Nonadiabatic Quantum Dynamics Predissociation of H2O+((B)over-tilde 2B2)

A quantum-mechanical study of the predissociation of H2O+ ((B) over tilde B-2(2)) is carried out by using wave packet propagations on ab initio potential energy surfaces connected by nonadiabatic couplings. The simulations show that within the first 30 fs 80% of the initial wave packet is transferred from the (B) over tilde B-2(2) to the (A) over tilde (2)A(1) electronic state through a conical intersection. A much slower transfer (in the ps time scale) from the (A) over tilde (2)A(1) to the (X) over tilde B-2(1), state due to a Renner-Teller coupling determines the fragmentation branching ratios, which are in accordance with the experimental measurements.