# C system

> C system: 26 accepted literature values (heat capacity / entropy / enthalpy 15, crystal structure 6, other property 3, mixing / partial 2) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

HTML: https://data.orchid-project.org/systems/C.html · Markdown: https://data.orchid-project.org/systems/C.md

26 accepted literature values from 3 paper(s) (experimental 8, model 10, unspecified 8); 0 calculated phase diagram(s).

Data: [JSON](https://data.orchid-project.org/literature/systems/C.json) · [CSV](https://data.orchid-project.org/systems/C.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#C) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/C.html) · [Markdown](https://data.orchid-project.org/systems/C.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 8 |
| model | 10 |
| unspecified | 8 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| mixing / partial | 2 |
| heat capacity / entropy / enthalpy | 15 |
| crystal structure | 6 |
| other property | 3 |

## Other properties

### Mixing / partial (2)

Table: Mixing / partial, C system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Partial enthalpy; _printed: H_C^liq(T_m) - H_C^gra(T_m)_ | 125.52 kJ/mol (basis unstated) |  | liquid C | experimental | [1] He 2021; _cites Leider 1973_ [doi](https://doi.org/10.1016/0008-6223%2873%2990316-3) | Table 2, p. 3, row 3; `ORC-BFNDNQBZFR` |  |
| Partial enthalpy; _printed: H_C^liq(T_m) - H_C^gra(T_m)_ | 117.318 kJ/mol (basis unstated) |  | liquid C | unspecified | [1] He 2021 | Table 2, p. 3, row 4; `ORC-E26GRJJGOA` |  |

### Heat capacity / entropy / enthalpy (15)

Table: Heat capacity / entropy / enthalpy, C system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Entropy; _printed: S_C^liq(Tm) − S_C^gra(Tm)_ | 24.6 J/mol (basis unstated)/K |  | liquid | experimental | [2] He 2022; _cites Gokcen 1976_ | Table 1, p. 2, row 7; `ORC-5WHLNXHGCH.970a49` |  |
| Entropy; _printed: S_C^liq(Tm) − S_C^gra(Tm)_ | 24.6 J/mol (basis unstated)/K |  | liquid | model | [2] He 2022; _cites He 2021_ [doi](https://doi.org/10.1016/j.calphad.2021.102250) | Table 1, p. 2, row 8; `ORC-D3EUPQIIFA.98c686` |  |
| Entropy; _printed: S_C^liq(Tm) − S_C^dia(Tm)_ | 30.5 J/mol (basis unstated)/K |  | liquid | model | [2] He 2022; _cites He 2021_ [doi](https://doi.org/10.1016/j.calphad.2021.102250) | Table 1, p. 2, row 16; `ORC-GH2ZVOLLR6.0ffc6e` |  |
| Entropy; _printed: S_C^liq(Tm) − S_C^gra(Tm)_ | 24.85 J/mol (basis unstated)/K |  | liquid | model | [2] He 2022 | Table 1, p. 2, row 9; `ORC-KA2FANSBS6.c711c7` |  |
| Entropy; _printed: S_C^liq(Tm) − S_C^dia(Tm)_ | 30.73 J/mol (basis unstated)/K |  | liquid | model | [2] He 2022 | Table 1, p. 2, row 17; `ORC-KLA5OE5T6S.433bde` |  |
| Entropy; _printed: S_C^liq(Tm) − S_C^dia(Tm)_ | 29.3 J/mol (basis unstated)/K |  | liquid | experimental | [2] He 2022; _cites Gokcen 1976_ | Table 1, p. 2, row 15; `ORC-VCS4REBGES.a2d3ba` |  |
| Entropy; _printed: S_C^liq(T_m) - S_C^gra(T_m)_ | 24.6 J/mol (basis unstated)/K |  | liquid C | experimental | [1] He 2021; _cites Spencer 1976_ | Table 2, p. 3, row 5; `ORC-6SVCVBRPL5.722a37` |  |
| Entropy; _printed: S_C^liq(T_m) - S_C^gra(T_m)_ | 24.6 J/mol (basis unstated)/K |  | liquid C | unspecified | [1] He 2021 | Table 2, p. 3, row 6; `ORC-7CBHVZXCFM.8b4553` |  |
| Entropy; _printed: S_C^liq(T_m) - S_C^dia(T_m)_ | 30.5 J/mol (basis unstated)/K |  | liquid C | unspecified | [1] He 2021 | Table 2, p. 3, row 11; `ORC-I3JYXLQULN.3229c8` |  |
| Entropy; _printed: S_C^liq(T_m) - S_C^dia(T_m)_ | 29.3 J/mol (basis unstated)/K |  | liquid C | experimental | [1] He 2021; _cites Spencer 1976_ | Table 2, p. 3, row 10; `ORC-KARM7L3GZH.5eb50e` |  |
| Heat capacity; _printed: C_P^liq(T_m)_ | 28 J/mol (basis unstated)/K |  | liq | experimental | [2] He 2022; _cites Chase 1982_ | Table 1, p. 2, row 10; `ORC-2HTVGR5V3Q.e9ae96` |  |
| Heat capacity; _printed: C_P^liq(T_m)_ | 28.72 J/mol (basis unstated)/K |  | liq | model | [2] He 2022 | Table 1, p. 2, row 12; `ORC-SFAXXSKD2R.d5ab83` |  |
| Heat capacity; _printed: C_P^liq(T_m)_ | 28 J/mol (basis unstated)/K |  | liq | model | [2] He 2022; _cites He 2021_ [doi](https://doi.org/10.1016/j.calphad.2021.102250) | Table 1, p. 2, row 11; `ORC-V4NLBMJ3UG.695fe4` |  |
| Heat capacity; _printed: C_P^liq(T_m)_ | 28 J/mol (basis unstated)/K |  | liquid C | unspecified | [1] He 2021 | Table 2, p. 3, row 8; `ORC-QMVLTSFUWB.c4546f` |  |
| Heat capacity; _printed: C_P^liq(T_m)_ | 28 J/mol (basis unstated)/K |  | liquid C | experimental | [1] He 2021; _cites Valenzuela 1982_ [doi](https://doi.org/10.1063/1.555666) | Table 2, p. 3, row 7; `ORC-WT4JP4ECPI.5db96b` |  |

### Crystal structure (6)

Table: Crystal structure, C system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 2.4612 Å | 298.15 | C; _alloy: C 1_ | model | [3] Duschanek 1995; _cites Massalski 1990_ | Table 3, p. 4, row 3; `ORC-KHEWPOB62Y.5e2dc1` |  |
| Lattice a | 2.464 Å | 2909.15 | C; _alloy: C 1_ | unspecified | [3] Duschanek 1995; _cites ref. 66Rud_ | Table 3, p. 4, row 5; `ORC-UFH3AWMGOP.da96d7` |  |
| Lattice a | 2.464 Å | 3111.15 | C; _alloy: C 1_ | unspecified | [3] Duschanek 1995; _cites ref. 66Rud_ | Table 3, p. 4, row 4; `ORC-NIJARPXLOB.9856d5` |  |
| Lattice c | 6.709 Å | 298.15 | C; _alloy: C 1_ | model | [3] Duschanek 1995; _cites Massalski 1990_ | Table 3, p. 4, row 3; `ORC-KHEWPOB62Y.7ddd1a` |  |
| Lattice c | 6.714 Å | 2909.15 | C; _alloy: C 1_ | unspecified | [3] Duschanek 1995; _cites ref. 66Rud_ | Table 3, p. 4, row 5; `ORC-UFH3AWMGOP.ec5be5` |  |
| Lattice c | 6.72 Å | 3111.15 | C; _alloy: C 1_ | unspecified | [3] Duschanek 1995; _cites ref. 66Rud_ | Table 3, p. 4, row 4; `ORC-NIJARPXLOB.f3ec89` |  |

### Other property (3)

Table: Other property, C system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Transition enthalpy; _printed: H_C^liq(Tm) − H_C^gra(Tm)_ | 117318 J/mol |  | liquid | model | [2] He 2022; _cites He 2021_ [doi](https://doi.org/10.1016/j.calphad.2021.102250) | Table 1, p. 2, row 5; `ORC-K7CKD2RXYP` |  |
| Transition enthalpy; _printed: H_C^liq(Tm) − H_C^gra(Tm)_ | 118644 J/mol |  | liquid | model | [2] He 2022 | Table 1, p. 2, row 6; `ORC-V24JGGZ4AM` |  |
| Transition enthalpy; _printed: H_C^liq(Tm) − H_C^gra(Tm)_ | 125520 J/mol |  | liquid | experimental | [2] He 2022; _cites Leider 1973_ [doi](https://doi.org/10.1016/0008-6223%2873%2990316-3) | Table 1, p. 2, row 4; `ORC-ZZD5AKU2OA` |  |

## Sources

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

1. Zhangting He, Bartek Kaplan, Huahai Mao, Malin Selleby, The third generation Calphad description of Al–C including revisions of pure Al and C, Calphad 72, 102250 (2021). [doi:10.1016/j.calphad.2021.102250](https://doi.org/10.1016/j.calphad.2021.102250)
2. 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](https://doi.org/10.1016/j.calphad.2022.102449)
3. H. Duschanek, P. Rogl, H. L. Lukas, A critical assessment and thermodynamic calculation of the boron-carbon-titanium (B-C-Ti) ternary system, JPE 16, 46-60 (1995). [doi:10.1007/bf02646248](https://doi.org/10.1007/bf02646248)

## 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). https://doi.org/10.5281/zenodo.23735569
- R. Arróyave, J. Saal, D. Shin, ORCHID data: umbrella record of the ORCHID datasets (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/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); 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; 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).

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.

```bibtex
@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_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}
}
```

---

Derived data CC BY 4.0 ([licence](https://creativecommons.org/licenses/by/4.0/)): cite ORCHID ([CITATION.cff](https://data.orchid-project.org/CITATION.cff)) and the original sources. Quotes are short excerpts kept so that each value can be checked; they remain under the publishers' copyright and are not relicensed. Source papers, page images and full text are not redistributed. Field reference: [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt). Found an error? The report link of a value (Markdown: its id, ORC-..., in the Location column) opens a pre-filled GitHub issue, https://github.com/orchid-calphad/orchid-data/issues/new?template=report-value-error.yml&record_id=\<id>, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).