Soongsil University Team Estimates Ground-State Energy with 0.00 mHa Deviation

Researchers at Soongsil University and collaborating institutions have demonstrated a hybrid quantum-classical approach for calculating molecular ground-state energies using Sample-Based Quantum Diagonalization (SQD). The study evaluates the molecular systems HeH⁺, ArH⁺, and H₂O, showing that the technique can accurately reproduce potential-energy curves while operating within the capabilities of today’s quantum hardware. The results demonstrate that SQD can achieve accuracy comparable to established quantum chemistry methods, highlighting its potential as a practical tool for studying increasingly complex molecular systems on near-term quantum computers. Until now, accurate ground-state energy calculations for molecules required computationally demanding methods like coupled-cluster singles and doubles (CCSD). The deviations from complete active…