AlAs: enthalpy of formation

11 accepted literature formation-enthalpy value(s) (experimental 8, model 2, unspecified 1).

Literature values

Enthalpy of formation of AlAs reported in the literature (11)
Value	Phase as printed	T (K)	Class	Method	System	Source	Location
-74.1 kJ/mol (basis unstated) ± 6.5	Al0.5As0.5(c)	298.15	experimental	solution calorimetry	Al–As	[1] Ansara 1984 cites ref. 40	Table V, p. 8, row 1 report
-74.1 unknown ± 6.5	Al0.5As0.5(c)	298.15	experimental	solution calorimetry	Al–As	[1] Ansara 1984 cites ref. 40	Table V, p. 8, row 1 report
-60.37 kJ/mol (basis unstated) ± 0.63	Al0.5As0.5(c)	298.15	experimental	Mass spectrometry	Al–As	[1] Ansara 1984 cites ref. 14	Table V, p. 8, row 3 report
-60.37 unknown ± 0.63	Al0.5As0.5(c)	298.15	experimental	Mass spectrometry	Al–As	[1] Ansara 1984 cites ref. 14	Table V, p. 8, row 3 report
-58.2 kJ/mol (basis unstated) ± 1.2	Al0.5As0.5(c)	298.15	experimental	Sn solution calorimetry	Al–As	[1] Ansara 1984 cites ref. 38	Table V, p. 8, row 2 report
-58.2 unknown ± 1.2	Al0.5As0.5(c)	298.15	experimental	Sn solution calorimetry	Al–As	[1] Ansara 1984 cites ref. 38	Table V, p. 8, row 2 report
-31 kJ/mol (basis unstated) ± 3.5	Al0.5As0.5(c)	298.15	experimental	Mass spectrometry and Knudsen effusion	Al–As	[1] Ansara 1984 cites ref. 41	Table V, p. 8, row 4 report
-31 unknown ± 3.5	Al0.5As0.5(c)	298.15	experimental	Mass spectrometry and Knudsen effusion	Al–As	[1] Ansara 1984 cites ref. 41	Table V, p. 8, row 4 report
-117.1 kJ/mol (basis unstated)	AlAs	298.15	model		Al–As	[2] Onderka 2002 cites Ansara 1994	Table AI, p. 18, row 47 report
-117.1 kJ/mol (basis unstated)	AlAs	298.15	model		Al–As	[2] Onderka 2002 cites Kaufman 1981	Table AI, p. 18, row 49 report
-134.6 kJ/mol (basis unstated)	AlAs	298.15	unspecified		Al–As	[2] Onderka 2002 cites Wagman 1968	Table AI, p. 18, row 48 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 AlAs
Value	Unit	Printed	Reading	Method (class, basis)	Effective
-74.1	kJ/mol (basis unstated)	6.5	0.05	3.2 (solution_reaction_calorimetry, calibrated)	6.5
-74.1	unknown	6.5	0.05	unit 'unknown' not convertible to kJ/mol-atom	6.5
-60.37	kJ/mol (basis unstated)	0.63	0.005	4.2 (kems_vapour, calibrated)	4.2
-60.37	unknown	0.63	0.005	unit 'unknown' not convertible to kJ/mol-atom	0.63
-58.2	kJ/mol (basis unstated)	1.2	0.05	3.2 (solution_reaction_calorimetry, calibrated)	3.2
-58.2	unknown	1.2	0.05	unit 'unknown' not convertible to kJ/mol-atom	1.2
-31	kJ/mol (basis unstated)	3.5	0.5	4.2 (kems_vapour, calibrated)	4.2
-31	unknown	3.5	0.5	unit 'unknown' not convertible to kJ/mol-atom	3.5
-117.1	kJ/mol (basis unstated)		0.05	7.8 (model_calculated, calibrated)	7.8
-117.1	kJ/mol (basis unstated)		0.05	7.8 (model_calculated, calibrated)	7.8
-134.6	kJ/mol (basis unstated)		0.05	7 (unknown, calibrated)	7

Sources

I. Ansara, D. Dutartre, Thermodynamic study of the Al-Ga-As-Ge system, Calphad 8, 323-342 (1984). doi:10.1016/0364-5916(84)90035-x
B. Onderka, J. Unland, R. Schmid-Fetzer, Thermodynamics and phase stability in the In–N system, J. Mater. Res. 17, 3065-3083 (2002). doi:10.1557/jmr.2002.0445

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}
}