anchor.diff:  
       end subroutine update_sys_spin_info
   
  -    pure function sum_sp_eigenvalues(sys, occ_list) result(spe_sum)
  +    pure function sum_sp_eigenvalues_occ_list(sys, occ_list) result(spe_sum)
   
           ! In:
           !    sys: system being studied.
  
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:     ! 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
  
  