Establish quantitative accuracy of Deep QSCI for the physical benzene dimer

Establish quantitative accuracy for the physical benzene-dimer interaction predicted by Deep QSCI, including through consistent orbital representations, selected-space convergence tests, and matched counterpoise-corrected comparisons.

Background

Deep QSCI produces an attractive interaction region for the benzene dimer with the 6-31G** basis, but the comparison with CCSD(T) uses different Hamiltonian constructions and different treatments of basis-set superposition error. The authors therefore do not regard the apparent numerical agreement as a quantitative validation.

The paper identifies quantitative accuracy, orbital consistency, convergence of the selected and reduced spaces, and matched counterpoise treatment as unresolved requirements for validating Deep QSCI as a method for physical benzene-dimer interaction energies.

References

Quantitative accuracy for the physical benzene-dimer interaction remains to be established. Further assessment of the monomer QSCI states, orbital consistency, and reduced-space convergence is needed to clarify the basis-set dependence while preserving the computational benefit of monomer reuse.

— A Divide-and-Conquer Quantum-Selected Configuration Interaction for Evaluating $π$-$π$ Stacking Interaction Energies in the Benzene Dimer  (2609.36708 - Tajima et al., 29 Sep 2026) in Section 5, Results; Section 7, Conclusion

This behavior may involve limitations of the monomer QSCI state, the orbital-index mapping, or the reduced-space construction. The present results do not distinguish these possibilities.

— A Divide-and-Conquer Quantum-Selected Configuration Interaction for Evaluating $π$-$π$ Stacking Interaction Energies in the Benzene Dimer  (2609.36708 - Tajima et al., 29 Sep 2026) in Section 5, Results; Section 6, Discussion

Developing this extension while maintaining orbital consistency and a fixed total electron number remains a direction for future work.

— A Divide-and-Conquer Quantum-Selected Configuration Interaction for Evaluating $π$-$π$ Stacking Interaction Energies in the Benzene Dimer  (2609.36708 - Tajima et al., 29 Sep 2026) in Section 6, Discussion; Section 7, Conclusion