Ternary

Ternary is a new free energy visualization tool. Inspired by Craig Carter's Mathematica scripts for binary mixtures, it uses qhull to calculate the convex hull of the free energy curve, and visualizes the result including two-phase tie lines and three-phase triangles. For multiple phases, such as the situation to the right, visualizing their intersection is tricky, but the principle is the same: the convex hull gives the minimum energy surface.

This consists of two libraries: libfreenergy and libgibbs, and two example C-codes: ternary (output shown) and square. The libfreenergy library computes free energies and their derivatives, and can be shared with phase field software, which uses free energies as a starting point. The libgibbs library includes the rest of the phase diagram isotherm calculation infrastructure.

To build: in the ternary directory, type:

./configure; make

To build the documentation, type:

make stamp-doc

Building ternary requires Geomview and Qhull. Building the documentation uses Cxref, LaTeX, and HeVeA and/or LaTeX2HTML.

Browse the source code

Plans for Ternary

The 2-D projection of the convex hull is the phase diagram at a single temperature.

Later versions will:

• Calculate the whole temperature-dependent ternary phase diagram
• Use sliders to manipulate free energy parameters
• Visualize changes to the free energy and phase diagram in real time

In other words, the goal is to be a ternary version of what Craig Carter's Mathematica scripts do for binaries.

Other thermodynamics visualization sites

• Kenneth Jolls' website on Gibbs model visualizations