EStokTP: Electronic Structure to Temperature- and Pressure-Dependent Rate Constants-A Code for Automatically...

Area of Science:

• Computational Chemistry
• Chemical Kinetics
• Theoretical Chemistry

Background:

• Accurate a priori rate predictions for gas-phase reactions are crucial for understanding chemical processes.
• Current computational methods often achieve accuracy comparable to experimental data.
• Implementing these predictions for numerous systems remains challenging due to significant human effort.

Purpose of the Study:

• To develop a computational environment, EStokTP, that minimizes human effort in predicting reaction rates.
• To enable efficient, high-accuracy kinetic predictions for large sets of chemical reactions.
• To provide a fully integrated workflow for both electronic structure and kinetic calculations.

Main Methods:

• EStokTP integrates electronic structure calculations with kinetic solvers, such as transition state theory (TST)-based master equation solvers.
• The environment automates the generation, extraction, and organization of structural properties from electronic structure codes.
• Implements advanced theoretical treatments including hindered rotor models, Eckart and small curvature tunneling, and variational methods.

Main Results:

• EStokTP significantly reduces the human effort required for predicting rate constants of single-channel reactions.
• The code successfully generates necessary master equation building blocks for complex reaction systems.
• Demonstrated application to studies involving hundreds of abstraction, addition, isomerization, and beta-decomposition reactions.

Conclusions:

• EStokTP offers a robust and efficient platform for high-accuracy theoretical studies of chemical reaction rates.
• The automated workflow facilitates the application of advanced TST methods to large-scale reaction datasets.
• Preliminary protocols for barrierless and multi-well/multi-channel reactions show potential for broader applicability.