anchor.diff:           end if
   
         else
  +         !---------------------------------------------------------------------------
  +         ! Compute the force knowing all particles. Compute all the accelerations with
  +         ! a local subset of all the particles, then reduce all accelerations
  +         !---------------------------------------------------------------------------
            allocate(a_reduced(3, npoints))
   
            !--------------------------------
  
positive.code: 
                 if (rank == i) a_comm_np_i = a
  
                 if (communicate_left) then
                    i_to_translate(1) = i
                    call mpi_group_translate_ranks(wgroup, 1, i_to_translate, mpi_group_to_left(i), i_translated, err)
  
negative.code:             allocate(m_np_i(N))
  
              !--------------------------------
              ! Loop over all processes
              !--------------------------------
  
              do i = 0, nprocs - 1
  