CaPb3: enthalpy of formation

9 accepted literature formation-enthalpy value(s) (experimental 5, model 4); experimental median -34 kJ/mol-atom (n = 5); Materials Project -28.013 kJ/mol-atom (mp-aaaabekj); OQMD -32.338 kJ/mol-atom (oqmd-18782).

Systems: Ca–Pb

Literature values

Enthalpy of formation of CaPb3 reported in the literature (9)
Value	Phase as printed	T (K)	Class	Method	System	Source	Location
-35 kJ/mol-atom ± 0.3	CaPb3	900	experimental	dissolution calorimetry	Ca–Pb	[1] Cartigny 2004 cites Bouirden 1984	Table 2, p. 3, row 1 report
-35 kJ/mol-atom ± 0.3	CaPb3	900	experimental	Dissolution calorimetry	Ca–Pb	[2] Idbenali 2008 cites Bouirden 1984	Table 5, p. 8, row 16 report
-34 kJ/mol-atom ± 0.5	CaPb3	300	experimental	Solution calorimetry	Ca–Pb	[2] Idbenali 2008 cites Notin 1989 doi	Table 5, p. 8, row 19 report
-33.8 kJ/mol-atom ± 1.4	CaPb3	800	experimental	E.m.f.	Ca–Pb	[2] Idbenali 2008 cites Nouri 1985 doi	Table 5, p. 8, row 15 report
-33.2 kJ/mol-atom ± 2	CaPb3	300	experimental	Solution calorimetry	Ca–Pb	[2] Idbenali 2008 cites Sommer 2006 doi	Table 5, p. 8, row 18 report
-36.251 kJ/mol-atom	CaPb3	900	model		Ca–Pb	[1] Cartigny 2004	Table 2, p. 3, row 2 report
-36.251 kJ/mol-atom	CaPb3	900	model	Optimization	Ca–Pb	[2] Idbenali 2008 cites Cartigny 2004 doi	Table 5, p. 8, row 17 report
-33.966 kJ/mol-atom	CaPb3	300	model	Optimization	Ca–Pb	[2] Idbenali 2008	Table 5, p. 8, row 21 report
-32.358 kJ/mol-atom	CaPb3	300	model	Optimization from [12]	Ca–Pb	[2] Idbenali 2008	Table 5, p. 8, row 20 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 CaPb3
Value	Unit	Printed	Reading	Method (class, basis)	Effective
-35	kJ/mol-atom	0.3	0.05	3.2 (solution_reaction_calorimetry, calibrated)	3.2
-35	kJ/mol-atom	0.3	0.5	3.2 (solution_reaction_calorimetry, calibrated)	3.2
-34	kJ/mol-atom	0.5	0.5	3.2 (solution_reaction_calorimetry, calibrated)	3.2
-33.8	kJ/mol-atom	1.4	0.05	4.6 (emf, cleaned_below_threshold)	4.6
-33.2	kJ/mol-atom	2	0.05	3.2 (solution_reaction_calorimetry, calibrated)	3.2
-36.251	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-36.251	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-33.966	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9
-32.358	kJ/mol-atom		5.000e-4	3.9 (model_calculated, calibrated)	3.9

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 CaPb3
Source	Entry	kJ/mol-atom	eV/atom	Space group	E above hull (kJ/mol-atom)	E above hull (eV/atom)	Theoretical
Materials Project	mp-aaaabekj	-28.013	-0.290333	Pm-3m	0	0	no
OQMD	oqmd-18782	-32.338	-0.335163	Pm-3m	-0	-0	no

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

Y. Cartigny, J.M. Fiorani, A. Maı̂tre, M. Vilasi, Thermodynamic assessment of the Ca–Pb system, Thermochimica Acta 414, 197-202 (2004). doi:10.1016/j.tca.2004.01.001
M. Idbenali, C. Servant, N. Selhaoui, L. Bouirden, A thermodynamic reassessment of the Ca–Pb system, Calphad 32, 64-73 (2008). doi:10.1016/j.calphad.2007.10.004

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}
}