Fe2Ho: enthalpy of formation

10 accepted literature formation-enthalpy value(s) (experimental 4, model 5, DFT 1).

Literature values

Enthalpy of formation of Fe2Ho reported in the literature (10)
Value	Phase as printed	T (K)	Class	Method	System	Source	Location
-6.2 kJ/mol (basis unstated)	Fe2Ho	300	experimental	Adiabatic Calo.	Fe–Ho	[1] Kardellass 2014 cites Germano 1981 doi	Table 3, p. 3, row 19 report
-5.9 kJ/mol (basis unstated)	Fe2Ho	290	experimental	Adiabatic Calo.	Fe–Ho	[1] Kardellass 2014 cites Germano 1981 doi	Table 3, p. 3, row 18 report
-4.3 kJ/mol (basis unstated)	Fe2Ho	298.15	experimental	EMF	Fe–Ho	[1] Kardellass 2014 cites Latini 2013 doi	Table 3, p. 3, row 14 report
-2.6 kJ/mol (basis unstated) ± 3.3	Fe2Ho	1373	experimental	DSC	Fe–Ho	[1] Kardellass 2014 cites Meschel 2013 doi	Table 3, p. 3, row 16 report
-6.2 kJ/mol (basis unstated)	Fe2Ho	300	model	Calculation	Fe–Ho	[1] Kardellass 2014 cites Germano 1981 doi	Table 3, p. 3, row 13 report
-3 kJ/mol (basis unstated)	Fe2Ho	298.15	model	Prediction	Fe–Ho	[1] Kardellass 2014 cites Kardellass 2013	Table 3, p. 3, row 11 report
-2.97 kJ/mol (basis unstated)	Fe2Ho	298.15	model	Prediction	Fe–Ho	[1] Kardellass 2014 cites Pauling	Table 3, p. 3, row 20 report
-2.9 kJ/mol (basis unstated)	Fe2Ho	298.15	model	Prediction	Fe–Ho	[1] Kardellass 2014 cites Niessen 1983 doi	Table 3, p. 3, row 12 report
-2.65 kJ/mol (basis unstated)	Fe2Ho	298.15	model	Optimization	Fe–Ho	[1] Kardellass 2014	Table 3, p. 3, row 17 report
-9.5 kJ/mol (basis unstated)	Fe2Ho	298.15	DFT	Ab initio	Fe–Ho	[1] Kardellass 2014 cites Pauling	Table 3, p. 3, row 15 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 Fe2Ho
Value	Unit	Printed	Reading	Method (class, basis)	Effective
-6.2	kJ/mol (basis unstated)		0.05	10.5 (heat_content_calorimetry, calibrated)	10.5
-5.9	kJ/mol (basis unstated)		0.05	10.5 (heat_content_calorimetry, calibrated)	10.5
-4.3	kJ/mol (basis unstated)		0.05	13.8 (emf, cleaned_below_threshold)	13.8
-2.6	kJ/mol (basis unstated)	3.3	0.05	6 (dsc_dta, prior)	6
-6.2	kJ/mol (basis unstated)		0.05	11.7 (model_calculated, calibrated)	11.7
-3	kJ/mol (basis unstated)		0.05	11.7 (model_calculated, calibrated)	11.7
-2.97	kJ/mol (basis unstated)		0.005	11.7 (model_calculated, calibrated)	11.7
-2.9	kJ/mol (basis unstated)		0.05	11.7 (model_calculated, calibrated)	11.7
-2.65	kJ/mol (basis unstated)		0.005	11.7 (model_calculated, calibrated)	11.7
-9.5	kJ/mol (basis unstated)		0.05	11.79 (dft, calibrated)	11.79

Sources

S. Kardellass, C. Servant, N. Selhaoui, A. Iddaoudi, M. Ait Amar, L. Bouirden, A thermodynamic assessment of the Iron+Holmium phase diagram, The Journal of Chemical Thermodynamics 74, 78-84 (2014). doi:10.1016/j.jct.2013.11.037

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}
}