     // prepare CUDA environment
     int n_gpus = get_num_gpus();
     std::vector<float*> d_coords_sorted(n_gpus);
-    std::vector<int*> d_local_nh(n_gpus);
+    std::vector<unsigned int*> d_clustering(n_gpus);
     {
       // sort coords according to free energies
       std::vector<float> tmp_coords_sorted(n_rows * n_cols);

    }
    local_nh.insert(i_ref);
    return local_nh;
  }

  std::vector<std::size_t>

  }


/*
  __global__ void
  high_density_neighborhood_krnl(std::size_t offset
                               , float* d_coords_sorted
