Electron Dynamics with the Time-Dependent Density Matrix Renormalization Group.

Area of Science:

• Quantum chemistry
• Computational physics
• Molecular dynamics

Background:

• Simulating electron dynamics is crucial for understanding molecular behavior.
• Traditional methods struggle with complex, time-dependent quantum systems.
• Accurate modeling requires efficient algorithms for large electron-orbital configurations.

Purpose of the Study:

• To develop and apply a computational framework for simulating electron dynamics.
• To leverage the tangent-space TD-DMRG formulation for enhanced accuracy.
• To investigate phenomena challenging for time-independent methods.

Main Methods:

• Utilized the time-dependent density matrix renormalization group (TD-DMRG) algorithm.
• Employed a matrix product state parametrization for the wave function.
• Developed a computational framework driven by the exact nonrelativistic electronic Hamiltonian.

Main Results:

• Successfully simulated electron dynamics for systems up to 20 electrons and 32 orbitals.
• Accurately calculated molecular (hyper)polarizabilities.
• Simulated electronic absorption spectra and ultrafast ionization dynamics.

Conclusions:

• The TD-DMRG algorithm provides a powerful tool for studying complex molecular dynamics.
• This computational framework extends the reach of quantum simulations to previously inaccessible problems.
• The method opens new avenues for theoretical investigations in molecular science.