anchor.diff:  
           do idet = 1, spawn%head(0,0) ! loop over walkers/dets
   
  -            pop = int(spawn%sdata(spawn%bit_str_len+1:spawn%bit_str_len+spawn%ntypes, idet), int_p)
  +            int_pop = int(spawn%sdata(spawn%bit_str_len+1:spawn%bit_str_len+spawn%ntypes, idet), int_p)
  +            real_pop = real(int_pop(1),p) / real_factor
               ftmp = int(spawn%sdata(:sys%basis%tensor_label_len,idet),i0)
               ! Need to generate spawned walker data to perform evolution.
               tmp_data(1) = sc0_ptr(sys, cdet%f) - H00
  
positive.code:         use dSFMT_interface, only: dSFMT_t
          use excitations, only: excit_t
          use system, only: sys_t
  
          type(sys_t), intent(in) :: sys
          type(spawn_t), intent(inout) :: spawn
  
negative.code:         real(p), target :: tmp_data(sampling_size)
          type(excit_t) :: connection
          real(p) :: hmatel
          integer :: idet, iparticle, nattempts_current_det
          integer(int_p) :: nspawned
          integer(int_p) :: int_pop(spawn%ntypes)
          real(p) :: real_pop
          real(p) :: list_pop
          integer(i0), target :: ftmp(sys%basis%tensor_label_len)
  
  