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arXiv · 2401.07491

Automatic Algorithm Switching for Accurate Quantum Chemical Calculations

Satoshi Imamura·Akihiko Kasagi·Eiji Yoshida
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Abstract

Quantum chemical calculations (QCC) are computational techniques to analyze the characteristics of molecules. The variational quantum eigensolver (VQE) designed for noisy intermediate-scale quantum (NISQ) computers can be used to calculate the ground-state energies of molecules, while coupled-cluster with singles, doubles, and perturbative triples [CCSD(T)] is regarded as a traditional gold standard algorithm in QCC. The advantage between CCSD(T) and VQE in terms of the accuracy of ground-state energy calculation differs depending on molecular structures. In this work, we propose an automatic algorithm switching (AAS) technique to accurately calculate the ground-state energies of a target molecule with different bond distances. It automatically switches CCSD(T) and VQE by identifying a bond distance where the accuracy of CCSD(T) begins to drop for a target molecule. Our evaluation using a noise-less quantum computer simulator demonstrates that AAS improves the accuracy to describe the bond breaking processes of molecules compared to CCSD(T) and VQE.

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Satoshi Imamura, Akihiko Kasagi, Eiji Yoshida. 2024-01-15. Automatic Algorithm Switching for Accurate Quantum Chemical Calculations. https://arxiv.org/abs/2401.07491

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