Simulating Real-Time Molecular Electron Dynamics Efficiently Using the Time-Dependent Density Matrix Renormalization...

Area of Science:

• Computational chemistry
• Quantum dynamics

Background:

• Simulating molecular real-time electron dynamics is computationally challenging compared to ground-state calculations.
• The time-dependent density matrix renormalization group (TDDMRG) offers a balance between accuracy and computational cost for electron dynamics simulations.
• Optimal selection of TDDMRG simulation parameters is crucial for reliable results, but guidelines are lacking.

Purpose of the Study:

• To investigate the convergence behavior of key TDDMRG simulation parameters.
• To develop a guideline for choosing TDDMRG parameters.
• To propose an orbital selection method for optimizing dynamics simulations.

Main Methods:

• Investigated convergence of time integrators, orbital choices, and matrix-product-state representations for complex-valued nonsinglet states in TDDMRG.
• Developed a tailored orbital selection method to enhance dynamics simulation accuracy.
• Applied TDDMRG to study charge migration ionization dynamics in furfural.

Main Results:

• Established a guideline for selecting TDDMRG simulation parameters.
• Demonstrated a rapid charge migration and ionization in furfural within a femtosecond.
• Observed a σ to π character conversion in the ionized state of furfural.

Conclusions:

• The developed guidelines improve the quality and efficiency of TDDMRG simulations.
• TDDMRG is a powerful tool for studying ultrafast electron dynamics.
• The study provides insights into charge migration mechanisms in molecules like furfural.