MgNi2: enthalpy of formation

13 accepted literature formation-enthalpy value(s) (experimental 10, model 3); experimental median -21.073 kJ/mol-atom (n = 5); Materials Project -21.279 kJ/mol-atom (mp-aaaaadyx); OQMD -22.517 kJ/mol-atom (oqmd-17634).

Systems: Mg–Ni

Literature values

Enthalpy of formation of MgNi2 reported in the literature (13)
Value	Phase as printed	T (K)	Class	Method	System	Source	Location
-77.87 kJ/mol (basis unstated)	MgNi2	298.15	experimental		Mg–Ni	[1] Jacobs 1998 cites ref. 9	Table 4, p. 7, row 2 report
-59.91 kJ/mol (basis unstated)	MgNi2	298.15	experimental		Mg–Ni	[1] Jacobs 1998 cites ref. 12	Table 4, p. 7, row 6 report
-55.68 kJ/mol (basis unstated) ± 6.28	MgNi2	298.15	experimental		Mg–Ni	[1] Jacobs 1998 cites ref. 10	Table 4, p. 7, row 3 report
-55.27 kJ/mol (basis unstated) ± 2.1	MgNi2	298.15	experimental		Mg–Ni	[1] Jacobs 1998 cites ref. 11	Table 4, p. 7, row 5 report
-53.22 kJ/mol (basis unstated) ± 10	MgNi2	298.15	experimental		Mg–Ni	[1] Jacobs 1998 cites ref. 16	Table 4, p. 7, row 7 report
-25.92 kJ/mol-atom	MgNi2	298.15	experimental	Vap. press.	Mg–Ni	[2] Islam 2005 cites Schmahl 1958	Table 4, p. 7, row 4 report
-21.47 kJ/mol-atom	MgNi2	298.15	experimental	emf	Mg–Ni	[2] Islam 2005 cites Lukashenko 1966	Table 4, p. 7, row 3 report
-21.073 kJ/mol-atom	MgNi2	298.15	experimental	Soln. calo.	Mg–Ni	[2] Islam 2005 cites Feufel 1995 doi	Table 4, p. 7, row 7 report
-20.62 kJ/mol-atom	MgNi2	298.15	experimental	Vap. press.	Mg–Ni	[2] Islam 2005 cites Smith 1960 doi	Table 4, p. 7, row 6 report
-19.23 kJ/mol-atom	MgNi2	298.15	experimental	Soln. calo.	Mg–Ni	[2] Islam 2005 cites King 1964 doi	Table 4, p. 7, row 5 report
-55.65 kJ/mol (basis unstated) ± 4.61	MgNi2		model		Mg–Ni	[1] Jacobs 1998	Table 4, p. 7, row 4 report
-48.086 kJ/mol (basis unstated)	MgNi2		model		Mg–Ni	[1] Jacobs 1998	Table 4, p. 7, row 1 report
-21.55 kJ/mol-atom	MgNi2		model	Cal.	Mg–Ni	[2] Islam 2005	Table 4, p. 7, row 2 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 MgNi2
Value	Unit	Printed	Reading	Method (class, basis)	Effective
-77.87	kJ/mol (basis unstated)		0.005	10.5 (unknown, calibrated)	10.5
-59.91	kJ/mol (basis unstated)		0.005	10.5 (unknown, calibrated)	10.5
-55.68	kJ/mol (basis unstated)	6.28	0.005	10.5 (unknown, calibrated)	10.5
-55.27	kJ/mol (basis unstated)	2.1	0.005	10.5 (unknown, calibrated)	10.5
-53.22	kJ/mol (basis unstated)	10	0.005	10.5 (unknown, calibrated)	10.5
-25.92	kJ/mol-atom		0.005	4.2 (kems_vapour, calibrated)	4.2
-21.47	kJ/mol-atom		0.005	4.6 (emf, cleaned_below_threshold)	4.6
-21.073	kJ/mol-atom		5.000e-4	3.2 (solution_reaction_calorimetry, calibrated)	3.2
-20.62	kJ/mol-atom		0.005	4.2 (kems_vapour, calibrated)	4.2
-19.23	kJ/mol-atom		0.005	3.2 (solution_reaction_calorimetry, calibrated)	3.2
-55.65	kJ/mol (basis unstated)	4.61	0.005	11.7 (model_calculated, calibrated)	11.7
-48.086	kJ/mol (basis unstated)		5.000e-4	11.7 (model_calculated, calibrated)	11.7
-21.55	kJ/mol-atom		0.005	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 MgNi2
Source	Entry	kJ/mol-atom	eV/atom	Space group	E above hull (kJ/mol-atom)	E above hull (eV/atom)	Theoretical
Materials Project	mp-aaaaadyx	-21.279	-0.220546	P6_3/mmc	0	0	no
OQMD	oqmd-17634	-22.517	-0.233375	P63/mmc	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

M.H.G. Jacobs, P.J. Spencer, A critical thermodynamic evaluation of the system MG-NI, Calphad 22, 513-525 (1998). doi:10.1016/s0364-5916(99)00008-5
F. Islam, M. Medraj, The phase equilibria in the Mg–Ni–Ca system, Calphad 29, 289-302 (2005). doi:10.1016/j.calphad.2005.08.006

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}
}