Welcome to the AIOMFAC website

This website is designed to provide access to the thermodynamic model AIOMFAC in the form of an interactive web application and to provide supporting information.

News and latest changes ↑Top

This section lists important events and changes related to AIOMFAC-web in reverse chronological order.

  • April 23, 2024: AIOMFAC-web model update to v3.10. This version update is based on the corresponding updated Fortran code release on https://github.com/andizuend/AIOMFAC and fixes an incorrect middle-range interaction parameter that was present in v3.01–v3.05. The incorrect parameter affected activity coefficient calculations of mixtures containing H+ and organics with ether, hydroperoxide and/or peroxide functionalities. We thank Florian Couvidat for reporting this issue.

  • June 19, 2023: AIOMFAC-web model update to v3.05. This minor version update fixes a bug introduced with v3.04, which slightly affected activity coefficient calculations of mixtures containing organics with secondary hydroxyl functional groups. We thank Darren Rowland for noticing this and for informing us.

  • March 18, 2023: AIOMFAC-web model update to v3.04. This minor version update fixes a bug introduced with v3.03, which affected only the output of molalities reported for water and organic species as well as the individual mole fractions of ions (other outputs, such as activity coefficients and activities, were not affected). We thank Thomas Preston for notifying us about this issue.

  • February 11, 2022: AIOMFAC-web model update to v3.03. This minor version update adds support of AIOMFAC-VISC viscosity calculations for systems involving carbonate, bicarbonate and IO3-.

  • December 9, 2021: AIOMFAC-web model update to version 3.01. This major version update provides a number of new features.
    (1) Based on the work by Hang Yin et al.: additions of new inorganic species (ions I-, IO3-, HCO3-, CO32-, OH- and aqueous CO2) supporting calculations involving iodine species and the CO2(aq)–bicarbonate–carbonate system, including solving the dissociation equilibria (and associated effects on pH). Other ion–organic interaction parameters were also updated; for details see the article by Yin et al. (2022).
    (2) Based on the work by Lilek and Zuend: viscosity calculations of aqueous electrolyte mixtures as well as mixed organic–inorganic phases have been introduced; for details see the article by Lilek and Zuend (2022). This addition is a major update of the AIOMFAC-VISC model within AIOMFAC-web, substantially enhancing the range of applicability. See the Hints & Examples page for more information.
    Additional notes on underlying source code updates are provided at https://github.com/andizuend/AIOMFAC.

  • July 18, 2020: AIOMFAC-web model update to version 2.32. This version provides added selection choices for UNIFAC's primary and secondary amine groups, as well as nitro groups. However, these functional groups are currently only supported for electrolyte-free systems.

  • September 26, 2019: AIOMFAC-web model update to version 2.31. The underlying model code has been updated to resolve an issue with systems of a large number of components, introduced with the previous version, resulting in faster model execution speed. Also, an issue on the McGill server when running the model via the upload of an input file has been fixed.

  • August 23, 2019: A new feature, the prediction of the dynamic viscosity of an aqueous organic mixture (phase) has been introduced with this update. The viscosity prediction uses the recently developed AIOMFAC-VISC model by Gervasi et al. (2019). See the Hints & Examples page for more information. The model was updated to version 2.30. This version update further includes new or updated AIOMFAC interaction parameters for the following cation–anion combinations: K+ ↔ SO42-, K+ ↔ HSO4-, Ca2+ ↔ HSO4-, Mg2+ ↔ HSO4-, and Li+ ↔ HSO4-.

  • January 23, 2019: A minor model update to version 2.21. A bug concerning input composition verification and a related error check have been fixed (no changes to actual AIOMFAC calculations).

  • August 13, 2018: Several changes were made to hardware, software and content of the AIOMFAC website.  (1) The website is now hosted permanently on a new server at McGill University, accessible via the following URL: https://aiomfac.lab.mcgill.ca. The previous, temporary server at McGill will redirect to this address. The Caltech-hosted website remains available.  (2) The contents of this page as well as the Hints & Examples page, previously listed as "Help" page, were updated.  (3) A new option on the "Run model" input form makes it possible to display the model results page in a new browser tab. This allows keeping the input form open for easier adjustments.  (4) AIOMFAC-web has been updated to version 2.20, which includes minor revisions and optimization of the code.  (5) For the adventurous: the Fortran source code of the AIOMFAC-web version 2.20 (and future updates) and supporting information is made availabe publicly via https://github.com/andizuend/AIOMFAC.

  • Archive of "News and latest changes".

Learn about the AIOMFAC model ↑Top

Use the navigation bar on top or the following link to learn more about AIOMFAC, its concept, development, and range of applications.

How to use AIOMFAC-web ↑Top

The model version made available online, termed AIOMFAC-web, allows the calculation of activity coefficients in organic-inorganic mixtures – from simple binary solutions to complex multicomponent systems.

The Hints & Examples page offers a step-by-step guide on how to use AIOMFAC-web, as well as useful information referring to the mode of calculation. Different examples of AIOMFAC-web calculations and related output analysis are described. In addition, you will find helpful information regarding model error and warning messages, browser compatibility, and technical problems.

Run the model ↑Top

Go directly to the model input form, enter the data for your system of interest and run the model.

Source code ↑Top

The Fortran source code of the AIOMFAC-web model (version 2.20 or newer) as well as supporting information are availabe publicly under a GNU GPL license v3.0 via https://github.com/andizuend/AIOMFAC.

Citation and references ↑Top

If you use results from AIOMFAC-web calculations for scientific publications or other forms of reports, please cite this website and the scientific articles describing the model as detailed here.

Check the list of references given at the end of About AIOMFAC and the information in the text on that page to find a number of sources describing the AIOMFAC model and its various applications reported in the scientific literature.

Acknowledgments ↑Top

Starting as the PhD thesis project of Andreas Zuend at ETH Zurich back in 2004, the AIOMFAC model has been under development for many years by now, involving a number of project partners. This website is one of the more recent products of that development process, with the goal of making the model available to the wider community. We are grateful for the financial support received from the following funding agencies, enabling the research and development of the AIOMFAC model and this website over the past 17+ years:

  – AIOMFAC model development

  • Swiss National Science Foundation (SNSF), project no. 200020-103651.
  • Swiss National Science Foundation (SNSF), project no. PA00P2_126227.
  • Competence Center Environment and Sustainability of the ETH Domain (CCES), project IMBALANCE.
  • Office of Science (SC, BER), US Department of Energy, grant DE-FG02-05ER63983.
  • US Environmental Protection Agency (EPA), STAR research assistance agreement RD-833749.
  • Electric Power Research Institute (EPRI).
  • ETH Zurich, Switzerland (ETHZ), research grant ETH-0210-1.
  • US National Science Foundation (NSF), grant AGS-1057183.
  • McGill University (Start-up Grant, A. Zuend)
  • Natural Sciences and Engineering Research Council of Canada (NSERC), grants RGPIN/04315-2014 and RGPIN-2021-02688.
  • Fonds de recherche du Qu├ębec – Nature et technologies (FRQNT), grant no. PR-286433.
  • Alfred P. Sloan Foundation (Chemistry of Indoor Environments) under prime award no. G-2020-13912 (MOCCIE).
  • The Government of Canada through the Federal Department of Environment and Climate Change (ECCC), grant no. GCXE20S049.

  – Website & Server Hardware

Future development and improvement of the AIOMFAC model and this website, as well as the maintenance of the technical infrastructure and services, will depend on funds available. If you would like to support our future projects financially or as a project partner, please contact us.

© 2012 – 2023 Andreas Zuend, California Institute of Technology | McGill University last page update: 2024-04-23