CeRu2: enthalpy of formation

14 accepted literature formation-enthalpy value(s) (experimental 1, model 7, DFT 6); experimental median -27.9 kJ/mol-atom (n = 1); Materials Project -27.343 kJ/mol-atom (mp-aaaaaaxj); OQMD -5.092 kJ/mol-atom (oqmd-1800977).

Systems: Ce–Ru

Literature values

Enthalpy of formation of CeRu2 reported in the literature (14)
Value	Phase as printed	T (K)	Class	Method	System	Source	Location
-27.9 kJ/mol-atom ± 1.5	CeRu2	298.15	experimental	Direct Synthesis Calorimetry	Ce–Ru	[1] Kardellass 2023 cites Selhaoui 1993 doi	Table 3, p. 9, row 57 report
-41.9778 kJ/mol-atom	CeRu2		model	Miedema’s model	Ce–Ru	[1] Kardellass 2023 cites De 2014	Table 3, p. 9, row 61 report
-32.2203 kJ/mol-atom	CeRu2		model	Modified Miedema’s model	Ce–Ru	[1] Kardellass 2023 cites Zhang 2007 doi	Table 3, p. 9, row 68 report
-29.721 kJ/mol-atom	CeRu2		model	Calculation II	Ce–Ru	[1] Kardellass 2023 cites Selhaoui 1998 doi	Table 3, p. 9, row 59 report
-29.72 kJ/mol-atom	CeRu2		model	Calculation I	Ce–Ru	[1] Kardellass 2023 cites Selhaoui 1998 doi	Table 3, p. 9, row 58 report
-22.5988 kJ/mol-atom	CeRu2		model	Optimization CM	Ce–Ru	[1] Kardellass 2023	Table 3, p. 9, row 56 report
-18.9068 kJ/mol-atom	CeRu2		model	Optimization LM	Ce–Ru	[1] Kardellass 2023	Table 3, p. 9, row 54 report
-14.6208 kJ/mol-atom	CeRu2		model	Optimization EM	Ce–Ru	[1] Kardellass 2023	Table 3, p. 9, row 55 report
-30.848 kJ/mol-atom	CeRu2		DFT	Ab-initio	Ce–Ru	[1] Kardellass 2023 cites Kirklin 2015 doi	Table 3, p. 9, row 65 report
-28.0524 kJ/mol-atom	CeRu2		DFT	Ab-initio	Ce–Ru	[1] Kardellass 2023 cites Choudhary 2020 doi	Table 3, p. 9, row 66 report
-27.281 kJ/mol-atom	CeRu2		DFT	Ab-initio	Ce–Ru	[1] Kardellass 2023 cites Ceder 2010	Table 3, p. 9, row 64 report
-27.2586 kJ/mol-atom	CeRu2	0	DFT	Ab-initio	Ce–Ru	[1] Kardellass 2023	Table 3, p. 9, row 67 report
-27.1978 kJ/mol-atom	CeRu2	0	DFT	Ab-initio (Magnetic)	Ce–Ru	[1] Kardellass 2023	Table 3, p. 9, row 62 report
-27.1978 kJ/mol-atom	CeRu2	0	DFT	Ab-initio (No-magnetic)	Ce–Ru	[1] Kardellass 2023	Table 3, p. 9, row 63 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 CeRu2
Value	Unit	Printed	Reading	Method (class, basis)	Effective
-27.9	kJ/mol-atom	1.5	0.05	3.2 (solution_reaction_calorimetry, calibrated)	3.2
-41.9778	kJ/mol-atom		5.000e-6	3.9 (model_calculated, calibrated)	3.9
-32.2203	kJ/mol-atom		5.000e-6	3.9 (model_calculated, calibrated)	3.9
-29.721	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-29.72	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-22.5988	kJ/mol-atom		5.000e-6	3.9 (model_calculated, calibrated)	3.9
-18.9068	kJ/mol-atom		5.000e-6	3.9 (model_calculated, calibrated)	3.9
-14.6208	kJ/mol-atom		5.000e-5	3.9 (model_calculated, calibrated)	3.9
-30.848	kJ/mol-atom		5.000e-4	8.395 (dft, calibrated)	8.395
-28.0524	kJ/mol-atom		5.000e-5	8.395 (dft, calibrated)	8.395
-27.281	kJ/mol-atom		5.000e-4	8.395 (dft, calibrated)	8.395
-27.2586	kJ/mol-atom		5.000e-6	8.395 (dft, calibrated)	8.395
-27.1978	kJ/mol-atom		5.000e-6	8.395 (dft, calibrated)	8.395
-27.1978	kJ/mol-atom		5.000e-6	8.395 (dft, calibrated)	8.395

DFT formation energies

Lowest-energy entries at this composition. Materials Project and OQMD use different energy references and are never averaged. 1 eV/atom = 96.485 kJ/mol-atom.

DFT formation energy of CeRu2
Source	Entry	kJ/mol-atom	eV/atom	Space group	E above hull (kJ/mol-atom)	E above hull (eV/atom)	Theoretical
Materials Project	mp-aaaaaaxj	-27.343	-0.283391	Fd-3m	0	0	no
OQMD	oqmd-1800977	-5.092	-0.052774	P63/mmc	0.8437	0.0087	yes

DFT sources: A. Jain et al., Commentary: The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002. doi:10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501-1509; S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010. doi:10.1007/s11837-013-0755-4 (CC BY 4.0);

Sources

S. Kardellass, C. Corvalan-Moya, V. P. Vassiliev, Thermodynamic Modeling of the (Ce and Sm)-Ru Binary Systems Based on Linear, Exponential, and Combined Models Aided by Ab-Initio Calculations, J. Phase Equilib. Diffus. 44, 300-323 (2023). doi:10.1007/s11669-023-01043-1

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}
}