt*stride*10>nactive_tasks ) nt=nactive_tasks/stride/10;
-  if( nt==0 || !threadSafe() ) nt=1;
+  if( nt*stride*10>nactive_tasks || !threadSafe()) nt=1;
 
   // Get size for buffer
   unsigned bsize=0, bufsize=getSizeOfBuffer( bsize );
@@ -282,11 +281,6 @@ void ActionWithVessel::runAllTasks() {
   buffer.assign( buffer.size(), 0.0 );
   // Switch off calculation of derivatives in main loop
   if( dertime_can_be_off ) dertime=false;
-  // std::vector<unsigned> der_list;
-  // if( mydata ) der_list.resize( mydata->getSizeOfDerivativeList(), 0 );
-
-  // Build storage stuff for loop
-  // std::vector<double> buffer( bufsize, 0.0 );
 
   if(timers) stopwatch.start("2 Loop over tasks");
   #pragma omp parallel num_threads(nt)