diff --git a/src/surface/surface_generator.cpp b/src/surface/surface_generator.cpp
index 0fa0fc9..d33ad8a 100644
--- a/src/surface/surface_generator.cpp
+++ b/src/surface/surface_generator.cpp
@@ -1,68 +1,73 @@
 /*
  *  SPDX-License-Indentifier: AGPL-3.0-or-later
  *
  *  Copyright (©) 2016-2022 EPFL (École Polytechnique Fédérale de Lausanne),
  *  Laboratory (LSMS - Laboratoire de Simulation en Mécanique des Solides)
  *  Copyright (©) 2020-2022 Lucas Frérot
  *
  *  This program is free software: you can redistribute it and/or modify
  *  it under the terms of the GNU Affero General Public License as published
  *  by the Free Software Foundation, either version 3 of the License, or
  *  (at your option) any later version.
  *
  *  This program is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  *  GNU Affero General Public License for more details.
  *
  *  You should have received a copy of the GNU Affero General Public License
  *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
  *
  */
 /* -------------------------------------------------------------------------- */
 #include "surface_generator.hh"
 #include "partitioner.hh"
 #include <algorithm>
 /* -------------------------------------------------------------------------- */
 
 namespace tamaas {
 
 /* -------------------------------------------------------------------------- */
 
 template <UInt dim>
 void SurfaceGenerator<dim>::setSizes(std::array<UInt, dim> n) {
   global_size = n;
   auto local_size = Partitioner<dim>::local_size(std::move(n));
   grid.resize(local_size);
 
-  Logger().get(LogLevel::debug)
-      << TAMAAS_DEBUG_MSG("Local N0 " << local_size[0]);
+  Logger().get(LogLevel::debug) << TAMAAS_DEBUG_MSG(
+      "Local N0 " << local_size[0] << ", Global N0 " << global_size[0]);
+
+  // TODO exclude invalid ranks from the main communicator
+  if (global_size[0] != 0 and local_size[0] == 0)
+    TAMAAS_EXCEPTION("FFT data partition gave no data on ["
+                     << mpi::rank() << "|" << mpi::size() << "]");
 }
 
 /* -------------------------------------------------------------------------- */
 
 template <UInt dim>
 void SurfaceGenerator<dim>::setSizes(const UInt n[dim]) {
   std::array<UInt, dim> size;
   std::copy_n(n, dim, size.begin());
   setSizes(std::move(size));
 }
 
 /* -------------------------------------------------------------------------- */
 
 template <UInt dim>
 void SurfaceGenerator<dim>::setRandomSeed(long seed) {
   mpi::bcast(&seed, 1);
   random_seed = seed;
 
   if (seed < 1)
     Logger().get(LogLevel::warning)
         << "Setting a seed < 1 is the same as seed = 1\n";
 }
 
 /* -------------------------------------------------------------------------- */
 
 template class SurfaceGenerator<1>;
 template class SurfaceGenerator<2>;
 
 }  // namespace tamaas