U system

47 accepted literature values from 9 paper(s) (experimental 9, model 23, unspecified 15); 0 calculated phase diagram(s). 15 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV.

Data: JSON · CSV · interactive explorer · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
experimental	9
model	23
unspecified	15

Accepted values by property group
Property group	Values
invariant reaction	4
phase transition	12
formation	5
heat capacity / entropy / enthalpy	8
crystal structure	18

Invariant reactions (literature)

Invariant reactions reported in the literature for the U system (4)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location
1408.15	other: L -> γU	L: U 1; γU: U 1	model	[1] Sheldon 1987	Table 1, p. 2, row 11 report
1049.15	polymorphic: γU -> βU	γU: U 1	model	[1] Sheldon 1987	Table 1, p. 2, row 12 report
942.15	polymorphic: βU -> αU	βU: U 1; αU: U 1	model	[1] Sheldon 1987	Table 1, p. 2, row 13 report
916	(β-U) -> (α-U) + (γ-U)	(β-U): U 0.987; (α-U): U 0.999; (γ-U): U 0.872	model	[2] Berche 2011	Table 3, p. 6, row 2 report

Formation enthalpies

Literature values in kJ/mol-atom where the per-atom basis is known. DFT columns: the lowest-energy entry at the same composition (Materials Project 2026.04.13, OQMD v1.8; different energy references, never averaged), from dft_parity.json.

Enthalpies of formation, U system (5)
Phase	Value	T (K)	Class	Source	Location
U (g)	533 kJ/mol-atom ± 8	298.15	model	[3] Guéneau 2002 cites Grenthe 1992	Table 4, p. 9, row 10 report
U (g)	534.996 kJ/mol-atom	298.15	model	[3] Guéneau 2002	Table 4, p. 9, row 9 report
α-U	0 kJ/mol-atom	298.15	model	[4] Beneš 2014	Table 1, p. 2, row 5 report
β-U	3.1661 kJ/mol-atom	298.15	model	[4] Beneš 2014	Table 1, p. 2, row 7 report
γ-U	9.5149 kJ/mol-atom	298.15	model	[4] Beneš 2014	Table 1, p. 2, row 9 report

Other properties

Phase transition (12)

Phase transition, U system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Phase transition	933.85 K	933.85	polymorphic: α→β alloy: U 1	experimental	[5] Mo 2021 cites Rai 2009 doi	Table 2, p. 6, row 6 report
Phase transition	933.85 K	933.85	polymorphic: α→β alloy: U 1	experimental	[5] Mo 2021	Table 2, p. 6, row 5 report
Phase transition	934.75 K	934.75	polymorphic: α→β alloy: U 1	experimental	[5] Mo 2021 cites Rai 2009 doi	Table 2, p. 6, row 7 report
Phase transition	935.15 K	935.15	polymorphic: α→β alloy: U 1	experimental	[5] Mo 2021 cites Rai 2009 doi	Table 2, p. 6, row 8 report
Phase transition	935.85 K	935.85	polymorphic: α→β alloy: U 1	experimental	[5] Mo 2021 cites Rai 2009 doi	Table 2, p. 6, row 9 report
Phase transition	937.65 K	937.65	polymorphic: α→β alloy: U 1	experimental	[5] Mo 2021	Table 2, p. 6, row 1 report
Phase transition	938.05 K	938.05	polymorphic: α→β alloy: U 1	experimental	[5] Mo 2021	Table 2, p. 6, row 4 report
Phase transition	939.15 K	939.15	polymorphic: α→β alloy: U 1	experimental	[5] Mo 2021	Table 2, p. 6, row 2 report
Phase transition	939.85 K	939.85	polymorphic: α→β alloy: U 1	experimental	[5] Mo 2021	Table 2, p. 6, row 3 report
Phase transition	941.15 K	941.15	α-U alloy: U 1	model	[6] Perron 2016 cites Dinsdale 1991 doi	Table 1, p. 3, row 12 report
Phase transition	1049.15 K	1049.15	β-U alloy: U 1	model	[6] Perron 2016 cites Dinsdale 1991 doi	Table 1, p. 3, row 13 report
Phase transition	1408.15 K	1408.15	γ-U alloy: U 1	model	[6] Perron 2016 cites Dinsdale 1991 doi	Table 1, p. 3, row 14 report

Heat capacity / entropy / enthalpy (8)

Heat capacity / entropy / enthalpy, U system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Entropy printed: S0 (298 K)	199.8 J/mol-atom/K	298.15	U (g) alloy: U 1	model	[3] Guéneau 2002	Table 4, p. 9, row 9 report
Entropy printed: S0 (298 K)	199.8 J/mol-atom/K ± 0.1	298.15	U (g) alloy: U 1	model	[3] Guéneau 2002 cites Grenthe 1992	Table 4, p. 9, row 10 report
Entropy printed: S0(298.15)	50.2 J/mol-atom/K	298.15	α-U alloy: U 1	model	[4] Beneš 2014	Table 1, p. 2, row 5 report
Entropy printed: S0(298.15)	53.385 J/mol-atom/K	298.15	β-U alloy: U 1	model	[4] Beneš 2014	Table 1, p. 2, row 7 report
Entropy printed: S0(298.15)	59.774 J/mol-atom/K	298.15	γ-U alloy: U 1	model	[4] Beneš 2014	Table 1, p. 2, row 9 report
Heat capacity printed: C0p (298 K)	23.69 J/mol-atom/K	298.15	U (g) alloy: U 1	model	[3] Guéneau 2002	Table 4, p. 9, row 9 report
Heat capacity printed: Cp0 (298 K)	23.69 per mol-atom ± 0.04	298.15	U (g) alloy: U 1	model	[3] Guéneau 2002 cites Grenthe 1992	Table 4, p. 9, row 10 report
Heat capacity printed: C0p (298 K)	23.69 J/mol-atom/K ± 0.04	298.15	U (g) alloy: U 1	model	[3] Guéneau 2002 cites Grenthe 1992	Table 4, p. 9, row 10 report

Crystal structure (18)

Crystal structure, U system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Lattice a	10.59 Å		βU alloy: U 1	model	[7] Moussa 2018 cites Massalski 1990	Table 1, p. 3, row 2 report
Lattice a	2.8537 Å	298.15	(αU) (αU): U 1	unspecified	[1] Sheldon 1987	Table 3, p. 3, row 8 report
Lattice a	2.8537 Å	298.15	αU alloy: U 1	unspecified	[8] Chatain 2003 cites David	Table 2, p. 3, row 6 report
Lattice a	10.759 Å	298.15	βU alloy: U 1	unspecified	[8] Chatain 2003 cites David	Table 2, p. 3, row 7 report
Lattice a	3.524 Å	298.15	γU alloy: U 1	unspecified	[8] Chatain 2003 cites David	Table 2, p. 3, row 8 report
Lattice a	10.759 Å	993.15	(βU) (βU): U 1	unspecified	[1] Sheldon 1987	Table 3, p. 3, row 7 report
Lattice a	3.524 Å	1078.15	(γU) (γU): U 1	unspecified	[1] Sheldon 1987	Table 3, p. 3, row 6 report
Lattice b	10.59 Å		βU alloy: U 1	model	[7] Moussa 2018 cites Massalski 1990	Table 1, p. 3, row 2 report
Lattice b	5.8695 Å	298.15	(αU) (αU): U 1	unspecified	[1] Sheldon 1987	Table 3, p. 3, row 8 report
Lattice b	5.8695 Å	298.15	αU alloy: U 1	unspecified	[8] Chatain 2003 cites David	Table 2, p. 3, row 6 report
Lattice c	5.634 Å		βU alloy: U 1	model	[7] Moussa 2018 cites Massalski 1990	Table 1, p. 3, row 2 report
Lattice c	4.9548 Å	298.15	(αU) (αU): U 1	unspecified	[1] Sheldon 1987	Table 3, p. 3, row 8 report
Lattice c	4.9548 Å	298.15	αU alloy: U 1	unspecified	[8] Chatain 2003 cites David	Table 2, p. 3, row 6 report
Lattice c	5.656 Å	298.15	βU alloy: U 1	unspecified	[8] Chatain 2003 cites David	Table 2, p. 3, row 7 report
Lattice c	5.656 Å	993.15	(βU) (βU): U 1	unspecified	[1] Sheldon 1987	Table 3, p. 3, row 7 report
Molar volume printed: V	12.65 cm^3 mol^-1		B.c.c. alloy: U 1	unspecified	[9] Ogawa 1993	Table 1, p. 2, row 2 report
Molar volume printed: V	12.65 cm^3 mol^-1		F.c.c. alloy: U 1	unspecified	[9] Ogawa 1993	Table 1, p. 2, row 3 report
Molar volume printed: V	13.78 cm^3 mol^-1		Liquid alloy: U 1	unspecified	[9] Ogawa 1993	Table 1, p. 2, row 1 report

Sources

Reporting papers the values were read from (a value cited from another work names that work in its row).

R. I. Sheldon, E. M. Foltyn, D. E. Peterson, The Sn-U (Tin-Uranium) system, Bulletin of Alloy Phase Diagrams 8, 347-352 (1987). doi:10.1007/bf02869271
A. Berche, N. Dupin, C. Guéneau, C. Rado, B. Sundman, J.C. Dumas, Calphad thermodynamic description of some binary systems involving U, Journal of Nuclear Materials 411, 131-143 (2011). doi:10.1016/j.jnucmat.2011.01.043
C. Guéneau, M. Baichi, D. Labroche, C. Chatillon, B. Sundman, Thermodynamic assessment of the uranium–oxygen system, Journal of Nuclear Materials 304, 161-175 (2002). doi:10.1016/s0022-3115(02)00878-4
O. Beneš, D. Manara, R.J.M. Konings, Thermodynamic assessment of the Th–U–Pu system, Journal of Nuclear Materials 449, 15-22 (2014). doi:10.1016/j.jnucmat.2014.02.001
Chuan Mo, Wenlin Mo, Baixue Bian, Peng Zhou, Yong Du, Tao Fa et al., Experimental investigation of the U-rich region and thermodynamic re-assessment of the U–Ti system, Journal of Nuclear Materials 557, 153317 (2021). doi:10.1016/j.jnucmat.2021.153317
A. Perron, P.E.A. Turchi, A. Landa, B. Oudot, B. Ravat, F. Delaunay, Thermodynamic assessments and inter-relationships between systems involving Al, Am, Ga, Pu, and U, Journal of Nuclear Materials 482, 187-200 (2016). doi:10.1016/j.jnucmat.2016.09.012
Chantal Moussa, Alexandre Berche, José Barbosa, Mathieu Pasturel, Bertrand Stepnik, Olivier Tougait, Experimental investigation of the phase equilibria and thermodynamic assessment in the U-Ga and U-Al-Ga systems, Journal of Nuclear Materials 499, 361-371 (2018). doi:10.1016/j.jnucmat.2017.11.037
S. Chatain, C. Guéneau, D. Labroche, O. Dugne, J. Rogez, Thermodynamic assessment of the Fe-U binary system, JPE 24, 122-131 (2003). doi:10.1361/105497103770330730
Toru Ogawa, Alloying behaviour among U, Np, Pu and Am predicted with the Brewer valence bond model, Journal of Alloys and Compounds 194, 1-7 (1993). doi:10.1016/0925-8388(93)90636-2

Please cite

R. Arróyave, J. Saal, D. Shin, ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735569
R. Arróyave, J. Saal, D. Shin, ORCHID data: umbrella record of the ORCHID datasets (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23736065

Also cite the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work); B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, https://doi.org/10.1016/j.calphad.2025.102833 (CC BY 4.0), and the original assessment named in each file; A. Jain et al., The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002, https://doi.org/10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501, https://doi.org/10.1007/s11837-013-0755-4 and S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010, https://doi.org/10.1038/npjcompumats.2015.10 (CC BY 4.0). 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.

@misc{orchid_literature_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735569},
  url       = {https://doi.org/10.5281/zenodo.23735569},
  note      = {Version 1, machine-extracted}
}

@misc{orchid_data_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID data: umbrella record of the ORCHID datasets}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23736065},
  url       = {https://doi.org/10.5281/zenodo.23736065},
  note      = {Version 1, machine-extracted}
}