P–Si system

69 accepted literature values from 3 paper(s) (experimental 33, model 27, unspecified 9); 0 calculated phase diagram(s). 12 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV.

Data: JSON · CSV · interactive explorer · phases (10) · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
experimental	33
model	27
unspecified	9

Accepted values by property group
Property group	Values
invariant reaction	20
phase transition	4
phase equilibrium	7
formation	14
heat capacity / entropy / enthalpy	12
activity / EMF / Gibbs energy	5
crystal structure	6
model expression	1

Convex hulls: Materials Project DFT hull · OQMD DFT hull · CALPHAD hull SiP-04Din-LB · CALPHAD hull SiP-14Lia · CALPHAD hull SiP-21Don

Invariant reactions (literature)

Invariant reactions reported in the literature for the P–Si system (20)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location
1451.15	other: Congruent melting L = SiP2	L: P 0.666667, Si 0.333333; SiP2: P 0.666667, Si 0.333333	experimental	[1] Liang 2014 cites Ugai 1987	Table 4, p. 7, row 11 report
1443.15	other: Congruent melting L = SiP	L: P 0.5, Si 0.5; SiP: P 0.5, Si 0.5	experimental	[1] Liang 2014 cites Ugai 1987	Table 4, p. 7, row 7 report
1442.15	other: Congruent melting L = SiP2	L: P 0.666667, Si 0.333333; SiP2: P 0.666667, Si 0.333333	model	[1] Liang 2014	Table 4, p. 7, row 13 report
1434.15	other: Congruent melting L = SiP	L: P 0.5, Si 0.5; SiP: P 0.5, Si 0.5	model	[1] Liang 2014	Table 4, p. 7, row 10 report
1430.15	eutectic: Eutectic L = SiP + SiP2	SiP: P 0.5, Si 0.5 (basis unresolved); SiP2: P 0.666667, Si 0.333333 (basis unresolved)	model	[1] Liang 2014	Table 4, p. 7, row 16 report
1429.15	other: Congruent melting L = SiP2	L: P 0.666667, Si 0.333333; SiP2: P 0.666667, Si 0.333333	model	[1] Liang 2014 cites Jung 2012 doi	Table 4, p. 7, row 12 report
1412.15	other: Congruent melting L = SiP	L: P 0.5, Si 0.5; SiP: P 0.5, Si 0.5	experimental	[1] Liang 2014 cites Safarian 2011 doi	Table 4, p. 7, row 8 report
1410.15	other: Congruent melting L = SiP	L: P 0.5, Si 0.5; SiP: P 0.5, Si 0.5	model	[1] Liang 2014 cites Jung 2012 doi	Table 4, p. 7, row 9 report
1407.15	eutectic: Eutectic L = (Si) + SiP	SiP: P 0.5, Si 0.5 (basis unresolved)	model	[1] Liang 2014	Table 4, p. 7, row 6 report
1407.15	eutectic: Eutectic L = SiP + SiP2	SiP: P 0.5, Si 0.5; SiP2: P 0.666667, Si 0.333333	model	[1] Liang 2014 cites Jung 2012 doi	Table 4, p. 7, row 15 report
1404.15	eutectic: Eutectic L = (Si) + SiP	SiP: P 0.5, Si 0.5 (basis unresolved)	model	[1] Liang 2014	Table 4, p. 7, row 5 report
1404.15	eutectic: Eutectic L = (Si) + SiP	L: P 0.32807, Si 0.67193; SiP: P 0.5, Si 0.5	experimental	[1] Liang 2014 cites Giessen 1959	Table 4, p. 7, row 1 report
1404.15	eutectic: Eutectic L = (Si) + SiP	SiP: P 0.5, Si 0.5	experimental	[1] Liang 2014 cites Ugai 1987	Table 4, p. 7, row 2 report
1404	eutectic: Si-SiP-liq. eutectic	SiP: P 0.5	unspecified	[2] Favre 2024 cites ref. 12	Table 9, p. 50, row 2 report
1404	eutectic: Si-SiP-liq. eutectic	SiP: P 0.5	unspecified	[2] Favre 2024 cites as well as Safarian and Tangstad[6] namely for liquidus retained data	Table 9, p. 50, row 1 report
1402.15	eutectic: Eutectic L = (Si) + SiP	SiP: P 0.5, Si 0.5 (basis unresolved)	experimental	[1] Liang 2014 cites Safarian 2011 doi	Table 4, p. 7, row 3 report
1402	eutectic: Si-SiP-liq. eutectic	SiP: P 0.5	unspecified	[2] Favre 2024 cites ref. 6	Table 9, p. 50, row 4 report
1400.15	eutectic: Eutectic L = (Si) + SiP	SiP: P 0.5, Si 0.5 (basis unresolved)	model	[1] Liang 2014 cites Jung 2012 doi	Table 4, p. 7, row 4 report
1400	eutectic: Si-SiP-liq. eutectic	SiP: P 0.5	experimental	[2] Favre 2024 cites values for SiP and – (ii) Philipp and Schmidt [59] for SiP2	Table 9, p. 50, row 3 report
1398.15	eutectic: Eutectic L = SiP + SiP2	SiP: P 0.5, Si 0.5; SiP2: P 0.666667, Si 0.333333	experimental	[1] Liang 2014 cites Ugai 1987	Table 4, p. 7, row 14 report

Formation enthalpies

Literature values in kJ/mol-atom where the per-atom basis is known. DFT columns: the lowest-energy entry at the same composition (Materials Project 2026.04.13, OQMD v1.8; different energy references, never averaged), from dft_parity.json.

Enthalpies of formation, P–Si system (14)
Phase	Compound	Value	T (K)	Class	MP DFT (kJ/mol-atom)	OQMD DFT (kJ/mol-atom)	Source	Location
SiP	SiP	-39.52 kJ/mol-atom	298.15	unspecified	-13.047 (mp-aaaaaedq)	-26.653 (oqmd-1784005)	[1] Liang 2014 cites ref. 1938Bil	Table 5, p. 8, row 3 report
SiP	SiP	-37.6 kJ/mol-atom	298.15	unspecified	-13.047 (mp-aaaaaedq)	-26.653 (oqmd-1784005)	[1] Liang 2014 cites ref. 1976Kor	Table 5, p. 8, row 4 report
SiP	SiP	-31.65 kJ/mol-atom	298.15	model	-13.047 (mp-aaaaaedq)	-26.653 (oqmd-1784005)	[1] Liang 2014	Table 5, p. 8, row 7 report
SiP	SiP	-31.65 kJ/mol-atom	298.15	model	-13.047 (mp-aaaaaedq)	-26.653 (oqmd-1784005)	[1] Liang 2014 cites ref. 2012Jun	Table 5, p. 8, row 6 report
SiP	SiP	-31.61 kJ/mol-atom	298.15	model	-13.047 (mp-aaaaaedq)	-26.653 (oqmd-1784005)	[1] Liang 2014 cites ref. 2011Aru	Table 5, p. 8, row 5 report
SiP	SiP	-30.95 kJ/mol-atom	298.15	unspecified	-13.047 (mp-aaaaaedq)	-26.653 (oqmd-1784005)	[1] Liang 2014 cites ref. 1977Bar	Table 5, p. 8, row 2 report
SiP(liq)		-63.746 kJ/mol (basis unstated)	1443	model			[2] Favre 2024 cites ref. 11	Table 3, p. 35, row 1 report
SiP(liq)		-46.893 kJ/mol (basis unstated)	1443	model			[2] Favre 2024 cites ref. 11	Table 3, p. 35, row 2 report
SiP(liq)		36.202 kJ/mol (basis unstated)	1418	model			[2] Favre 2024	Table 3, p. 35, row 3 report
SiP(s)		-246.525 kJ/mol (basis unstated)	1443	model			[2] Favre 2024 cites ref. 11	Table 3, p. 35, row 1 report
SiP(s)		-147.253 kJ/mol (basis unstated)	1443	model			[2] Favre 2024 cites ref. 11	Table 3, p. 35, row 2 report
SiP(s)		-66.425 kJ/mol (basis unstated)	1418	model			[2] Favre 2024	Table 3, p. 35, row 3 report
SiP2	SiP2	-26.69 kJ/mol-atom	298.15	model	-12.072 (mp-aaaaaoum)	-27.964 (oqmd-7989)	[1] Liang 2014	Table 5, p. 8, row 9 report
SiP2	SiP2	-26.43 kJ/mol-atom	298.15	model	-12.072 (mp-aaaaaoum)	-27.964 (oqmd-7989)	[1] Liang 2014 cites ref. 2012Jun	Table 5, p. 8, row 8 report

Other properties

Phase transition (4)

Phase transition, P–Si system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Phase transition	1237.15 K	1237.15	other	experimental	[1] Liang 2014	p. 2 report	Differential thermal analysis in static air from room temperature to 1015 C shows heating signals in the range 964-990 C but no thermal activity was seen upon cooling.
Phase transition	1375 K	1375	other	model	[2] Favre 2024	p. 48 report	We observed that applying a 1 bar pressure, the SiP compound decomposes at 1375K before melting - equilibrium with 1 bar pressure of P2(g) + P4(g).
Phase transition	1410.15 K	1410.15	congruent melting	model	[1] Liang 2014 cites Jung 2012 doi	p. 9 report	They chose 1137 C as congruent melting temperature of SiP, but it is noted that the pressure-discrepancy increases in their Gas + SiP + liquid range.[5]
Phase transition	1443.15 K	1443.15	congruent melting	experimental	[1] Liang 2014 cites Ugai 1987	p. 9 report	It was found impossible to reconcile in a consistent thermodynamic assessment the experimentally determined[34] high congruent melting temperature of SiP (1170 C, Fig. 2) with the low experimental pressure value at that point from the same group of authors[26] (2.7 bar, Fig. 4); the calculated values are 1161 C and 13 bar.

Phase equilibrium (7)

Phase equilibrium, P–Si system
Property	T (K)	Phases / composition	Class	Source	Location
Phase composition	823	Si + (Si) Si: P 0.0011, Si 0.9989; (Si): P 0.0011, Si 0.9989	experimental	[2] Favre 2024 cites ref. 22	Table 2, p. 20, row 6 report
Phase composition	923	Si + (Si) Si: P 0.0013, Si 0.9987; (Si): P 0.0013, Si 0.9987	experimental	[2] Favre 2024 cites ref. 22	Table 2, p. 20, row 7 report
Phase composition	973	Si + (Si) Si: P 0.0014, Si 0.9986; (Si): P 0.0014, Si 0.9986	experimental	[2] Favre 2024 cites ref. 16	Table 2, p. 20, row 1 report
Phase composition	1073	Si + (Si) Si: P 0.0032, Si 0.9968; (Si): P 0.0032, Si 0.9968	experimental	[2] Favre 2024 cites ref. 16	Table 2, p. 20, row 2 report
Phase composition	1173	Si + (Si) Si: P 0.0045, Si 0.9955; (Si): P 0.0045, Si 0.9955	experimental	[2] Favre 2024 cites ref. 16	Table 2, p. 20, row 3 report
Phase composition	1273	Si + (Si) Si: P 0.005, Si 0.995; (Si): P 0.005, Si 0.995	experimental	[2] Favre 2024 cites ref. 16	Table 2, p. 20, row 4 report
Phase composition	1473	Si + (Si) Si: P 0.0043, Si 0.9957; (Si): P 0.0043, Si 0.9957	experimental	[2] Favre 2024 cites ref. 16	Table 2, p. 20, row 5 report

Heat capacity / entropy / enthalpy (12)

Heat capacity / entropy / enthalpy, P–Si system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Entropy printed: S°298(SiP, est.)	65 J/mol (basis unstated)/K	298 (>)	SiP alloy: Si 0.5	experimental	[2] Favre 2024 cites ref. 59	Table 6, p. 44, row 3 report
Entropy printed: S°298(SiP)	34.78 J/mol (basis unstated)/K	298.15	SiP alloy: Si 0.5	experimental	[2] Favre 2024 cites ref. 55	Table 6, p. 44, row 2 report
Entropy printed: S°298	6.3 J/mol-atom/K	298.15	SiP alloy: Si 0.5	unspecified	[1] Liang 2014 cites ref. 1938Bil	Table 5, p. 8, row 3 report
Entropy printed: S°298	14.7 J/mol-atom/K	298.15	SiP alloy: Si 0.5	model	[1] Liang 2014 cites ref. 2011Aru	Table 5, p. 8, row 5 report
Entropy printed: S°298	17.37 J/mol-atom/K	298.15	SiP alloy: Si 0.5	model	[1] Liang 2014	Table 5, p. 8, row 7 report
Entropy printed: S°298	16.3 J/mol-atom/K	298.15	SiP alloy: Si 0.5	unspecified	[1] Liang 2014 cites ref. 1977Bar	Table 5, p. 8, row 2 report
Entropy printed: S°298	7.95 J/mol-atom/K	298.15	SiP alloy: Si 0.5	unspecified	[1] Liang 2014 cites ref. 1976Kor	Table 5, p. 8, row 4 report
Entropy printed: S°298	17.37 J/mol-atom/K	298.15	SiP alloy: Si 0.5	experimental	[1] Liang 2014 cites ref. 1979Uga	Table 5, p. 8, row 1 report
Entropy printed: S°298	17.37 J/mol-atom/K	298.15	SiP alloy: Si 0.5	model	[1] Liang 2014 cites ref. 2012Jun	Table 5, p. 8, row 6 report
Entropy printed: S°298	22.33 J/mol-atom/K	298.15	SiP2 alloy: Si 0.333333	model	[1] Liang 2014 cites ref. 2012Jun	Table 5, p. 8, row 8 report
Entropy printed: S°298	21.35 J/mol-atom/K	298.15	SiP2 alloy: Si 0.333333	model	[1] Liang 2014	Table 5, p. 8, row 9 report
Heat capacity printed: C°p(SiP, 298 K)	35.23 J/mol (basis unstated)/K	298.15	SiP alloy: Si 0.5	experimental	[2] Favre 2024 cites ref. 55	Table 6, p. 44, row 2 report

Activity / EMF / Gibbs energy (5)

Activity / EMF / Gibbs energy, P–Si system
Property	Value	T (K)	Class	Source	Location	Quote
Vapour pressure printed: p	3.37 bar	1398	experimental	[2] Favre 2024	p. 29 report	Eutectic temperature between the two compounds is 1398K and 3.37 bar obtained by extrapolation.
Vapour pressure printed: p	0.944 bar	1400	experimental	[2] Favre 2024	p. 29 report	A minimum temperature as extrapolated corresponds to the eutectic between Si and SiP is at about 1400 K for 0.944 bar according to their original graph.
Vapour pressure printed: p	2.5 bar	1439	experimental	[2] Favre 2024 cites ref. 45	p. 29 report	The maximum temperature would correspond to the congruent melting point of SiP that is observed at 1439 ± 5 K for 2.5 bar a pressure composed mainly by P2(g) + P4(g).
Vapour pressure printed: total pressure	2.7 bar	1443	experimental	[2] Favre 2024	p. 29 report	Full results allow the authors to propose the melting temperature of the two compounds as well as their total pressure in equilibrium: for SiP 1443K and 2.7 bar and for SiP2 1451K and 3.7 bar.
Vapour pressure printed: total pressure	3.7 bar	1451	experimental	[2] Favre 2024	p. 29 report	Full results allow the authors to propose the melting temperature of the two compounds as well as their total pressure in equilibrium: for SiP 1443K and 2.7 bar and for SiP2 1451K and 3.7 bar.

Crystal structure (6)

Crystal structure, P–Si system
Property	Value	T (K)	Phases / composition	Class	Source	Location
Lattice a	20.49 Å	298.15	SiP alloy: Si 0.5	experimental	[3] Liu 2016 cites Wadsten 1975	Table 1, p. 3, row 1 report
Lattice a	13.97 Å	298.15	SiP2 alloy: Si 0.333333	experimental	[3] Liu 2016 cites Wadsten 1967 doi	Table 1, p. 3, row 2 report
Lattice b	13.61 Å	298.15	SiP alloy: Si 0.5	experimental	[3] Liu 2016 cites Wadsten 1975	Table 1, p. 3, row 1 report
Lattice b	10.08 Å	298.15	SiP2 alloy: Si 0.333333	experimental	[3] Liu 2016 cites Wadsten 1967 doi	Table 1, p. 3, row 2 report
Lattice c	3.51 Å	298.15	SiP alloy: Si 0.5	experimental	[3] Liu 2016 cites Wadsten 1975	Table 1, p. 3, row 1 report
Lattice c	3.43 Å	298.15	SiP2 alloy: Si 0.333333	experimental	[3] Liu 2016 cites Wadsten 1967 doi	Table 1, p. 3, row 2 report

Model expression (1)

Model expression, P–Si system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Heat capacity printed: C°p(SiP2)	expression: 67.02 + 17.14·10^-3 T	298 (>)	SiP2	experimental	[2] Favre 2024 cites ref. 59	Table 6, p. 44, row 3 report

Sources

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

Song-Mao Liang, Rainer Schmid-Fetzer, Modeling of Thermodynamic Properties and Phase Equilibria of the Si-P System, J. Phase Equilib. Diffus. 35, 24-35 (2014). doi:10.1007/s11669-013-0269-3
Simon Favre, Ioana Nuta, Guy Chichignoud, Evelyne Fischer, Christian Chatillon, Critical assessment of the Si-P system: P solubility in the Si-rich region and refining by phosphorus distillation, Calphad 87, 102758 (2024). doi:10.1016/j.calphad.2024.102758
Ya Liu, Bin Zhou, Wei Lv, Changjun Wu, Xuping Su, Jianhua Wang, Experimental investigation and thermodynamic assessment of the Zn–Si–P system, Surface and Coatings Technology 306, 370-377 (2016). doi:10.1016/j.surfcoat.2016.01.016

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}
}