Ca2SiO4: enthalpy of formation

8 accepted literature formation-enthalpy value(s) (model 8).

Literature values

Enthalpy of formation of Ca2SiO4 reported in the literature (8)
Value	Phase as printed	T (K)	Class	System	Source	Location
-2548 kJ/mol (basis unstated)	α-Ca2SiO4	298.15	model	Ca–O–Si	[1] Abdul 2023 cites Haas 1981 doi	Table 7, p. 8, row 12 report
-2316 kJ/mol (basis unstated)	γ-Ca2SiO4	298.15	model	Ca–O–Si	[1] Abdul 2023	Table 7, p. 8, row 17 report
-2316 kJ/mol (basis unstated)	γ-Ca2SiO4	298.15	model	Ca–O–Si	[1] Abdul 2023 cites Haas 1981 doi	Table 7, p. 8, row 18 report
-2307 kJ/mol (basis unstated)	β-Ca2SiO4	298.15	model	Ca–O–Si	[1] Abdul 2023	Table 7, p. 8, row 15 report
-2306 kJ/mol (basis unstated)	β-Ca2SiO4	298.15	model	Ca–O–Si	[1] Abdul 2023 cites Haas 1981 doi	Table 7, p. 8, row 16 report
-2304 kJ/mol (basis unstated)	α′-Ca2SiO4	298.15	model	Ca–O–Si	[1] Abdul 2023	Table 7, p. 8, row 13 report
-2293 kJ/mol (basis unstated)	α-Ca2SiO4	298.15	model	Ca–O–Si	[1] Abdul 2023	Table 7, p. 8, row 11 report
-2198 kJ/mol (basis unstated)	α′-Ca2SiO4	298.15	model	Ca–O–Si	[1] Abdul 2023 cites Haas 1981 doi	Table 7, p. 8, row 14 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 Ca2SiO4
Value	Unit	Reading	Method (class, basis)	Effective
-2548	kJ/mol (basis unstated)	0.05	27.3 (model_calculated, calibrated)	27.3
-2316	kJ/mol (basis unstated)	0.05	27.3 (model_calculated, calibrated)	27.3
-2316	kJ/mol (basis unstated)	0.05	27.3 (model_calculated, calibrated)	27.3
-2307	kJ/mol (basis unstated)	0.05	27.3 (model_calculated, calibrated)	27.3
-2306	kJ/mol (basis unstated)	0.05	27.3 (model_calculated, calibrated)	27.3
-2304	kJ/mol (basis unstated)	0.05	27.3 (model_calculated, calibrated)	27.3
-2293	kJ/mol (basis unstated)	0.05	27.3 (model_calculated, calibrated)	27.3
-2198	kJ/mol (basis unstated)	0.05	27.3 (model_calculated, calibrated)	27.3

Sources

Wahab Abdul, Chancel Mawalala, Alexander Pisch, Marcus Nigel Bannerman, CaO-SiO2 assessment using 3rd generation CALPHAD models, Cement and Concrete Research 173, 107309 (2023). doi:10.1016/j.cemconres.2023.107309

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}
}