Development of Parallel On-the-Fly Crystal Algorithm for Reaction Discovery in Large and Complex Molecular Systems

Area of Science:

• Computational Chemistry
• Chemical Dynamics
• Molecular Modeling

Background:

• Exploring potential energy surfaces and conical intersections is crucial for understanding molecular reactions.
• Applying global search algorithms to complex systems, especially in condensed phases, presents significant computational challenges due to high dimensionality.

Purpose of the Study:

• To extend the applicability of the parallel on-the-fly Crystal algorithm to reaction discovery in large, complex molecular photoswitches.
• To investigate the influence of molecular environments, including explicit solvent, on reaction pathways.

Main Methods:

• Developed an enhanced Crystal algorithm for explicit exploration of configurational subspaces in complex molecules.
• Implemented an automated workflow for reaction discovery and characterization in vacuum and aqueous solutions.
• Applied the algorithm to study bilirubin and donor-acceptor Stenhouse adducts.

Main Results:

• Successfully applied the Crystal algorithm to discover and characterize new minima and low-energy reaction pathways in complex photoswitches.
• Demonstrated the algorithm's efficiency in exploring configuration space and identifying kinetically accessible products.
• Provided insights into the role of molecular environments on reaction pathways.

Conclusions:

• The enhanced Crystal algorithm effectively addresses challenges in exploring complex molecular systems, including condensed phases.
• The findings highlight the potential of parallelized global exploration methods for reaction discovery in biomolecular systems.
• This work offers new perspectives on the reactivity of molecular photoswitches and environmental effects.