Time-dependent excited-state molecular dynamics of photodissociation of lanthanide complexes for laser-assisted metal-organic chemical vapour deposition

Ab initio molecular dynamics (AIMD) algorithm was modified for treating time-dependent excited-state molecular dynamics (TDESMD). This algorithm addresses the situations when electron density and nuclear potential are being periodically driven by a strong laser field, which induces periodic population-depopulation Rabi cycles. The electron hopping between different potential energy surfaces, such as ground state and ligand-to-metal charge-transfer (LMCT) state, creates the nuclear trajectories. In the computed trajectories, the inter-atomic distances can demonstrate different regimes, from small oscillations to abrupt elongations, corresponding to fragmentation of the studied compound. This algorithm was used to explore photodissociation mechanisms for laser-assisted metal-organic chemical vapour deposition (LCVD or laser-assisted MOCVD) process using lanthanide cyclopentadienyl-type precursors. The computed fragments are compared with the ones elucidated experimentally using photoionisation time-of-flight mass spectrometry.