Semiclassical Nonadiabatic Molecular Dynamics Using Linearized Pair-Density Functional Theory.

Area of Science:

• Computational Chemistry
• Theoretical Chemistry
• Quantum Chemistry

Background:

• Nonadiabatic molecular dynamics is crucial for studying excited-state molecular processes.
• Accurate potential energy surfaces and efficient electronic structure methods are vital for reliable simulations.
• Existing methods often face trade-offs between accuracy and computational cost.

Purpose of the Study:

• To integrate Linearized Pair-Density Functional Theory (L-PDFT) with nonadiabatic dynamics simulations.
• To assess the accuracy and efficiency of L-PDFT for modeling photochemistry.
• To investigate the photoisomerization of cis-azomethane using this novel approach.

Main Methods:

• Integration of the SHARC dynamics code with the PySCF electronic structure package.
• Utilization of L-PDFT, a multireference method, for calculating potential energy surfaces.
• Direct dynamics simulations of the cis-azomethane photoisomerization reaction.

Main Results:

• L-PDFT was successfully implemented for nonadiabatic calculations.
• Simulations of cis-azomethane photoisomerization proceeded without computational failures.
• Results obtained with L-PDFT closely matched those from more computationally expensive methods like extended multistate complete active space second-order perturbation theory.

Conclusions:

• L-PDFT provides a computationally efficient yet accurate approach for modeling potential energy surfaces in excited-state dynamics.
• The method effectively captures internal conversion processes.
• L-PDFT shows significant potential for advancing broader applications in molecular photodynamics.