Dissociative ionization of CO2 in XUV pump and IR or visible probe pulses

Following the sudden single ionization of CO₂ in ultrashort extreme ultraviolet pump pulses, after exposure to delayed 780- or 400-nm probe-laser pulses, we propagate the coupled nuclear motion in {CO₂}^+ on the A{0. 16em{0ex}}^2ₔ, B0. 16em{0ex}{^2ₔ}^+, C0. 16em{0ex}{^2₆}^+, a0. 16em{0ex}{^4₆}^-, and b{0. 16em{0ex}}^4ₔ potential-energy surfaces of the excited molecular cation, including all vibronic degrees of freedom. We calculate potential-energy surfaces, diabatic couplings, and probe-laser-induced dipole couplings ab initio and heuristically model spin-orbit couplings. Based on our numerical results, we scrutinize the relative importance of diabatic, dipole, and spin-orbit couplings during the dissociation of {CO₂}^+ into O (^3P₆) +CO^+ (X{0. 16em{0ex}}^2^+) and O^+ (^4Sₔ) +CO (X{0. 16em{0ex}}^1^+), provide rovibrational-excitation distributions of the CO^+ fragments, and discuss pump-probe-delay-dependent kinetic-energy-release spectra. Addressing the nuclear dynamics near the conically intersecting A{0. 16em{0ex}}^2ₔ and B0. 16em{0ex}{^2ₔ}^+ states of {CO₂}^+, we reproduce the valence-hole oscillation period of 115 fs measured by Timmers et al. Phys. Rev. Lett. 113, 113003 (2014). In addition, we predict and characterize, in terms of quantum beats between specific stationary vibronic states, a 3. 1-ps fragment-yield oscillation.