anchor.diff:      ! FCIQMC and CCMC.
       type(cluster_t), pointer :: cluster
   end type det_info_t
  +
  +interface sum_sp_eigenvalues
  +    module procedure :: sum_sp_eigenvalues_occ_list
  +    module procedure :: sum_sp_eigenvalues_bit_string
  +end interface sum_sp_eigenvalues
   
   contains
   
  
positive.code:             spe_sum = spe_sum + sys%basis%basis_fns(occ_list(iorb))%sp_eigv
          end do
  
      end function sum_sp_eigenvalues
  
  end module determinants
  
negative.code: 
      end subroutine update_sys_spin_info
  
      pure function sum_sp_eigenvalues_occ_list(sys, occ_list) result(spe_sum)
  
          ! In:
          !    sys: system being studied.
  