anchor.diff:                      ! probability by nprocs.  See comments in select_cluster
                       ! for more details.
                       if (.not. seen_D0) then
  -                        ! This is the first time this thread is spawning from D0 in this block of iterations (*)
  +                        ! This is the first time this thread is spawning from D0 in this block of iterations
                           ! so it needs to be converted into a det_info_t object for the excitation
                           ! generators. On subsequent calls, cdet does not need to change.
                           
  
positive.code: 
                  it = get_thread_id()
                  iexcip_pos = 0
                  
                  !$omp do schedule(dynamic,200) 
                  do iattempt = 1, selection_data%nclusters
                      if (iattempt <= selection_data%nsingle_excitors) then
                          ! As noncomposite clusters can't be above truncation level or linked-only all can accumulate +
                          ! propagate. Only need to check not selecting the reference as we treat it separately.
  
negative.code:                         end if
  
                      ! For OpenMP scalability, have this test inside a single loop rather
                      ! than attempt to parallelise over two separate loops.
                      else
                          if (ccmc_in%even_selection) then
                              call select_cluster_truncated(rng(it), sys, qs%psip_list, qs%ref%f0, &
                                                          ccmc_in%linked, selection_data%nstochastic_clusters, D0_normalisation, &
  