ORCHID

Version 1, machine-extracted: values were read by language-model readers constrained to quote their source and checked automatically, and the release was then audited on the printed pages by adversarial audits, an independent second review of fit-facing records and a preliminary human review of a frozen sample. Flags such as accepted and ESPEI-ready record screening results, not certification; known issues are listed in the release notes.

open-tdb / hull lab

Binary formation and mixing thermodynamics

Hulls and mixing curves, one axis.

Overlay the 298.15 K CALPHAD hull, the 0 K Materials Project and OQMD hulls, and the Redlich-Kister mixing curves of every bundled assessment against composition; trace any two source–quantity pairs against each other; or scatter one precomputed scalar against another across every binary.

ΔH_f is the one axis all three layers shareA 0 K DFT hull is a formation energy of ordered structures; a CALPHAD hull is a Gibbs energy at 298.15 K with ΔH_f read along it; a mixing curve is one phase against its own endmembers. The legend names each zero and every conversion.

Plot type

Sources CALPHAD hull · 298.15 K DFT hull · Materials Project · 0 K DFT hull · OQMD · 0 K Redlich-Kister mixing

DFT hulls carry enthalpy only; selecting Gibbs energy or entropy leaves them out and says so in the subtitle.

Quantity

Overlays Hull vertices (hollow = theoretical) DFT above-hull entries (× theoretical) ±1.45 kJ/mol-atom band on DFT hulls CALPHAD assessment spread ribbon

Markers draw below 400 curves and above-hull entries below 200; the ribbon needs two or more visible assessments of one system.

Temperature · mixing curves

Applies to Redlich-Kister curves only. Hull layers are pinned at 298.15 K (CALPHAD) and 0 K (DFT).

Element filter

Fixes the selected element at x = 0; every curve then uses the mole fraction of its other element.

System search

An exact binary such as Fe-C selects that system in either order.

Flag filter

A system passes when any of its documents in any layer carries the flag.

Preferred assessment only Only systems present in every selected source

0objects drawn

0binary systems

Enthalpy

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visible y range

Explore

Hover a curve to emphasize it and read its phases, tie-line, or active Redlich-Kister expressions. Drag a rectangle to zoom; click without dragging to hide a curve and rescale. Filter to one binary to open the phase-by-composition table.

What is not being claimed

A 0 K ordered-structure hull has no representation for a disordered solution; where a CALPHAD single-phase curve bows below a straight DFT tie-line, that is a limit of one representation, not a disagreement between two claims. Assessments of one system differ and are never averaged here.

Matching objects

System	Source	Assessment	Details	Files	Plot

Generated deterministically from catalog/catalog.json (), hulls/calphad-sgte/catalog.json (), hulls/dft-mp/catalog.json (), and hulls/dft-oqmd/catalog.json (): 2,695 CALPHAD assessments over 1,223 systems, 3,828 Materials Project and 3,916 OQMD systems, 2,552 Redlich-Kister databases. Comparative screening views, not phase-equilibrium results or validation of any assessment.