This is the index page for getting help with THERMOCALC: specifically, how to make it do the calculations you want. If your question is something like “What types of calculation can I do with THERMOCALC?”, “How do I use THERMOCALC to calculate a phase diagram,” or “What is a THERMOCALC scriptfile and where do I get one?”, then you’re in the right place.

Alternatively, if you’re wondering what a pseudosection is and why people calculate them, try the resources on computational phase equilibrium in geoscience. If you’re interested in the modelling of thermodynamic data that underlies THERMOCALC (the HPx-eos or Holland and Powell dataset), or you’re worried because your calculations in THERMOCALC or Perple_X produce results that are very different from your rock, then you probably need the section on the HPx-eos.

On this page:

Starting THERMOCALC for the first time

The Get started guide will help you get THERMOCALC running on your computer.

We’d strongly recommend that you know what the HPx-eos are, and have read about their use and their limitations, before getting started on calculations.

Did you plan to use THERMOCALC for phase diagram calculations, but you now feel lost and unsure about both THERMOCALC and phase diagrams? If so, we suggest looking at Simon Schorn’s series of tutorials that link together P-T projections, compatibility diagrams and pseudosections, with calculations in THERMOCALC 3.50. You can find these in the Tutorials sections for the three different types of calculation, following the links above.

Information on specific calculation facilities

THERMOCALC has several facilities for doing different types of calculation, as listed below. You can find information specific to the various facilities, including user instructions, tutorials and documentation, by following the links:

General documentation

Some useful documents are provided below, which are “general” insofar as they apply to more than one of the calculation facilities. Documentation for specific calculation types is provided on the specialist webpage for that facility. We may add to the following list over time in response to user questions:

1) Composition spaces and phases in THERMOCALC

Perhaps the most important piece of THERMOCALC documentation available, the following notes explain compositional and order variables within phases, how to set the bulk composition and interpret the modal proportions of minerals and fluids correctly, setting phases “in excess”, solvus calculations and more. (current Dec 2020):

2) Lecture slides by Roger Powell from a THERMOCALC short course (São Paulo, Brazil, 2006). These focus on phase diagram calculations and multiple-reaction thermobarometry, but give a useful feeling for the philosophy behind THERMOCALC.

3) A further short pdf from RP, on the background to THERMOCALC’s development.

4) New users might be interested in the following, for getting started with any kind of phase diagram calculation:

A handy guide to troubleshooting phase diagram calculations in THERMOCALC – for complete beginners; includes THERMOCALC error exit codes (current Dec 2020):

Richard White & Johann Diener’s series of phase diagram tutorials (just the pdfs, as their input files and software are now out of date):

5) Scripts for controlling THERMOCALC

In THERMOCALC 3.50 from Dec 2020 onwards: A summary of new scripts, mainly related to mode 1 (forward modelling) calculations, can be found here:

In THERMOCALC 3.47 and older: Two lists of scripts that can be used to fine-tune calculations in various facilities, replacing interactive prompts. Both lists are now very old. Many scripts have been added since, and some have ceased to exist because their functionality has been incorporated into another approach (or even deemed unsound). However, they should be a useful starting point. For more ideas on scripting, see the tutorials and example scriptfiles for the individual calculation facilities, or ask the discussion group if you feel something should be available that you can’t see.

Find out more

Users and potential users of THERMOCALC are welcome to join our discussion group.

If your problem relates to a possible bug in THERMOCALC, you’ll need to send full input and output files from your calculation, preferably fully scripted so that we can see the problem with one click, or alternatively with a description of the calculation you were doing. Please post these files in a message to the discussion group, or send them to Eleanor Green via her University of Melbourne email address (easily discoverable).