Work

Microcanonical Rate Constants With Rice–Ramsperger–Kassel–Marcus in Eyringpy

Year: 2025

Type: article

Abstract: ABSTRACT Rice–Ramsperger–Kassel–Marcus (RRKM) theory was implemented in Eyringpy to enable the computation of microcanonical rate constants, densities of states (DOS), and sums of states. Input can be provided either as experimental data or directly from electronic‐structure output files, requiring minimal user specification. The Stein–Rabinovitch algorithm was employed for accurate state counting, and tunneling corrections were introduced through the Eckart model to account for light‐particle transfer and narrow barriers. To validate the implementation, the DOS of hydrogen peroxide was evaluated with anharmonic‐vibrational corrections, and three gas‐phase reactions were analyzed: thermal decomposition of digermane, bromine‐atom loss from CH 2 BrO·, and hydrofluoric‐acid elimination from CF 3 CH 3 . The validation confirms that Eyringpy provides accurate and efficient RRKM calculations, providing reliable kinetic analyses of unimolecular reactions across a broad energy range.

Source: Journal of Computational Chemistry

DOI: 10.1002/jcc.70259

Authors: Aura Gómez‐Heredia, Eugenia Dzib, Gabriel Merino

Institution: Universidad Autónoma Metropolitana

Language: English

Topic: Advanced Physical and Chemical Molecular Interactions

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: hybrid

Estimated APC paid: $4,520

Funders: Instituto Politécnico Nacional, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional