SS-QRRK Home Page

Latest version: 2019.01.10
Date of this version: Jan. 10, 2019


The SS-QRRK utility code is a program for calculating pressure-dependent rate constants using variational transition state theory. SS-QRRK) theory is an efficient way to incorporate variational effects, multidimensional quantum mechanical tunneling, and multi-structural torsional anharmonicity into the calculation of pressure-dependent rate constants in the falloff region of chemical reactions.

This utility is included in the Polyrate package, and users of that package do not need to obtain the program separately, but this Web suite allows one to obtain SS-QRRK without Polyrate.

SS-QRRK stands for System-Specific Quantum Rice-Ramsperger-Kassel. The method is described in:

See also for applying SS-QRRK for barrierless reactions:

SS-QRRK Documentation:

Licensing and downloading:

SS-QRRK - version 2019.01.10 is licensed under the Apache License, Version 2.0.
The manual of SS-QRRK - version 2019.01.10 is licensed under CC-BY-4.0.

Publications of results obtained with the SS-QRRK - version 2019.01.10 software should cite the program and/or the article describing the program.

No guarantee is made that this software is bug-free or suitable for specific applications, and no liability is accepted for any limitations in the mathematical methods and algorithms used within. No consulting or maintenance services are guaranteed or implied.

The use of the SS-QRRK - version 2019.01.10 implies acceptance of the terms of the licenses. The software may be downloaded here.

Links to other pages of interest:

This document last modified on Oct. 20, 2022
Updated by:  Software Manager