Fig. 3: Time-resolved dynamics for the average C=O bond potential energy per molecule.

Three conditions are compared: (a) \(\widetilde{\varepsilon }=2\times 1{0}^{-4}\) a.u. after exciting the LP at 2241 cm⁻¹ (the same as Fig. 2d); (b) \(\widetilde{\varepsilon }=4\times 1{0}^{-4}\) a.u. after exciting the LP at 2177 cm⁻¹ (the same as Fig. 2h); and (c) outside the cavity after exciting the ¹³C=O asymmetric stretch at 2262 cm⁻¹. In each subplot, the ¹²CO₂ solvent is drawn with a gray line and the 4.63% ¹³CO₂ solute is drawn with a red line. The y-axis is plotted in a logarithmic scale, and the yellow region denotes the time window (0.1 < t < 0.6 ps) during which the external pulse is applied. Note that although the nonequilibrium local IR spectrum in Fig. 2 was calculated using a single trajectory, 40 trajectories are averaged here to obtain an ensemble-averaged result; see Supplementary Methods for simulation details.