# U0.345C0.655: enthalpy of formation

> Enthalpy of formation of U0.345C0.655: 9 literature value(s) with sources, pages and quotes, from ORCHID.

HTML: https://data.orchid-project.org/compounds/U0.345C0.655.html · Markdown: https://data.orchid-project.org/compounds/U0.345C0.655.md

9 accepted literature formation-enthalpy value(s) (experimental 9); experimental median -30.442 kJ/mol-atom (n = 9).

Systems: [C–U](https://data.orchid-project.org/systems/C-U.html)

## Literature values

Table: Enthalpy of formation of U0.345C0.655 reported in the literature (9)

| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---:|---|---:|---|---|---|---|---|---|
| -31.798 kJ/mol-atom | C0.655U0.345 | 298.15 | experimental |  | [C–U](https://data.orchid-project.org/systems/C-U.html) | [1] Chevalier 2001; _cites Benesovsky 1961_ | Table 21, p. 17, row 11; `ORC-MS3CBROHJH.4fbc53` |  |
| -31.38 kJ/mol-atom | C0.655U0.345 | 298.15 | experimental |  | [C–U](https://data.orchid-project.org/systems/C-U.html) | [1] Chevalier 2001; _cites Leitnaker 1962_ [doi](https://doi.org/10.1063/1.1732762) | Table 21, p. 17, row 13; `ORC-GHYX64I4DB.ba7abb` |  |
| -31.38 kJ/mol-atom | C0.655U0.345 | 298.15 | experimental |  | [C–U](https://data.orchid-project.org/systems/C-U.html) | [1] Chevalier 2001; _cites Storms 1965_ | Table 21, p. 17, row 18; `ORC-N5YTMMR3NQ.a08881` |  |
| -30.543 kJ/mol-atom ± 2.929 | C0.655U0.345 | 298.15 | experimental |  | [C–U](https://data.orchid-project.org/systems/C-U.html) | [1] Chevalier 2001; _cites Hultgren 1973_ | Table 21, p. 17, row 25; `ORC-IQKO6FH2Q3.7fe11f` |  |
| -30.442 kJ/mol-atom ± 2.02 | C0.655U0.345 | 298.15 | experimental |  | [C–U](https://data.orchid-project.org/systems/C-U.html) | [1] Chevalier 2001; _cites Huber 1963_ [doi](https://doi.org/10.1021/j100802a510) | Table 21, p. 17, row 22; `ORC-LV4SGXSJXS.c02e76` |  |
| -28.422 kJ/mol-atom ± 4.404 | C0.655U0.345 | 298.15 | experimental |  | [C–U](https://data.orchid-project.org/systems/C-U.html) | [1] Chevalier 2001; _cites Huber 1963_ [doi](https://doi.org/10.1021/j100802a510) | Table 21, p. 17, row 20; `ORC-DLPIODCAG2.125005` |  |
| -27.614 kJ/mol-atom | C0.655U0.345 | 298.15 | experimental |  | [C–U](https://data.orchid-project.org/systems/C-U.html) | [1] Chevalier 2001; _cites Lonsdale 1962_ | Table 21, p. 17, row 16; `ORC-X6FQXSGJHQ.3a6d75` |  |
| -26.835 kJ/mol-atom ± 2.885 | C0.655U0.345 | 298.15 | experimental |  | [C–U](https://data.orchid-project.org/systems/C-U.html) | [1] Chevalier 2001; _cites Huber 1963_ [doi](https://doi.org/10.1021/j100802a510) | Table 21, p. 17, row 21; `ORC-35WTM76WD5.0b8b03` |  |
| -18.41 kJ/mol-atom | C0.655U0.345 | 298.15 | experimental |  | [C–U](https://data.orchid-project.org/systems/C-U.html) | [1] Chevalier 2001; _cites Alcock 1962_ | Table 21, p. 17, row 15; `ORC-23ZIGYN2CV.7c099c` |  |

### Uncertainty budget

Components kept separate, in the value's unit (literature [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md), [UNCERTAINTY_CALIBRATION.md](https://data.orchid-project.org/literature/UNCERTAINTY_CALIBRATION.md)): effective = max(sqrt(max(printed, reading, method)^2 + composition^2 + conversion^2), scatter). The method floor is the robust between-study scatter of the method class in ORCHID (calibrated) or a documented prior; printed values and printed uncertainties are unchanged.

Table: Uncertainty budget of the literature values of U0.345C0.655

| Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective |
|---:|---|---:|---:|---|---:|---:|---:|---:|
| -31.798 | kJ/mol-atom |  | 5.000e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -31.38 | kJ/mol-atom |  | 5.000e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -31.38 | kJ/mol-atom |  | 5.000e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -30.543 | kJ/mol-atom | 2.929 | 5.000e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -30.442 | kJ/mol-atom | 2.02 | 5.000e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -28.422 | kJ/mol-atom | 4.404 | 5.000e-4 | 3.5 (unknown, calibrated) |  |  |  | 4.404 |
| -27.614 | kJ/mol-atom |  | 5.000e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -26.835 | kJ/mol-atom | 2.885 | 5.000e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -18.41 | kJ/mol-atom |  | 5.000e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |

## Sources

1. P.Y Chevalier, E Fischer, Thermodynamic modelling of the C–U and B–U binary systems, Journal of Nuclear Materials 288, 100-129 (2001). [doi:10.1016/s0022-3115(00)00713-3](https://doi.org/10.1016/s0022-3115%2800%2900713-3)

## 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-Parity: DFT-vs-experiment formation-enthalpy benchmark (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23735943
- 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); G. Kim, S. V. Meschel, P. Nash, W. Chen, Experimental formation enthalpies for intermetallic phases and other inorganic compounds, Scientific Data 4 (2017) 170162, https://doi.org/10.1038/sdata.2017.162; 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_dft_benchmark_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Parity: DFT-vs-experiment formation-enthalpy benchmark}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735943},
  url       = {https://doi.org/10.5281/zenodo.23735943},
  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/).
