page last updated: 22.07.2016

Dataset 6

This page contains information and downloads pertaining to the Holland and Powell (2011) internally-consistent thermodynamic dataset. This dataset has evolved since the publication of that paper and is now at version 6.2.


a-x files and software

Currently, there are only limited a-x relations available for use with the new dataset. Existing DS55 era a-x models are not appropriate for use with the new dataset as many aspects of them are incompatible with the new thermodynamic data. This is especially true for any phase that has a "made" endmember or a DQF adjustment. Likewise, the DS6 models available here should not be used with the older dataset. A new set of models for metapelites in NCKFMASHTO is now available in the download below. The a-x models here are from:

White, R.W., Powell R., Holland T.J.B., Johnson T.E. & Green, E.C.R. New mineral activity--composition relations for thermodynamic calculations in metapelitic systems. Journal of Metamorphic Geology, submitted.

with the model for sapphirine from:

Wheller, C. & Powell, R. 2013. A new thermodynamic model for sapphirine: calculated phase equilibria in K2O-FeO-MgO-Al2O3-SiO2-H2O-TiO2-Fe2O3. Journal of Metamorphic Geology, submitted.

The White et al paper uses the methodology outlined in:

Powell R., White, R.W., Green, E.C.R., Holland T.J.B., & Diener, J.F.A. On generating activity-composition relations of minerals for petrological calculations. Journal of Metamorphic Geology, submitted

Hopefully, these papers will be available online relatively soon.

Download latest versions

The dataset download is a zipped bundle containing the following files: THERMOCALC 3.40 (mac & PC), tc-ds62, tc-6NCKFMASHTO, tc-6KFMASHTO, tc-6KFMASH, several example script files, finished diagrams for each script file, drawpd 1.16 (mac & PC) and several example drawpd input files.

Download Mac version

Download PC version

Download MnNCKFMASHTO files

Below you can download the a-x files for the new Manganese models. The files should work for both mac and PC

Download MnNCKFMASHTO files

Download deep mantle files

Below you can download the a-x files for the new deep mantle models from Holland et al 2013 - New Thermodynamic Models and Calculated Phase Equilibria in NCFMAS for Basic and Ultrabasic Compositions through the Transition Zone into the Uppermost Lower Mantle (J Petrol 2013, 54, 1901-1920).




Download mantle melting files

Below you can download the a-x files for the new mantle meltingmodels from Jennings, E. S. and Holland, T. J. B. (2015) A Simple Thermodynamic Model for Melting of Peridotite in the System NCFMASOCr. Journal of Petrology, 56 (5). pp. 869-892.

all files

Download metabasic melting files

Below you can download the a-x files for the new mantle meltingmodels from Green et al. (2016) Activity–-composition relations for the calculation of partial melting equilibria in metabasic rocks. Journal of Metamorphic Geology.

The download includes the latest versions of THERMOCALC (tc340 & tc345) and drawpd (version 1.17). We recommend you use tc345. There are two "read me" files included, one outlines aspects of the models and the other outlines some new facilities in THERMOCALC and drawpd.

PC users, please note: on a small number of pcs running various versions of windows drawpd116 and drawpd117 would not work–we have no idea why. If this happens to you, you will need to use drawpd115 instead

Download Mac version

Download PC version


DS6 Release Notes

The dataset in the ds6 paper:

Tim Holland & Roger Powell, 2011. An improved and extended internally consistent thermodynamic dataset for phases of petrological interest, involving a new equation of state for solids. Journal of Metamorphic Geology, 29, 333-383

is designated to be tc-ds60.txt, and this will not be released for use. The dataset released here, designated tc-ds61.txt, includes important changes to, and improvements on, tc-ds60.txt as noted here. The new THERMOCALC release, tc336, should be used with the file tc-ds61.txt. Those using this updated dataset should refer to it as "using an updated version of the Holland & Powell 2011 dataset (ds61, September 2011).

As noted here previously, the transition from tc-ds55.txt to tc-ds61.txt is non-trivial for all concerned, including you the user. Much has changed. For those of you who are mid-project it is not wise to think of jumping to the new dataset unless there is something specifically in the new dataset that will dramatically improve your modelling. The dataset, tc-ds55.txt, and accompanying axfiles have been widely used and are considered to be quite stable, as well as being good at reliably modelling the majority of rocks. So keeping on using tc-ds55.txt is your best plan for projects already started.

For use with the new dataset, many of the existing activity-composition relationship codings in axfiles will need to be modified, mainly because the underlying assumptions in dataset generation have changed substantially in the intervening 8 years between tc-ds55.txt and tc-ds61.txt. The existing ds55-generation axfiles should NOT be used with tc-ds61.txt as this will in most cases result in erroneous results (e.g. with biotite, amphibole, melt). There are other codings (e.g. chlorite, cordierite) that we are taking this opportunity to upgrade because the current ones, for various reasons, are obsolete. Our aim, of course, is to make these new axfiles as stable and reliable as the old ones. Clearly this is a big job - one that we are working hard on - so please be patient and await their release here. Of course, in the mean time you can use tc336 for calculations on end-members with tc-ds61.txt (e.g. with modes 0 and 3) to look at the new dataset. (This version of THERMOCALC is fully backwards compatible and is the version we recommend for use for all calculations now).

To provide a perspective on the above, remember that doing calculations with THERMOCALC (or other calculation software) involves an internally-consistent thermodynamic dataset providing the thermodynamic properties of the end-members of phases, like tc-ds61.txt, AND the activity-composition relationships of the phases representing the energetics of the combination of the end-members into phases (in axfiles). Undoubtedly the new dataset, tc-ds61.txt, provides a huge leap forward in terms of the thermodynamics of end-members, as spelt out in Holland & Powell (2011) (above). Much new experimental information and methodology has become available and been incorporated in the new dataset, even since tc-ds55.txt (November 2003, but solidly based on Holland & Powell, 1998). Because of this it is not an option into the future, for example for new projects once the new axfiles are released, to use tc-ds55.txt (or as some people continue to do, use even older datasets)