Quantum trajectory approach to chemical reaction dynamics: Application to the capture process

National audience; In this contribution, we expose a new mixed quantum-classical reaction dynamics method whosenovelty is that it is entirely based on trajectories. Our approach rests on the concept of quantumtrajectory, which has been long been considered a philosophical and interpretative tool for quantummechanics [1]. Recently, quantum trajectories have been “rediscovered” with the goal of developinga totally new and unconventional computational method for doing quantum reaction dynamics [2,3].The most recent formulation, due to Bill Poirier and coworkers [4-6], sums up as a system ofcoupled ordinary differential equations (ODEs), that can be propagated in an extremely stable andaccurate manner. Potential advantages of this method are easily seen: (i) accurate propagation canbe extended to very large internuclear distances at low temperature; (ii) the propagation of onequantum degree of freedom together with several—possibly many—classical degrees of freedomsimply amounts to solving a “cheap” classical-like ODE system.Here we elaborate on our companion communication “Quantum trajectory capture at low and ultralowtemperature”. The above quantum trajectory approach is introduced and its physical as well ascomputational advantages are detailed, with special emphasis on the capture process.