This utility uses the qhull algorithm to create phase diagrams for arbitrary regions of phase space. Depending on the dimensionality of the requested phase diagram, different plots are made.
2-D phase diagrams, we produce the convex hull
3-D phase diagrams we give create the Gibbs' triangle
4-D phase diagrams, an isometric shot of the Gibbs tetrahedron
Higher-order phase diagrams, we create a graph depiction of the phase equilibria data. In these plots, every line corresponds to 2-phase equilibrium.
Formation energies
The formation energies supplied to this tool were calculated using elemental reference states which are a combination of DFT total energies of elemental phases, fit to experimental formation energies (the gases, and ionic solids), corrected to remove the effects of DFT+U.
References
1. Barber, C., Dobkin, D. & Huhdanpaa, H. The quickhull algorithm for convex hulls. ACM Transactions on Mathematical Software 22, 469–483 (1996).
2. Stevanović, V., Lany, S., Zhang, X. & Zunger, A. Correcting density functional theory for accurate predictions of compound enthalpies of formation: Fitted elemental-phase reference energies. Physical Review B 85, 115104 (2012).