University of MichiganAnn Arbor, MI 48109-2143

Climate and Space Sciences and Engineering

MultiWell Program Suite

J. R. Barker, T. L. Nguyen, J. F. Stanton, C. Aieta, M. Ceotto,
F. Gabas, T. J. D. Kumar, C. G. L. Li, L. L. Lohr, A. Maranzana,
N. F. Ortiz, J. M. Preses, J. M. Simmie, J. A. Sonk, and P. J. Stimac


This is the MultiWell web site. Contact John R. Barker at for further information or to be added to the email list.


1. MULTIWELL: WINDOWS version: The WINDOWS version of the master equation code was recompiled using a smaller array length for the number of reaction channels allowed for each well (now 49 elements). If a User needs to use more channels, then the LINUX version must be employed.


1. MULTIWELL: Enhancement: Previously, a feature was introduced for adding supplementary bimolecular reactions (keyword BIMOLRXN). This feature has now been enhanced to also include adding supplementary first-order reactions and the keyword has been replaced with MORERXN. The rate constants are expressed with in Arrhenius form: ksupp(T) = Afc × exp(–Bbm / T), where T is the translational temperature and Afc and Bbm are parameters. This feature is useful for reaction rate constants that do not have significant dependence on the internal energy of the Well (i.e. k(E) is approximately constant, as in the work of Matthias Oltzmann (2002)). When the energy dependence cannot be neglected, the MORERXN option should not be used, but the microcanonical k(E) should instead be computed and entered as an external RKE type file, as described in the User Manual.

2. pTS: New Parallel Version: A true parallel version of the TS master equation code has been contributed by Lam Nguyen and John Stanton as an alternative to the serial version, which was already available on the website. This parallel version, pTS, can be compiled either by IFORT (Intel compiler) or by GFORTRAN and will run on Macintosh (including MacBook Pro) and HP computers using openMPI. The code package includes documentation.

3. BDENS and DENSUM: Bug fix: A bug (reported by Nadav Genossar) in the subroutine for symmetrical hindered rotors consisted of a do-loop taking an extra step. This bug has been fixed. Its effect on output is not known, but seems to be relatively small.

4. PARADENSUM and PARSCTST: Bug fix: A bug in the hindered rotor subroutines caused the codes to produce a null output. This did not affect output when the hindered rotor option was not selected. This bug has been fixed. The effect on users was minimal.

5. MultiWell User Manual: Updated for v.2021.