Recent advances in theoretical attosecond chemistry

In 2001, the first attosecond pulses were generated. Their application to molecules gave birth to the field of “attosecond chemistry” or in short “attochemistry”. The emergence of attosecond measurement tools has opened up the possibility to observe and control electrons in molecules, on their intrinsic timescale. Because of the time-energy uncertainty principle, attosecond or sub-femtosecond pulses have a large spectral bandwidth and can excite coherently several electronic states, i.e. electronic wavepackets. The latter are non-stationary and undergo pure electron dynamics called charge migration. Challenges faced in the application of theoretical methods to electron and coupled nuclear dynamics in molecules using attosecond technology has stimulated the development of novel computational approaches. In this Chapter, we report recent theoretical works investigating the application of attosecond science to polyatomic molecules. In particular, we discuss the photoionisation dynamics, the electron dynamics of electronic wavepackets notably the induced symmetry breaking, the electronic decoherence caused by nuclear motion but also the search for long-lived electronic coherence and electronic recoherence, the experimental observations of electron dynamics, and finally the charge-directed-reactivity, i.e. the nuclear dynamics induced by electronic wavepackets.