Ag2Se: enthalpy of formation

24 accepted literature formation-enthalpy value(s) (experimental 14, model 2, DFT 8); experimental median -13.623 kJ/mol-atom (n = 14); Materials Project -21.663 kJ/mol-atom (mp-aaabgjqe); OQMD -7.938 kJ/mol-atom (oqmd-1374449).

Systems: Ag–Se

Literature values

Enthalpy of formation of Ag2Se reported in the literature (24)
Value	Phase as printed	T (K)	Class	Method	System	Source	Location
-14.3633 kJ/mol-atom	α-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Voronin 2011 doi	Table 1, p. 3, row 4 report
-14.2433 kJ/mol-atom	α-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Osadchii 2007 doi	Table 1, p. 3, row 1 report
-14.2333 kJ/mol-atom	β-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Nasar 1997 doi	Table 1, p. 3, row 15 report
-14.2333 kJ/mol-atom	α-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Nasar 1997 doi	Table 1, p. 3, row 2 report
-14.1367 kJ/mol-atom	α-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Voronin 2011 doi	Table 1, p. 3, row 3 report
-14.12 kJ/mol-atom	α-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Grnvold 2003 doi	Table 1, p. 3, row 7 report
-13.7067 kJ/mol-atom	α-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Feng 2013 doi	Table 1, p. 3, row 8 report
-13.54 kJ/mol-atom	α-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Oehsen 1981 doi	Table 1, p. 3, row 5 report
-13.3667 kJ/mol-atom	α-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Olin 2005	Table 1, p. 3, row 6 report
-11.6867 kJ/mol-atom	β-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Feng 2013 doi	Table 1, p. 3, row 13 report
-11.6833 kJ/mol-atom	β-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Grnvold 2003 doi	Table 1, p. 3, row 12 report
-11.68 kJ/mol-atom	β-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Voronin 2011 doi	Table 1, p. 3, row 11 report
-11.6733 kJ/mol-atom	β-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Osadchii 2007 doi	Table 1, p. 3, row 10 report
-11.6667 kJ/mol-atom	β-Ag2Se	298.15	experimental		Ag–Se	[1] Li 2018 cites Oehsen 1981 doi	Table 1, p. 3, row 14 report
-14.2433 kJ/mol-atom	α-Ag2Se	298.15	model		Ag–Se	[1] Li 2018	Table 1, p. 3, row 9 report
-11.67 kJ/mol-atom	β-Ag2Se	298.15	model		Ag–Se	[1] Li 2018	Table 1, p. 3, row 16 report
-9.936 kJ/mol-atom	α-Ag2Se		DFT	DFT	Ag–Se	[1] Li 2018	Table 4, p. 6, row 1 report
-9.936 kJ/mol-atom	α-Ag₂Se	0	DFT	DFT	Ag–Se	[1] Li 2018	Table 4, p. 6, row 1 report
-5.869 kJ/mol-atom	α-Ag2Se		DFT	DFT	Ag–Se	[1] Li 2018	Table 4, p. 6, row 2 report
-5.869 kJ/mol-atom	α-Ag₂Se	0	DFT	DFT	Ag–Se	[1] Li 2018	Table 4, p. 6, row 2 report
-4.127 kJ/mol-atom	β-Ag2Se		DFT	DFT	Ag–Se	[1] Li 2018	Table 4, p. 6, row 7 report
-4.127 kJ/mol-atom	β-Ag₂Se	0	DFT	DFT	Ag–Se	[1] Li 2018	Table 4, p. 6, row 7 report
-3.196 kJ/mol-atom	β-Ag2Se		DFT	DFT	Ag–Se	[1] Li 2018	Table 4, p. 6, row 8 report
-3.196 kJ/mol-atom	β-Ag₂Se	0	DFT	DFT	Ag–Se	[1] Li 2018	Table 4, p. 6, row 8 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 Ag2Se
Value	Unit	Reading	Method (class, basis)	Effective
-14.3633	kJ/mol-atom	0.001667	3.5 (unknown, calibrated)	3.5
-14.2433	kJ/mol-atom	0.001667	3.5 (unknown, calibrated)	3.5
-14.2333	kJ/mol-atom	0.01667	3.5 (unknown, calibrated)	3.5
-14.2333	kJ/mol-atom	0.01667	3.5 (unknown, calibrated)	3.5
-14.1367	kJ/mol-atom	0.001667	3.5 (unknown, calibrated)	3.5
-14.12	kJ/mol-atom	0.001667	3.5 (unknown, calibrated)	3.5
-13.7067	kJ/mol-atom	0.001667	3.5 (unknown, calibrated)	3.5
-13.54	kJ/mol-atom	0.001667	3.5 (unknown, calibrated)	3.5
-13.3667	kJ/mol-atom	0.01667	3.5 (unknown, calibrated)	3.5
-11.6867	kJ/mol-atom	0.001667	3.5 (unknown, calibrated)	3.5
-11.6833	kJ/mol-atom	0.001667	3.5 (unknown, calibrated)	3.5
-11.68	kJ/mol-atom	0.001667	3.5 (unknown, calibrated)	3.5
-11.6733	kJ/mol-atom	0.001667	3.5 (unknown, calibrated)	3.5
-11.6667	kJ/mol-atom	0.01667	3.5 (unknown, calibrated)	3.5
-14.2433	kJ/mol-atom	0.001667	3.9 (model_calculated, calibrated)	3.9
-11.67	kJ/mol-atom	0.001667	3.9 (model_calculated, calibrated)	3.9
-9.936	kJ/mol-atom	5.000e-4	9.966 (dft, calibrated)	9.966
-9.936	kJ/mol-atom	5.000e-4	9.966 (dft, calibrated)	9.966
-5.869	kJ/mol-atom	5.000e-4	9.966 (dft, calibrated)	9.966
-5.869	kJ/mol-atom	5.000e-4	9.966 (dft, calibrated)	9.966
-4.127	kJ/mol-atom	5.000e-4	9.966 (dft, calibrated)	9.966
-4.127	kJ/mol-atom	5.000e-4	9.966 (dft, calibrated)	9.966
-3.196	kJ/mol-atom	5.000e-4	9.966 (dft, calibrated)	9.966
-3.196	kJ/mol-atom	5.000e-4	9.966 (dft, calibrated)	9.966

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 Ag2Se
Source	Entry	kJ/mol-atom	eV/atom	Space group	E above hull (kJ/mol-atom)	E above hull (eV/atom)	Theoretical
Materials Project	mp-aaabgjqe	-21.663	-0.224522	P2_12_12_1	0	0	no
OQMD	oqmd-1374449	-7.938	-0.082276	Cmcm	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

Zhi Li, Shun-Li Shang, Jianyun Shen, Po-Hsien Liao, Zi-Kui Liu, Timothy J. Anderson, Thermodynamic Assessment of the Ag-Se System Aided by First-Principles Calculations, J. Phase Equilib. Diffus. 39, 870-881 (2018). doi:10.1007/s11669-018-0683-7

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}
}