A multi-layer energy-based fragment method for excited states and nonadiabatic dynamics

Area of Science:

• Computational Chemistry
• Theoretical Chemistry
• Quantum Chemistry

Background:

• Accurate simulation of photochemical processes is crucial for understanding chemical reactions.
• Simulating large molecular systems with high accuracy remains computationally challenging.
• Existing methods often struggle to balance accuracy and computational cost for complex systems.

Purpose of the Study:

• To develop a novel computational method for accurate and efficient simulation of photochemical dynamics.
• To introduce the multi-layer energy-based fragment (MLEBF) method within the many-body energy expansion framework.
• To assess the accuracy and efficiency of MLEBF for excited-state properties and nonadiabatic dynamics.

Main Methods:

• Development of the multi-layer energy-based fragment (MLEBF) method.
• Implementation within the many-body energy expansion (MBE) theoretical framework.
• Application to nonadiabatic dynamics simulations and excited-state property calculations.

Main Results:

• The MLEBF method provides accurate energies and gradients for molecular systems.
• It accurately reproduces excited-state topological structures.
• MLEBF-based nonadiabatic dynamics simulations closely match results from full ab initio calculations.

Conclusions:

• The developed MLEBF method offers a computationally efficient and accurate approach for photochemical simulations.
• This work paves the way for studying the photochemistry of larger and more complex molecular systems.
• MLEBF has the potential to significantly advance the field of theoretical photochemistry.