Table 1.

Comparison of the energy barrier $\mathrm{\Delta }{G}^{‡}$ and Gibbs free energy change $\mathrm{\Delta }G$, measured in kcal/mol, for the C–C bond cleavage reaction using classical and quantum computational methods.

	HF	CASCI	VQE	DFT
$\mathrm{\Delta }{G}^{‡}$ with solvent	13.1	11.8	$7\pm 5$	8.3
$\mathrm{\Delta }G$ with solvent	$-41.1$	$-49.5$	$-51\pm 11$	$-10.8$
$\mathrm{\Delta }{G}^{‡}$ w/o solvent	2.6	1.4	$-4\pm 7$	–
$\mathrm{\Delta }G$ w/o solvent	$-59.3$	$-68.0$	$-65\pm 9$	–

HF and CASCI are calculated on classical computers, while VQE energies are obtained on a superconducting quantum computer. Both CASCI and VQE calculations are based on a (2e, 2o) active space. For the VQE energy, the mean and standard deviation from 4 independent experiments is reported. The DFT energies are obtained from previous work using M06-2X functional.