Stark mixing by ion-Rydberg atom (molecule) collisions

Classical molecular dynamics simulations are performed to cover Stark mixing transitions (nℓ→nℓ′nℓ→nℓ′) in Rydberg atoms by collision with slow ions. Accuracy is tested by comparison with the exact analytical classical probabilities Pℓ′ℓ(n) previously obtained when the ion–atom potential is taken as the long-range ion–dipole interaction. The results are provided not only for the ion–dipole interaction but also for the full electrostatic interaction. It is shown, by comparison, that the ion–dipole potential alone provides reliable probabilities. The method is highly accurate and is very amenable to ready inclusion of other processes competing with Stark mixing.