Photodissociation dynamics of the LiF molecule: Two- and three-state descriptions

Abstract

The photodissociation of the lithium fluoride molecule gathered much attention lately. Theoretical works treating this subject usually consider the 1 1 + and 2 1 + electronic states, which are coupled nonadiabatically. As a continuation of a previous work, we intend to highlight the importance of the 1 1 state by investigating the kinetic energy and angular distribution of the photofragments. Besides, our results pointed out the importance of the molecular rotation.

Control of photodissociation with the dynamic Stark effect induced by THz pulses

“…Moreover, as the field changes sign, the excited states develop potential wells in the direction where previously Σ 1 had (up/down), which results in the rotation of the Π 1 wavepacket toward the pump-forbidden θ = {0, π} direction. This in turn leads to the development of the interference structures observable in the angular distribution [43]. If the control pulse is applied after the system is pumped but before the excited wavepackets reach the AC region the angular distributions are more structured owing to the previously mentioned population transfer between the various states.…”

“…Lithim fluoride along the other alkali-halides have been a popular testing ground for nonadiabatic dynamics during the photodissociation of these molecules due to the avoided crossing (AC) between their lowest lying 1 Σ + electronic states. In our previous works on this system we showed that a realistic theoretical description must also include the first 1 Π state [42,43]. Accordingly, in the present investigation we model the LiF molecule as a three-level system considering the 1 1 Σ + , 2 1 Σ + and 1 1 Π electronic states, labeled throughout the paper as Σ 1 , Σ 2 and Π 1 .…”

“…In the present work our showcase example is the lithium fluoride molecule, therefore the control procedure relies on the dipole limit. The LiF molecule has already been studied in our former works [42,43] where we discussed the role played by the lowest-lying Π electronic state in the photodissociation of the molecule through the population dynamics, the angular distribution and the kinetic energy release (KER) spectra of the photofragments. Describing appropriately the light-induced nonadiabatic phenomena the rotational degree of freedom has already been taken into account as dynamical variable in those works.…”

Fotodisszociáció szabályozása THz pulzussal indukált Stark effektussal

“…Előző munkáinkban [9] azt is megmutattuk, hogy a molekuladinamika valósághű leírásához a szimulációkban figyelembe kell vennünk a forgási szabadsági fokot. A terahertzes sugárzás köztudottan erős forgató hatását figyelembe véve, a jelen esetben ez hatványozottan érvényes.…”

Polariton Induced Conical Intersection and Berry Phase

“…Thus, it is vital to reveal the characteristic features of these LI-CIs. Previous theoretical studies, employing the classical description of light, investigated the nature of the LICI in diatomic molecules 32,33,[35][36][37][38][39][40] and to what extent the geometric phase of the LICI is similar to the natural CIs for polyatomic molecule in a field free space. 31,[41][42][43] It has been demonstrated that LICI strongly impact the spectroscopic and dynamical properties of molecules, such as the molecular alignment, the photodissociation probability, molecular spectra, and the angular distribution of the dissociation photofragment.…”