  Using quantum computers to simulate polyatomic reaction dynamics has an
exponential advantage in the amount of resources needed over classical
computers. Here we demonstrate an exact simulation of the dynamics of the
laser-driven isomerization reaction of asymmetric malondialdehydes. We
discretize space and time, decompose the Hamiltonian operator according to the
number of qubits and use Walsh-series approximation to implement the quantum
circuit for diagonal operators. We observe that the reaction evolves by means
of a tunneling mechanism through a potential barrier and the final state is in
close agreement with theoretical predictions. All quantum circuits are
implemented through IBM's QISKit platform in an ideal quantum simulator.
