Development of a Conformational Sampling Method for Transition State Structures With Diverse Active Bond Lengths
Satoshi Matsutani1, Taichi Shomura1, Nobuya Tsuji2
1Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, Japan.
Journal of Computational Chemistry
|August 7, 2026
Summary
TStrail is a new computational tool that automatically generates diverse transition state (TS) conformers by exploring various reactant configurations. This method overcomes limitations of fixed bond lengths, enabling more comprehensive TS conformational sampling for complex chemical reactions.
Area of Science:
- Computational Chemistry
- Chemical Reaction Dynamics
- Molecular Modeling
Background:
- Transition state (TS) conformer identification is crucial for understanding reaction mechanisms.
- Conventional methods often fix bond-forming/breaking distances, potentially limiting the diversity of sampled TS conformers.
- Variations in active bond lengths among conformers can be significant, especially in complex systems.
Purpose of the Study:
- To introduce TStrail, a novel computational tool for automated transition state (TS) conformational sampling.
- To overcome the limitations of fixed active bond lengths in traditional TS searching methods.
- To enable the generation of a comprehensive set of TS conformers, including those with varying active bond lengths.
Main Methods:
- TStrail performs collective pathway searches across various reactant conformations.
- It automatically generates TS conformers without pre-fixing the bond forming/breaking distance.
- The tool was applied to analyze complex molecular systems.
Main Results:
- TStrail successfully generated TS conformers with diverse active bond lengths.
- The tool demonstrated practicality in systematically analyzing challenging TS conformers.
- Applications to complex systems, including large, flexible, and ionic molecules, were successful.
Conclusions:
- TStrail provides a practical and systematic approach for comprehensive TS conformational sampling.
- The tool enhances mechanistic insights by identifying diverse TS conformers and reaction pathways.
- TStrail is particularly valuable for studying structurally complex and flexible transition states.
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