CuHf2: enthalpy of formation

10 accepted literature formation-enthalpy value(s) (experimental 2, model 4, DFT 3, unspecified 1); experimental median -15.23 kJ/mol-atom (n = 1); Materials Project -15.432 kJ/mol-atom (mp-aaaabtgf); OQMD -15.582 kJ/mol-atom (oqmd-1895392).

Systems: Cu–Hf

Literature values

Enthalpy of formation of CuHf2 reported in the literature (10)
Value	Phase as printed	T (K)	Class	Method	System	Source	Location
-15.23 kJ/mol-atom	CuHf2	298.15	experimental		Cu–Hf	[1] Zhong 2013 cites Kleppa 1982 doi	Table 2, p. 7, row 1 report
-15.23 kJ/mol (basis unstated) ± 0.5	CuHf2	298.15	experimental		Cu–Hf	[2] Turchanin 2008 cites ref. 20	Table 2, p. 6, row 12 report
-56.12 kJ/mol-atom	CuHf2		model		Cu–Hf	[1] Zhong 2013 cites Subramanian 1988	Table 2, p. 7, row 2 report
-20.75 kJ/mol-atom	CuHf2		model		Cu–Hf	[1] Zhong 2013 cites Turchanin 2008 doi	Table 2, p. 7, row 4 report
-19.174 kJ/mol (basis unstated)	CuHf2	298.15	model		Cu–Hf	[2] Turchanin 2008	Table 2, p. 6, row 14 report
-19.17 kJ/mol-atom	CuHf2		model		Cu–Hf	[1] Zhong 2013 cites Liang 2006 doi	Table 2, p. 7, row 3 report
-16.36 kJ/mol-atom	CuHf2		DFT	USPP-GGA F-P	Cu–Hf	[1] Zhong 2013 cites Ghosh 2007 doi	Table 2, p. 7, row 5 report
-16.22 kJ/mol-atom	CuHf2	0	DFT	USPP-GGA	Cu–Hf	[1] Zhong 2013	Table 2, p. 7, row 6 report
-15.5 kJ/mol-atom	CuHf2	0	DFT	PBE	Cu–Hf	[1] Zhong 2013	Table 2, p. 7, row 7 report
-56.12 kJ/mol (basis unstated)	CuHf2	298.15	unspecified		Cu–Hf	[2] Turchanin 2008 cites ref. 13	Table 2, p. 6, row 13 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 CuHf2
Value	Unit	Printed	Reading	Method (class, basis)	Effective
-15.23	kJ/mol-atom		0.005	3.5 (unknown, calibrated)	3.5
-15.23	kJ/mol (basis unstated)	0.5	5.000e-4	10.5 (unknown, calibrated)	10.5
-56.12	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-20.75	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-19.174	kJ/mol (basis unstated)		5.000e-4	11.7 (model_calculated, calibrated)	11.7
-19.17	kJ/mol-atom		0.005	3.9 (model_calculated, calibrated)	3.9
-16.36	kJ/mol-atom		0.005	8.395 (dft, calibrated)	8.395
-16.22	kJ/mol-atom		0.005	8.395 (dft, calibrated)	8.395
-15.5	kJ/mol-atom		0.05	8.395 (dft, calibrated)	8.395
-56.12	kJ/mol (basis unstated)		5.000e-4	10.5 (unknown, calibrated)	10.5

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 CuHf2
Source	Entry	kJ/mol-atom	eV/atom	Space group	E above hull (kJ/mol-atom)	E above hull (eV/atom)	Theoretical
Materials Project	mp-aaaabtgf	-15.432	-0.159939	I4/mmm	0	0	no
OQMD	oqmd-1895392	-15.582	-0.161494	P4mm	0	0	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

Yu Zhong, Arkapol Saengdeejing, Laszlo Kecskes, Bradley Klotz, Zi-Kui Liu, Experimental and computational studies of the Cu–Hf binary system, Acta Materialia 61, 660-669 (2013). doi:10.1016/j.actamat.2012.10.014
M. A. Turchanin, P. G. Agraval, Thermodynamic assessment of the copper-hafnium system, Powder Metall Met Ceram 47, 223-233 (2008). doi:10.1007/s11106-008-9008-4

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}
}