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:     ! FCIQMC and CCMC.
      type(cluster_t), pointer :: cluster
  end type det_info_t
  
  contains
  
  
negative.code:             spe_sum = spe_sum + sys%basis%basis_fns(occ_list(iorb))%sp_eigv
          end do
  
      end function sum_sp_eigenvalues_occ_list
  
      pure function sum_sp_eigenvalues_bit_string(sys, f) result(spe_sum)
  
          ! In:
          !    sys: system being studied.
          !    f: bit-string representation of a determinant.
          ! Returns:
          !    Sum of the single particle energies.
  
          use system, only: sys_t
  
          real(p) :: spe_sum
          type(sys_t), intent(in) :: sys
          integer(i0), intent(in) :: f(:)
          integer :: occ(sys%nel)
  
          call decode_det(sys%basis, f, occ)
          spe_sum = sum_sp_eigenvalues_occ_list(sys, occ)
  
      end function sum_sp_eigenvalues_bit_string
  
  end module determinants
  