Phase Diagrams
Thermodynamic stability analysis with convex hull computation for binary, ternary, and quaternary systems.
Source: src/lib/phase-diagram/
Overview
Phase diagrams show the thermodynamic stability of compounds in a chemical system. CatGo computes convex hulls to determine:
- Which compositions are thermodynamically stable
- Energy above hull (instability measure) for metastable phases
- Decomposition pathways for unstable compounds
Components
| Component | Description |
|---|---|
PhaseDiagram2D.svelte | Binary (A-B) and ternary (A-B-C) 2D phase diagrams |
PhaseDiagram3D.svelte | 3D convex hull visualization |
PhaseDiagram4D.svelte | Quaternary (4-component) compositional space |
PhaseDiagramControls.svelte | Legend, color scale, and display options |
PhaseDiagramInfoPane.svelte | Stability information for selected point |
PhaseDiagramStats.svelte | Statistics summary |
Key Functions
typescript
// Compute thermodynamic convex hull
compute_convex_hull(entries): ConvexHull
// Calculate energy above hull for each entry
compute_e_hull(entries, hull): number[]
// Sort/filter entries by composition
sort_entries_by_composition(entries): SortedEntries
// Convert to barycentric coordinates (for ternary diagrams)
barycentric_coords(composition): [number, number]
// Full thermodynamic analysis
thermodynamic_analysis(entries): ThermodynamicResultDiagram Types
Binary (2D)
- x-axis: composition fraction (A to B)
- y-axis: formation energy (eV/atom)
- Convex hull line connects stable phases
- Points above hull are metastable/unstable
Ternary (Triangle)
- Three vertices represent pure elements
- Interior points are compositions
- Color-coded by energy above hull
- Tie lines connect stable phases
3D / Quaternary
- 3D convex hull surface
- Interactive rotation for 4-component systems
- Projection views available
Features
- Color-coded stability — stable (on hull) vs metastable (above hull)
- Interactive selection — click points to see composition details
- Structure preview — hover to preview crystal structure
- Energy above hull — quantitative instability measure (meV/atom)
- Decomposition info — shows which stable phases an unstable compound would decompose into