anchor.diff:          integer(int_p), intent(inout) :: ndeath
           integer, intent(in) :: nload_slots
   
  -        real(p), target :: tmp_data(1)
           type(excit_t) :: connection
           real(p) :: hmatel
           integer :: idet, iparticle, nattempts_current_det
  
positive.code: 
              ! Clone or die.
              ! list_pop is meaningless as particle_t%nparticles is updated upon annihilation.
              call stochastic_death(rng, qs, tmp_data(1), qs%shift(1), int_pop(1), list_pop, ndeath)
              ! Update population of walkers on current determinant.
              spawn_recv%sdata(spawn_recv%bit_str_len+1:spawn_recv%bit_str_len+spawn_recv%ntypes, idet) = int_pop
  
          end do
  
      end subroutine evolve_spawned_walkers
  
  end module fciqmc
  
negative.code:         integer(int_p) :: int_pop(spawn_recv%ntypes)
          real(p) :: real_pop
          real(p) :: list_pop
  
          allocate(cdet%f(sys%basis%tensor_label_len))
          allocate(cdet%data(1))
  
          do idet = 1, spawn_recv%head(0,0) ! loop over walkers/dets
  
              int_pop = int(spawn_recv%sdata(spawn_recv%bit_str_len+1:spawn_recv%bit_str_len+spawn_recv%ntypes, idet), int_p)
              real_pop = real(int_pop(1),p) / qs%psip_list%pop_real_factor
              cdet%f = int(spawn_recv%sdata(:sys%basis%tensor_label_len,idet),i0)
              ! Need to generate spawned walker data to perform evolution.
              cdet%data(1) = sc0_ptr(sys, cdet%f) - qs%ref%H00
  
              call decoder_ptr(sys, cdet%f, cdet)
  
  