diff --git a/src/ML-PACE/compute_pace.cpp b/src/ML-PACE/compute_pace.cpp
index d99676491d..d66952d1f9 100644
--- a/src/ML-PACE/compute_pace.cpp
+++ b/src/ML-PACE/compute_pace.cpp
@@ -62,6 +62,7 @@ double ComputePaceAtom::compute_scalar() {
     auto pair = (PairPACEActiveLearning *) pair_pace_al;
 
     if (invoked_scalar != pair->bevaluator_timestep) {
+        //TODO: somehow control the frequency of extra computation and warn user about adjusting gamma_freq?
 //        utils::logmesg(lmp,"[ComputePaceAtom::compute_scalar] Reseting timestep shift to {} (pace timestep={}) and recomputing\n",invoked_scalar,pair->bevaluator_timestep);
         pair->bevaluator_timestep_shift = invoked_scalar;
         //TODO: is that right calling of pair pace compute?
@@ -76,6 +77,7 @@ void ComputePaceAtom::compute_peratom() {
     invoked_peratom = update->ntimestep;
     auto pair = (PairPACEActiveLearning *) pair_pace_al;
     if (invoked_peratom != pair->bevaluator_timestep) {
+        //TODO: somehow control the frequency of extra computation and warn user about adjusting gamma_freq?
 //        utils::logmesg(lmp,"[ComputePaceAtom::compute_peratom] Reseting timestep shift to {} (pace timestep={}) and recomputing\n",invoked_peratom,pair->bevaluator_timestep);
         pair->bevaluator_timestep_shift = invoked_peratom;
         //TODO: is that right calling of pair pace compute?
diff --git a/src/ML-PACE/pair_pace_al.cpp b/src/ML-PACE/pair_pace_al.cpp
index ce8a75a6e5..b20798f3a7 100644
--- a/src/ML-PACE/pair_pace_al.cpp
+++ b/src/ML-PACE/pair_pace_al.cpp
@@ -313,27 +313,27 @@ void PairPACEActiveLearning::compute(int eflag, int vflag) {
 
     if (vflag_fdotr) virial_fdotr_compute();
 
-    //TODO: check correctness of MPI usage, maybe use comm->me==0 instead ?
+    //TODO: check correctness of MPI usage
     if (is_bevaluator) {
         //gather together max_gamma_grade_per_structure
         MPI_Allreduce(&max_gamma_grade, &max_gamma_grade_per_structure, 1, MPI_DOUBLE, MPI_MAX, world);
-        int mpi_rank;
-        MPI_Comm_rank(world, &mpi_rank);
 
         if (max_gamma_grade_per_structure > gamma_upper_bound) {
-            if (mpi_rank == 0)
+            if (comm->me == 0)
                 dump_extrapolation_grade(update->ntimestep, max_gamma_grade_per_structure);
             if (is_dump_extrapolative_structures) dump->write();
             MPI_Barrier(world);
 
-            if (mpi_rank == 0) {
-                error->all(FLERR, "Extrapolation grade is too large, stopping...\n");
-            }
+            if (comm->me == 0)
+                error->all(FLERR,
+                           "Extrapolation grade is too large (gamma={:.3f} > gamma_upper_bound={:.3f}, timestep={}), stopping...\n",
+                           max_gamma_grade_per_structure, gamma_upper_bound, current_timestep);
 
-            MPI_Abort(world, 1); //abort properly with error code '1' if not using 4 processes
+            MPI_Barrier(world);
+            MPI_Abort(world, 1); //abort properly with error code '1' if not using many processes
             exit(EXIT_FAILURE);
         } else if (max_gamma_grade_per_structure > gamma_lower_bound) {
-            if (mpi_rank == 0)
+            if (comm->me == 0)
                 dump_extrapolation_grade(update->ntimestep, max_gamma_grade_per_structure);
             if (is_dump_extrapolative_structures)
                 dump->write();