Driven by recent advances in ultrafast science, measuring electronic dynamics in molecular systems is becoming feasible on the attosecond time scale. Probing the motion of electrons at their natural time and length scales promises to shed light on the initial steps of photochemistry and light harvesting. Simulating attosecond dynamics from first principles is important for predicting and interpreting experiments, and for elucidating the role of electron correlation in these processes. This is challenging, however, as the intense fields require a non-perturbative treatment, and the large system sizes can make correlated techniques prohibitively expensive.<br/><br/>Here, time-dependent density functional theory (TDDFT) is a promising method with favorable scaling, although the strong fields and far-from-equilibrium dynamics can stress the validity of the exchange-correlation functional. I this talk I will present recent developments towards extending TDDFT for strong-field ionization using atom-centered basis sets and tuned range-separated hybrid functionals. Unlike traditional TDDFT, this approach has the correct long-range Coulomb potential and reduced self-interaction errors. The resulting laser intensity, angle, and molecular orbital-dependent ionization rates show good agreement with experimental values for a range of molecules. Additionally, simulations of the attosecond hole motion in OCS, iodoacetylene, and nitrosobenzene, will be presented, including both the case of tunnel ionization and X-ray triggers. These coherent hole dynamics have a relatively simple interpretation as a time evolving superposition of Lewis dot resonance structures.

Simulating ionization-triggered attosecond charge migration with TDDFT

255th National Meeting (2018)

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