anchor.diff:              cluster%excitation_level = 0
               cluster%amplitude = D0_normalisation
               cluster%cluster_to_det_sign = 1
  +            if (cluster%amplitude <= initiator_population) then
  +                ! Something has gone seriously wrong and the CC
  +                ! approximation is (most likely) not suitably for this system.
  +                ! Let the user be an idiot if they want to be...
  +                cdet%initiator_flag = 1
  +            end if
               ! Only one cluster of this size to choose => p_clust = 1
           case default
               ! Select cluster from the excitors on the current processor in
  
positive.code:         use qmc_common
          use fciqmc_restart, only: dump_restart
          use proc_pointers
          use spawning, only: create_spawned_particle_truncated
          use system, only: nel
  
          integer :: ireport, icycle
  
negative.code:             cdet%f = walker_dets(:,pos)
              cluster_population = walker_population(1,pos)
              cluster%excitors(1)%f => walker_dets(:,pos)
              if (walker_population(1,pos) <= initiator_population) then
                  cdet%initiator_flag = 1
              end if
              ! Now the rest...
              do i = 2, cluster%nexcitors
                  ! Select a position between in the excitors list.
  