Fig. 2
From: Measuring correlation and entanglement between molecular orbitals on a trapped-ion quantum computer
One-orbital von Neumann entropies, two-orbital von Neumann entropies, and two-orbital mutual information, for 4 images of the NEB reaction path in which the CASSCF optimization is constrained to the \(\langle S^2 \rangle = 0\) singlet. Obtained using ideal noiseless simulations. For each row of panels, the corresponding molecular structure is displayed within the \(s1_i\) plot. When accounting for SSRs, the one-orbital entanglement \(E^{\text {SSR}}_i\) (not shown) is 0, and in this limit \(I^{\text {SSR}}_i = s1_i\)20. Orbital indexes correspond to orbitals labelled in Fig. 1b. When accounting for SSRs, two-orbital mutual information on vertical axis of rightmost panels corresponds to \(I^{\text {SSR}}_{i,j}\) (otherwise \(I_{i,j}\)).
