The effect of sampling techniques used in the multiconfigurational Ehrenfest method

Area of Science:

• Quantum chemistry
• Computational chemistry
• Photochemistry

Background:

• The ab initio multiple cloning method (AMCM) is a powerful tool for quantum simulations.
• Direct dynamics extensions are crucial for simulating ultrafast photochemical processes.
• Accurate basis set sampling is essential for reliable quantum dynamics simulations.

Purpose of the Study:

• To compare and contrast novel basis set sampling techniques for AMCM.
• To evaluate the efficacy of simultaneous basis set cloning and basis function trains.
• To assess the convergence of these methods towards exact quantum results.

Main Methods:

• Application of basis set cloning and basis function trains within AMCM.
• Quantum simulation of dynamics in the spin boson model.
• Comparison of simulation results against accurate benchmarks.

Main Results:

• Simultaneous use of basis set cloning and basis function trains yields results converged to the exact quantum solution.
• The sampling methods demonstrate accuracy across a broad range of spin boson model parameters.
• Validated the effectiveness of the developed sampling techniques for quantum dynamics.

Conclusions:

• The combined basis set cloning and basis function train approach provides a robust method for accurate quantum simulations.
• These techniques significantly advance the capabilities of direct dynamics extensions for studying ultrafast photochemistry.
• The developed methods offer a pathway to highly accurate quantum simulations in complex chemical systems.