# Cu8Zr3: enthalpy of formation

> Enthalpy of formation of Cu8Zr3: 7 literature value(s) with sources, pages and quotes and DFT values (Materials Project / OQMD), from ORCHID.

HTML: https://data.orchid-project.org/compounds/Cu8Zr3.html · Markdown: https://data.orchid-project.org/compounds/Cu8Zr3.md

7 accepted literature formation-enthalpy value(s) (experimental 2, model 4, DFT 1); experimental median -14.091 kJ/mol-atom (n = 2); Materials Project -16.12 kJ/mol-atom (mp-aaacqazd); OQMD -15.764 kJ/mol-atom (oqmd-2052365).

Systems: [Cu–Zr](https://data.orchid-project.org/systems/CU-ZR.html)

## Literature values

Table: Enthalpy of formation of Cu8Zr3 reported in the literature (7)

| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---:|---|---:|---|---|---|---|---|---|
| -16.2 kJ/mol-atom | Cu8Zr3 | 298.15 | experimental |  | [Cu–Zr](https://data.orchid-project.org/systems/CU-ZR.html) | [1] Turchanin 2008; _cites Yamaguchi 2008_ [doi](https://doi.org/10.1016/j.jallcom.2007.01.173) | Table 3, p. 10, row 10; `ORC-BAK334PAP7` |  |
| -11.982 kJ/mol-atom ± 0.083 | Cu8Zr3 | 1123 | experimental |  | [Cu–Zr](https://data.orchid-project.org/systems/CU-ZR.html) | [1] Turchanin 2008; _cites Zaitsev 2003_ [doi](https://doi.org/10.1023/a:1022372503921) | Table 3, p. 10, row 9; `ORC-UGI6UJCAPF.4d8255` |  |
| -15.816 kJ/mol-atom | Cu8Zr3 |  | model |  | [Cu–Zr](https://data.orchid-project.org/systems/CU-ZR.html) | [2] Zeng 1994; _cites Saunders 1985_ [doi](https://doi.org/10.1016/0364-5916%2885%2990001-x) | Table 1, p. 1, row 7; `ORC-DAASBEB5UU` |  |
| -14.788 kJ/mol-atom | Cu8Zr3 | 1123 | model |  | [Cu–Zr](https://data.orchid-project.org/systems/CU-ZR.html) | [1] Turchanin 2008 | Table 3, p. 10, row 11; `ORC-Q6PF2OXFB4.b799a0` |  |
| -13.4603 kJ/mol-atom | Cu8Zr3 |  | model |  | [Cu–Zr](https://data.orchid-project.org/systems/CU-ZR.html) | [2] Zeng 1994 | Table 1, p. 1, row 9; `ORC-WGO2E6UO7R` |  |
| -3.24593 kJ/mol-atom | Cu8Zr3 |  | model |  | [Cu–Zr](https://data.orchid-project.org/systems/CU-ZR.html) | [2] Zeng 1994; _cites Luoma 1991_ | Table 1, p. 1, row 8; `ORC-2G7QGK43YE` |  |
| -18.21 kJ/mol-atom | Cu8Zr3-δ | 0 | DFT | USPP-GGA | [Cu–Zr](https://data.orchid-project.org/systems/CU-ZR.html) | [3] Zhou 2010; _cites Ghosh 2007_ | Table 2, p. 3, row 10; `ORC-OMXVCGIYSU.54bd14` |  |

### 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 Cu8Zr3

| Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective |
|---:|---|---:|---:|---|---:|---:|---:|---:|
| -16.2 | kJ/mol-atom |  | 5.000e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -11.982 | kJ/mol-atom | 0.083 | 4.563e-4 | 3.5 (unknown, calibrated) |  |  | 0.1147 | 3.502 |
| -15.816 | kJ/mol-atom |  | 5.000e-4 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -14.788 | kJ/mol-atom |  | 5.000e-4 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -13.4603 | kJ/mol-atom |  | 5.000e-6 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -3.24593 | kJ/mol-atom |  | 5.000e-6 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -18.21 | kJ/mol-atom |  | 0.005 | 8.395 (dft, calibrated) |  |  |  | 8.395 |

## DFT formation energies

Lowest-energy entries at this composition. Materials Project and OQMD use different energy references and are never averaged. 1 eV/atom = 96.485 kJ/mol-atom.

Table: DFT formation energy of Cu8Zr3

| Source | Entry | kJ/mol-atom | eV/atom | Space group | E above hull (kJ/mol-atom) | E above hull (eV/atom) | Theoretical |
|---|---|---:|---:|---|---:|---:|---|
| Materials Project | mp-aaacqazd | -16.12 | -0.167076 | Pnma | 0 | 0 | no |
| OQMD | oqmd-2052365 | -15.764 | -0.163388 | Pnma | 0 | 0 | yes |

DFT sources: A. Jain et al., Commentary: The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002. [doi:10.1063/1.4812323](https://doi.org/10.1063/1.4812323) (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501-1509; S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010. [doi:10.1007/s11837-013-0755-4](https://doi.org/10.1007/s11837-013-0755-4) (CC BY 4.0); 

## Sources

1. M. A. Turchanin, P. G. Agraval, A. R. Abdulov, Thermodynamic assessment of the Cu-Ti-Zr system. II. Cu-Zr and Ti-Zr systems, Powder Metall Met Ceram 47, 428-446 (2008). [doi:10.1007/s11106-008-9039-x](https://doi.org/10.1007/s11106-008-9039-x)
2. K. J. Zeng, M. Hämäläinen, H. L. Lukas, A new thermodynamic description of the Cu-Zr system, JPE 15, 577-586 (1994). [doi:10.1007/bf02647618](https://doi.org/10.1007/bf02647618)
3. S.H. Zhou, R.E. Napolitano, Phase stability for the Cu–Zr system: First-principles, experiments and solution-based modeling, Acta Materialia 58, 2186-2196 (2010). [doi:10.1016/j.actamat.2009.12.004](https://doi.org/10.1016/j.actamat.2009.12.004)

## 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/).