Time-dependent quantum chemistry of laser driven many-electron molecules

Area of Science:

• Quantum Chemistry
• Theoretical Chemistry
• Computational Physics

Background:

• Recent development of a Time-Dependent Configuration Interaction approach with multiple Feshbach partitionings for laser-driven molecules.
• Need for fully ab-initio methods to calculate time-dependent electronic wavefunctions for N-electron molecules.

Purpose of the Study:

• To adapt multiconfiguration quantum chemistry tools, specifically Graphical Unitary Group Approach concepts, for time-resolved electronic dynamics.
• To develop a method for calculating time-dependent electronic wavefunctions in molecules subjected to intense laser fields.

Main Methods:

• Adaptation of multiconfiguration quantum chemistry tools (Graphical Unitary Group Approach) to time-resolved electronic dynamics.
• Application of the Time-Dependent Configuration Interaction approach with multiple Feshbach partitionings.
• Calculation of electronic dynamics for BeH2 using a specific basis set augmented with continuum-type orbitals.

Main Results:

• Detailed, sub-cycle electronic dynamics of BeH2 were calculated under intense continuous-wave laser fields (800 nm and 80 nm).
• The dynamics exhibited strong non-linearity at field intensities around 10^15 W/cm^2.
• Significant ionization of inner-shell electrons and complex post-ionization dynamics of bound electrons were observed.

Conclusions:

• The adapted methods provide a powerful tool for simulating time-dependent electronic wavefunctions in laser-driven molecules.
• The study highlights the complex non-linear electronic dynamics occurring in molecules under intense laser irradiation.
• This approach advances the capability for ab-initio calculations of ultrafast molecular processes.