Figure 11.

Scheme of vibrational frequencies shifts within the initial 200 fs dynamics. Diabatic mixing between 1B_u⁺ and 1B_u^– leads to a frequency downshift during the evolution from the 1B_u⁺/1B_u^– mixed potential to the 2A_g^– potential. The red line in the 1B_u⁺/1B_u^– mixed potential depicts the shifted vibrational level due to the diabatic mixing. Frequency upshifts due to the 2A_g^– potential anharmonicity can be observed in the initial dynamics when diabatic mixing does not play a role. The intermediate states in the scheme for describing potential anharmonicity were omitted for clarity. (Reproduced with permission from [154].)