UC1.9: enthalpy of formation

7 accepted literature formation-enthalpy value(s) (experimental 6, model 1); experimental median -31.38 kJ/mol-atom (n = 6).

Systems: C–U

Literature values

Enthalpy of formation of UC1.9 reported in the literature (7)
Value	Phase as printed	T (K)	Class	System	Source	Location
-33.89 kJ/mol-atom	UC1.90	298.15	experimental	C–U	[1] Chevalier 2001 cites Norman 1964 doi	Table 21, p. 17, row 17 report
-33.325 kJ/mol-atom ± 1.908	UC1.90	298.15	experimental	C–U	[1] Chevalier 2001 cites Tetenbaum 1971 doi	Table 21, p. 17, row 23 report
-31.798 kJ/mol-atom	UC1.90	298.15	experimental	C–U	[1] Chevalier 2001 cites Eich 1962	Table 21, p. 17, row 14 report
-30.962 kJ/mol-atom	UC1.90	298.15	experimental	C–U	[1] Chevalier 2001 cites Piazza 1962 doi	Table 21, p. 17, row 12 report
-30.298 kJ/mol-atom ± 0.289	UC1.90	298.15	experimental	C–U	[1] Chevalier 2001 cites MacLeod 1969	Table 21, p. 17, row 24 report
-30.125 kJ/mol-atom	UC1.90	298.15	experimental	C–U	[1] Chevalier 2001 cites Behl 1966 doi	Table 21, p. 17, row 19 report
-30.533 kJ/mol-atom	UC1.90	298.15	model	C–U	[1] Chevalier 2001	Table 21, p. 17, row 26 report

Uncertainty budget

Components kept separate, in the value's unit (literature SCHEMA.md, UNCERTAINTY_CALIBRATION.md): effective = max(sqrt(max(printed, reading, method)^2 + composition^2 + conversion^2), scatter). The method floor is the robust between-study scatter of the method class in ORCHID (calibrated) or a documented prior; printed values and printed uncertainties are unchanged.

Uncertainty budget of the literature values of UC1.9
Value	Unit	Printed	Reading	Method (class, basis)	Effective
-33.89	kJ/mol-atom		5.000e-4	3.5 (unknown, calibrated)	3.5
-33.325	kJ/mol-atom	1.908	5.000e-4	3.5 (unknown, calibrated)	3.5
-31.798	kJ/mol-atom		5.000e-4	3.5 (unknown, calibrated)	3.5
-30.962	kJ/mol-atom		5.000e-4	3.5 (unknown, calibrated)	3.5
-30.298	kJ/mol-atom	0.289	5.000e-4	3.5 (unknown, calibrated)	3.5
-30.125	kJ/mol-atom		5.000e-4	3.5 (unknown, calibrated)	3.5
-30.533	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9

Sources

P.Y Chevalier, E Fischer, Thermodynamic modelling of the C–U and B–U binary systems, Journal of Nuclear Materials 288, 100-129 (2001). doi:10.1016/s0022-3115(00)00713-3

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-Parity: DFT-vs-experiment formation-enthalpy benchmark (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735943
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); 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); G. Kim, S. V. Meschel, P. Nash, W. Chen, Experimental formation enthalpies for intermetallic phases and other inorganic compounds, Scientific Data 4 (2017) 170162, https://doi.org/10.1038/sdata.2017.162; 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. 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_dft_benchmark_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Parity: DFT-vs-experiment formation-enthalpy benchmark}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735943},
  url       = {https://doi.org/10.5281/zenodo.23735943},
  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}
}