# C–Ce system

> C–Ce system: 18 accepted literature values (formation 9, crystal structure 5, invariant reaction 4) 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-CE.html · Markdown: https://data.orchid-project.org/systems/C-CE.md

18 accepted literature values from 1 paper(s) (experimental 16, model 2); 0 calculated phase diagram(s).

Data: [JSON](https://data.orchid-project.org/literature/systems/C-CE.json) · [CSV](https://data.orchid-project.org/systems/C-CE.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#C-CE) · [phases (10)](https://data.orchid-project.org/phases/pages/C-CE.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/C-CE.html) · [Markdown](https://data.orchid-project.org/systems/C-CE.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 16 |
| model | 2 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| invariant reaction | 4 |
| formation | 9 |
| crystal structure | 5 |

Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/C/C-CE.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/C/C-CE.json)

## Invariant reactions (literature)

Table: Invariant reactions reported in the literature for the C–Ce system (4)

| T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote |
|---:|---|---|---|---|---|---|
| 1373.15 | βCeC2 + (C) \<-> αCeC2 |  | experimental | [1] Peng 2011; _cites Winchell 1967_ [doi](https://doi.org/10.1021/j100872a050) | Table 4, p. 6, row 20; `ORC-5C3XLYMH7A` |  |
| 1373.15 | βCeC2 \<-> Ce2C3 + αCeC2 |  | experimental | [1] Peng 2011; _cites Winchell 1967_ [doi](https://doi.org/10.1021/j100872a050) | Table 4, p. 6, row 22; `ORC-HTYBPDQL2W` |  |
| 1372.95 | βCeC2 \<-> Ce2C3 + αCeC2 | βCeC2: C 0.667; Ce2C3: C 0.6; αCeC2: C 0.667 | model | [1] Peng 2011 | Table 4, p. 6, row 21; `ORC-3MFQV3T3W5` |  |
| 1372.95 | βCeC2 + (C) \<-> αCeC2 | βCeC2: C 0.667; (C): C 1; αCeC2: C 0.667 | model | [1] Peng 2011 | Table 4, p. 6, row 19; `ORC-ITKYX3YG5T` |  |

## 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](https://data.orchid-project.org/literature/dft_parity.json).

Table: Enthalpies of formation, C–Ce system (9)

| Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote |
|---|---|---:|---:|---|---:|---:|---|---|---|
| Ce2C3 | [Ce2C3](https://data.orchid-project.org/compounds/Ce2C3.html) | -35.3 kJ/mol-atom ± 1.1 | 298.15 | experimental | -24.666 (mp-aaaabdwf) | -11.083 (oqmd-13369) | [1] Peng 2011; _cites Baker 1971_ [doi](https://doi.org/10.1016/s0021-9614%2871%2980068-x) | Table 2, p. 2, row 8; `ORC-JGMS3QYHGU.04cfd2` |  |
| CeC2 | [CeC2](https://data.orchid-project.org/compounds/CeC2.html) | -40.03 kJ/mol-atom ± 3.7 | 298.15 | experimental | -15.378 (mp-aaaaaeff) | -8.01 (oqmd-13373) | [1] Peng 2011; _cites Vidhya 2003_ [doi](https://doi.org/10.1016/s0022-3115%2803%2900071-0) | Table 2, p. 2, row 16; `ORC-UPE37JFFSG.27e28e` |  |
| CeC2 | [CeC2](https://data.orchid-project.org/compounds/CeC2.html) | -34.9 kJ/mol-atom | 298.15 | experimental | -15.378 (mp-aaaaaeff) | -8.01 (oqmd-13373) | [1] Peng 2011; _cites Faircloth 1968_ [doi](https://doi.org/10.1016/0022-1902%2868%2980476-2) | Table 2, p. 2, row 15; `ORC-JQOKSVUD7L` |  |
| CeC2 | [CeC2](https://data.orchid-project.org/compounds/CeC2.html) | -32.4 kJ/mol-atom ± 1.8 | 298.15 | experimental | -15.378 (mp-aaaaaeff) | -8.01 (oqmd-13373) | [1] Peng 2011; _cites Baker 1971_ [doi](https://doi.org/10.1016/s0021-9614%2871%2980068-x) | Table 2, p. 2, row 14; `ORC-G6NSZLCZ6G.8b7d6b` |  |
| CeC2 | [CeC2](https://data.orchid-project.org/compounds/CeC2.html) | -31.3 kJ/mol-atom | 298.15 | experimental | -15.378 (mp-aaaaaeff) | -8.01 (oqmd-13373) | [1] Peng 2011; _cites Pialoux 1988_ [doi](https://doi.org/10.1016/0022-5088%2888%2990046-x) | Table 2, p. 2, row 13; `ORC-VQHVGJKEGN` |  |
| CeC2 | [CeC2](https://data.orchid-project.org/compounds/CeC2.html) | -29.5 kJ/mol-atom ± 3.5 | 298.15 | experimental | -15.378 (mp-aaaaaeff) | -8.01 (oqmd-13373) | [1] Peng 2011; _cites Anderson 2011_ | Table 2, p. 2, row 12; `ORC-33HYQ2NTQM.39f3d1` |  |
| CeC2 | [CeC2](https://data.orchid-project.org/compounds/CeC2.html) | -27.2 kJ/mol-atom | 298.15 | experimental | -15.378 (mp-aaaaaeff) | -8.01 (oqmd-13373) | [1] Peng 2011; _cites Winchell 1967_ [doi](https://doi.org/10.1021/j100872a050) | Table 2, p. 2, row 10; `ORC-7ZU55J4DMS` |  |
| CeC2 | [CeC2](https://data.orchid-project.org/compounds/CeC2.html) | -25.4 kJ/mol-atom ± 1.4 | 298.15 | experimental | -15.378 (mp-aaaaaeff) | -8.01 (oqmd-13373) | [1] Peng 2011; _cites Meschel 1995_ [doi](https://doi.org/10.1016/0925-8388%2894%2906009-6) | Table 2, p. 2, row 11; `ORC-IJVD6G4UC3.004536` |  |
| CeC2 | [CeC2](https://data.orchid-project.org/compounds/CeC2.html) | -20.9 kJ/mol-atom ± 7 | 298.15 | experimental | -15.378 (mp-aaaaaeff) | -8.01 (oqmd-13373) | [1] Peng 2011; _cites Balducci 1969_ | Table 2, p. 2, row 9; `ORC-LYASWSGJGJ.1deb6c` |  |

## Other properties

### Crystal structure (5)

Table: Crystal structure, C–Ce system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 5.93 Å |  | β CeC2; _alloy: Ce 0.333333_ | experimental | [1] Peng 2011; _cites Winchell 1967_ [doi](https://doi.org/10.1021/j100872a050) | Table 1, p. 2, row 11; `ORC-UUJQ7CFIHH.6ee29d` |  |
| Lattice a | 8.44 Å | 298.15 | Ce2C3; _alloy: Ce 0.4_ | experimental | [1] Peng 2011; _cites Atoji 1961_ | Table 1, p. 2, row 9; `ORC-MWHABIRH56` |  |
| Lattice a | 3.88 Å | 298.15 | α CeC2; _alloy: Ce 0.333333_ | experimental | [1] Peng 2011; _cites Jones 1986_ [doi](https://doi.org/10.1016/0022-4596%2886%2990228-8) | Table 1, p. 2, row 10; `ORC-MHPKDH47I6.1e3f3c` |  |
| Lattice c | 5.2 Å |  | β CeC2; _alloy: Ce 0.333333_ | experimental | [1] Peng 2011; _cites Winchell 1967_ [doi](https://doi.org/10.1021/j100872a050) | Table 1, p. 2, row 11; `ORC-UUJQ7CFIHH.792bda` |  |
| Lattice c | 6.48 Å | 298.15 | α CeC2; _alloy: Ce 0.333333_ | experimental | [1] Peng 2011; _cites Jones 1986_ [doi](https://doi.org/10.1016/0022-4596%2886%2990228-8) | Table 1, p. 2, row 10; `ORC-MHPKDH47I6.33eed6` |  |

## Sources

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

1. Yingbiao Peng, Yong Du, Lijun Zhang, Chunsheng Sha, Shuhong Liu, Feng Zheng et al., Thermodynamic modeling of the C–RE (RE=La, Ce and Pr) systems, Calphad 35, 533-541 (2011). [doi:10.1016/j.calphad.2011.09.002](https://doi.org/10.1016/j.calphad.2011.09.002)

## 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-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD) (version 2026.10), Zenodo (2026). https://doi.org/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). 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); 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.

```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_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}
}
```

---

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/).