C–W system

32 accepted literature values from 2 paper(s) (experimental 12, model 20); 0 calculated phase diagram(s). 8 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV.

Data: JSON · CSV · interactive explorer · phases (7) · papers (bibliography) · Markdown

Accepted values by evidence class
Evidence class	Values
experimental	12
model	20

Accepted values by property group
Property group	Values
invariant reaction	24
phase transition	1
formation	3
heat capacity / entropy / enthalpy	4

Convex hulls: Materials Project DFT hull · OQMD DFT hull · CALPHAD hull WC-86Gus

Invariant reactions (literature)

Invariant reactions reported in the literature for the C–W system (24)
T (K)	Reaction / phases	Compositions (mole fraction)	Class	Source	Location
3051	congruent melting: L-> hcp	L: C 0.31; hcp: C 0.31	model	[1] He 2022 cites Gustafson 1986 doi	Table 3, p. 4, row 5 report
3051	congruent melting: L-> hcp	L: C 0.31; hcp: C 0.31	model	[1] He 2022	Table 3, p. 4, row 6 report
3049	L+graphite -> WC	L: C 0.42; graphite: C 1; WC: C 0.5	experimental	[1] He 2022 cites Rudy 1969	Table 3, p. 4, row 16 report
3048	congruent melting: L-> hcp	L: C 0.31; hcp: C 0.31	experimental	[1] He 2022 cites Rudy 1969	Table 3, p. 4, row 4 report
3047	L+graphite -> WC	L: C 0.421; graphite: C 1; WC: C 0.5	model	[1] He 2022 cites Gustafson 1986 doi	Table 3, p. 4, row 17 report
3045	L+graphite -> WC	L: C 0.423; graphite: C 1; WC: C 0.5	model	[1] He 2022	Table 3, p. 4, row 18 report
3020	congruent melting: L->fcc	L: C 0.39; fcc: C 0.39	experimental	[1] He 2022 cites Rudy 1969	Table 3, p. 4, row 10 report
3008	eutectic: L->hcp+fcc	L: C 0.365; hcp: C 0.345; fcc: C 0.375	experimental	[1] He 2022 cites Rudy 1969	Table 3, p. 4, row 7 report
3006	eutectic: L->hcp+fcc	L: C 0.37; hcp: C 0.323; fcc: C 0.371	model	[1] He 2022	Table 3, p. 4, row 9 report
3006	congruent melting: L->fcc	L: C 0.373; fcc: C 0.376	model	[1] He 2022	Table 3, p. 4, row 12 report
3005	congruent melting: L->fcc	L: C 0.374; fcc: C 0.374	model	[1] He 2022 cites Gustafson 1986 doi	Table 3, p. 4, row 11 report
3004	eutectic: L->hcp+fcc	L: C 0.369; hcp: C 0.323; fcc: C 0.372	model	[1] He 2022 cites Gustafson 1986 doi	Table 3, p. 4, row 8 report
3002	eutectic: L-> fcc+WC	L: C 0.396; fcc: C 0.387; WC: C 0.5	model	[1] He 2022 cites Gustafson 1986 doi	Table 3, p. 4, row 14 report
3002	eutectic: L-> fcc+WC	L: C 0.398; fcc: C 0.388; WC: C 0.5	model	[1] He 2022	Table 3, p. 4, row 15 report
2993	eutectic: L-> fcc+WC	L: C 0.41; fcc: C 0.395; WC: C 0.495	experimental	[1] He 2022 cites Rudy 1969	Table 3, p. 4, row 13 report
2983	eutectic: L->bcc+hcp	L: C 0.22; bcc: C 0.01; hcp: C 0.256	experimental	[1] He 2022 cites Rudy 1969	Table 3, p. 4, row 1 report
2983	eutectic: L->bcc+hcp	L: C 0.2224; bcc: C 0.01; hcp: C 0.267	model	[1] He 2022	Table 3, p. 4, row 3 report
2980	eutectic: L->bcc+hcp	L: C 0.2285; bcc: C 0.007; hcp: C 0.273	model	[1] He 2022 cites Gustafson 1986 doi	Table 3, p. 4, row 2 report
2803	fcc-> hcp+WC	fcc: C 0.38; hcp: C 0.334; WC: C 0.494	experimental	[1] He 2022 cites Rudy 1969	Table 3, p. 4, row 19 report
2803	fcc-> hcp+WC	fcc: C 0.38; hcp: C 0.325; WC: C 0.5	model	[1] He 2022	Table 3, p. 4, row 21 report
2801	fcc-> hcp+WC	fcc: C 0.38; hcp: C 0.325; WC: C 0.5	model	[1] He 2022 cites Gustafson 1986 doi	Table 3, p. 4, row 20 report
1525	hcp->bcc+WC	hcp: C 0.321; WC: C 0.5	model	[1] He 2022 cites Gustafson 1986 doi	Table 3, p. 4, row 23 report
1523	hcp->bcc+WC	hcp: C 0.328; WC: C 0.5	model	[1] He 2022	Table 3, p. 4, row 24 report
1523	hcp->bcc+WC	hcp: C 0.326; WC: C 0.5	experimental	[1] He 2022 cites Kurlov 2006 doi	Table 3, p. 4, row 22 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, C–W system (3)
Phase	Compound	Value	T (K)	Class	MP DFT (kJ/mol-atom)	OQMD DFT (kJ/mol-atom)	Source	Location
WC		-40170 per formula unit ± 1700	298.15	experimental			[1] He 2022 cites McGraw 1947 doi	Table 2, p. 3, row 4 report
WC	WC	-20.0887 kJ/mol-atom	298.15	model	-11.742 (mp-aaaaacuw)	-12.124 (oqmd-3084)	[1] He 2022 cites Gustafson 1986 doi	Table 2, p. 3, row 5 report
WC	WC	-20.0852 kJ/mol-atom	298.15	model	-11.742 (mp-aaaaacuw)	-12.124 (oqmd-3084)	[1] He 2022	Table 2, p. 3, row 6 report

Other properties

Phase transition (1)

Phase transition, C–W system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Phase transition	3020 K	3020	congruent transformation	experimental	[2] Gustafson 1986	p. 3 report	Rudy et al. show peritectic melting of WC at 3049 ± 4 K in contact with graphite while WC1-x melts congruently at 3020± 12 K.

Heat capacity / entropy / enthalpy (4)

Heat capacity / entropy / enthalpy, C–W system
Property	Value	T (K)	Phases / composition	Class	Source	Location	Quote
Entropy printed: S^WC(298)	16.045 J/mol-atom/K	298.15	WC alloy: W 0.5	experimental	[1] He 2022 cites McGraw 1947 doi	Table 2, p. 3, row 1 report
Entropy printed: S^WC(298)	16.05 J/mol-atom/K	298.15	WC alloy: W 0.5	model	[1] He 2022	Table 2, p. 3, row 3 report
Entropy printed: S^WC(298)	16.045 J/mol-atom/K	298.15	WC alloy: W 0.5	model	[1] He 2022 cites Gustafson 1986 doi	Table 2, p. 3, row 2 report
Entropy printed: standard entropy	159.8 J/(mol K)	1000	W2 C0.833 (hcp)	experimental	[1] He 2022 cites Grnvold 1988 doi	p. 3 report	Grønvold et al. [40] determined the standard entropy of W2 C0.833 (hcp) to be 75.80 J/(mol K) at 298.15 K and 159.8 J/(mol K) at 1000 K.

Sources

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

Zhangting He, Malin Selleby, A third generation Calphad description of W–C including a revision of liquid C, Calphad 78, 102449 (2022). doi:10.1016/j.calphad.2022.102449
P. Gustafson, Thermodynamic evaluation of C–W system, Materials Science and Technology 2, 653-658 (1986). doi:10.1179/mst.1986.2.7.653

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}
}