  We introduce a novel computational framework for excited-states molecular
quantum dynamics simulations driven by quantum computing-based
electronic-structure calculations. This framework leverages the fewest-switches
surface-hopping method for simulating the nuclear dynamics, and calculates the
required excited-state transition properties with different flavors of the
quantum subspace expansion and quantum equation-of-motion algorithms. We apply
our method to simulate the collision reaction between a hydrogen atom and a
hydrogen molecule. For this system, we critically compare the accuracy and
efficiency of different quantum subspace expansion and equation-of-motion
algorithms and show that only methods that can capture both weak and strong
electron correlation effects can properly describe the non-adiabatic effects
that tune the reactive event.
