O–Si system

36 accepted literature values from 3 paper(s) (model 2, DFT 3, unspecified 31); 0 calculated phase diagram(s). 9 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV.

Data: JSON · CSV · interactive explorer · phases (17) · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
model	2
DFT	3
unspecified	31

Accepted values by property group
Property group	Values
invariant reaction	3
crystal structure	31
other property	2

Convex hulls: Materials Project DFT hull · OQMD DFT hull · CALPHAD hull SiO-92Hal

Invariant reactions (literature)

Invariant reactions reported in the literature for the O–Si system (3)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location
2130	Gas -> L1 + L2	Gas: O 0.5; L1: O 4.100e-4; L2: O 0.66662	unspecified	[1] Hallstedt 1992	Table 3, p. 9, row 3 report
1994	monotectic: L2 -> L1 + Cristobalite	L2: O 0.66664; L1: O 2.600e-4; Cristobalite: O 0.66667	unspecified	[1] Hallstedt 1992	Table 3, p. 9, row 2 report
1687	eutectic: L1 -> (Si) + Tridymite	L1: O 6.300e-5; (Si): O 4.500e-5; Tridymite: O 0.66667	unspecified	[1] Hallstedt 1992	Table 3, p. 9, row 1 report

Other properties

Crystal structure (31)

Crystal structure, O–Si system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Lattice a	5.007 Å	0	Quartz (SiO2) alloy: O 0.666667, Si 0.333333	DFT	[2] Shin 2006	Table 1, p. 3, row 7 report
Lattice a	2.561 Å	298.15	SiO2(Fe2N-type) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 14 report
Lattice a	4.9877 Å	298.15	SiO2(low cristobalite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 8 report
Lattice a	4.957 Å	298.15	SiO2(low cristobalite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 7 report
Lattice a	9.94 Å	386 (<)	SiO2(tridymite M-I) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 4 report
Lattice a	5.046 Å	470.5	SiO2(tridymite S-IV) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 1 report
Lattice a	5.052 Å	470.5	SiO2(tridymite S-IV) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 1 report
Lattice a	7.464 Å	765.5	SiO2 I (keatite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 9 report
Lattice a	7.098 Å	838	SiO2 II (coesite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 10 report
Lattice a	4.176 Å	885.5	SiO2 III (stishovite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 12 report
Lattice a	7.137 Å	1273 (<)	SiO2 IIb (coesite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 11 report
Lattice a	4.72 Å	1368	SiO2 (silica W) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 13 report
Lattice b	5.007 Å	0	Quartz (SiO2) alloy: O 0.666667, Si 0.333333	DFT	[2] Shin 2006	Table 1, p. 3, row 7 report
Lattice b	17.21 Å	386 (<)	SiO2(tridymite M-I) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 4 report
Lattice b	12.334 Å	838	SiO2 II (coesite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 10 report
Lattice b	12.37 Å	1273 (<)	SiO2 IIb (coesite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 11 report
Lattice b	5.16 Å	1368	SiO2 (silica W) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 13 report
Lattice c	5.496 Å	0	Quartz (SiO2) alloy: O 0.666667, Si 0.333333	DFT	[2] Shin 2006	Table 1, p. 3, row 7 report
Lattice c	4.112 Å	298.15	SiO2(Fe2N-type) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 14 report
Lattice c	6.9679 Å	298.15	SiO2(low cristobalite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 8 report
Lattice c	6.8903 Å	298.15	SiO2(low cristobalite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 7 report
Lattice c	10.92 Å	386 (<)	SiO2(tridymite M-I) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 4 report
Lattice c	8.27 Å	470.5	SiO2(tridymite S-IV) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 1 report
Lattice c	8.236 Å	470.5	SiO2(tridymite S-IV) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 1 report
Lattice c	8.62 Å	765.5	SiO2 I (keatite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 9 report
Lattice c	7.148 Å	838	SiO2 II (coesite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 10 report
Lattice c	2.666 Å	885.5	SiO2 III (stishovite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 12 report
Lattice c	7.174 Å	1273 (<)	SiO2 IIb (coesite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 11 report
Lattice c	8.36 Å	1368	SiO2 (silica W) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 13 report
lattice beta	120.33 °		SiO2 IIb (coesite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 11 report
lattice beta	120.1 °	838	SiO2 II (coesite) alloy: Si 0.333333	unspecified	[3] Schnurre 2004	Table 1, p. 5, row 10 report

Other property (2)

Other property, O–Si system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Other printed: P	11 mbar	1689	SiO2 (L)	model	[3] Schnurre 2004	p. 19 report	At constant 11 mbar total pressure this shift is from 1693 K (stable) to 1689 K (metastable, with SiO2 (L)).
Other printed: P	11 mbar	1693		model	[3] Schnurre 2004	p. 19 report	At constant 11 mbar total pressure this shift is from 1693 K (stable) to 1689 K (metastable, with SiO2 (L)).

Sources

Reporting papers the values were read from (a value cited from another work names that work in its row).

Bengt Hallstedt, Thermodynamic assessment of the Silicon — Oxygen system, Calphad 16, 53-61 (1992). doi:10.1016/0364-5916(92)90038-y
Dongwon Shin, Raymundo Arróyave, Zi-Kui Liu, Thermodynamic modeling of the Hf–Si–O system, Calphad 30, 375-386 (2006). doi:10.1016/j.calphad.2006.08.006
S.M. Schnurre, J. Gröbner, R. Schmid-Fetzer, Thermodynamics and phase stability in the Si–O system, Journal of Non-Crystalline Solids 336, 1-25 (2004). doi:10.1016/j.jnoncrysol.2003.12.057

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-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD) (version 2026.10), Zenodo (2026). doi:10.5281/zenodo.23735891
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); 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_hulls_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD)}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735891},
  url       = {https://doi.org/10.5281/zenodo.23735891}
}

@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}
}