Angle-dependent strong-field molecular ionization rates with tuned range-separated time-dependent density functional...

Area of Science:

• Quantum Chemistry
• Computational Physics
• Theoretical Chemistry

Background:

• Strong-field ionization is crucial for processes like high harmonic generation and photodamage.
• Modeling molecular ionization dynamics is challenging due to large wavefunctions and intense fields.
• Accurate simulation requires non-perturbative time-dependent electronic structure methods.

Purpose of the Study:

• To develop a time-dependent density functional theory (TD-DFT) approach for strong-field ionization.
• To utilize Gaussian-type orbitals (GTOs) for accurate wavefunction representation.
• To capture ionization rates and dynamics in atoms and small molecules.

Main Methods:

• Propagating the electronic density matrix in time with a time-dependent laser potential.
• Employing a spatial non-Hermitian complex absorbing potential (CAP) to remove ionized charge.
• Using a tuned range-separated functional (LC-PBE*) with correct asymptotic potential and reduced delocalization error.

Main Results:

• Calculated ionization rates for H, N2, and iodoacetylene under varied field conditions.
• Demonstrated quantitative agreement with time-dependent Schrödinger equation and strong-field approximation.
• Validated the accuracy of the GTO-based TD-DFT approach for ionization dynamics.

Conclusions:

• The developed tuned DFT with GTO method enables predictive all-electron TD-DFT simulations.
• This approach is suitable for studying ionization and ionization-triggered dynamics in molecular systems.
• Tuned range-separated hybrid functionals enhance the accuracy of ionization modeling.