# ZrO2: enthalpy of formation

> Enthalpy of formation of ZrO2: 16 literature value(s) with sources, pages and quotes and DFT values (Materials Project / OQMD), from ORCHID.

HTML: https://data.orchid-project.org/compounds/ZrO2.html · Markdown: https://data.orchid-project.org/compounds/ZrO2.md

16 accepted literature formation-enthalpy value(s) (experimental 6, model 9, unspecified 1); experimental median -366 kJ/mol-atom (n = 1); Materials Project -367.957 kJ/mol-atom (mp-aaaaaefy); OQMD -350.528 kJ/mol-atom (oqmd-3278).

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

## Literature values

Table: Enthalpy of formation of ZrO2 reported in the literature (16)

| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---:|---|---:|---|---|---|---|---|---|
| -1100.92 kJ/mol (basis unstated) | monoclinic ZrO2 | 298.15 | experimental |  | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [1] Wang 2004; _cites Huber 1964_ [doi](https://doi.org/10.1021/j100792a052) | Table 3, p. 6, row 3; `ORC-O2N4Y6PU3L` |  |
| -1100.8 kJ/mol (basis unstated) | ZrO2 | 298.15 | experimental | Combustion calorimetry | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [2] CHEN 2004; _cites Huber 1964_ | Table 2, p. 3, row 2; `ORC-HYAEJ3WDYQ` |  |
| -1100.6 kJ/mol (basis unstated) | ZrO2 | 298.15 | experimental | Combustion calorimetry | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [2] CHEN 2004; _cites Kornilov 1967_ | Table 2, p. 3, row 3; `ORC-SNG6VNMBGO` |  |
| -1100.56 kJ/mol (basis unstated) | monoclinic ZrO2 | 298.15 | experimental |  | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [1] Wang 2004; _cites Kornilov 1967_ | Table 3, p. 6, row 4; `ORC-BCTQCRDUEV` |  |
| -1094.1 kJ/mol (basis unstated) | ZrO2 | 298.15 | experimental | Combustion calorimetry | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [2] CHEN 2004; _cites Humphrey 1954_ | Table 2, p. 3, row 1; `ORC-4I4UZK2EY5` |  |
| -366 kJ/mol-atom | ZrO2 | 298.15 | experimental |  | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [3] Arroyave 2002 | Table 2, p. 17, row 2; `ORC-T64EA4SVSN` |  |
| -1101 kJ/mol (basis unstated) | ZrO2 | 298.15 | model | Assessed | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [2] CHEN 2004; _cites Liang 2001_ | Table 2, p. 3, row 6; `ORC-VKOW7JMG67` |  |
| -1100.97 kJ/mol (basis unstated) | monoclinic ZrO2 | 298.15 | model |  | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [1] Wang 2004; _cites Liang 2001_ | Table 3, p. 6, row 8; `ORC-F6NCSYDKXL.fbb5b1` |  |
| -1100.7 kJ/mol (basis unstated) | ZrO2 | 298.15 | model | Assessed | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [2] CHEN 2004 | Table 2, p. 3, row 7; `ORC-TVSCV5S6Q3` |  |
| -1100.69 kJ/mol (basis unstated) | monoclinic ZrO2 | 298.15 | model |  | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [1] Wang 2004; _cites Chen 2004_ | Table 3, p. 6, row 10; `ORC-E5CPA7HYOF.222153` |  |
| -1100.6 kJ/mol (basis unstated) | ZrO2 | 298.15 | model | Assessed | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [2] CHEN 2004; _cites Ackermann 1975_ | Table 2, p. 3, row 4; `ORC-UIQ7XPTRO2` |  |
| -1100.57 kJ/mol (basis unstated) | monoclinic ZrO2 | 298.15 | model |  | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [1] Wang 2004; _cites Du 1992_ [doi](https://doi.org/10.1111/j.1151-2916.1992.tb04384.x) | Table 3, p. 6, row 7; `ORC-WVWMHM2MNK.d74e97` |  |
| -1100.31 kJ/mol (basis unstated) | monoclinic ZrO2 | 298.15 | model |  | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [1] Wang 2004; _cites Arroyave 2002_ [doi](https://doi.org/10.1016/s0364-5916%2802%2900027-5) | Table 3, p. 6, row 9; `ORC-GJPSMMKMUH.3afd39` |  |
| -1097.46 kJ/mol (basis unstated) | ZrO2 | 298.15 | model | Assessed | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [2] CHEN 2004; _cites Chase 1985_ | Table 2, p. 3, row 5; `ORC-KUB2D3A4PC` |  |
| -573 kJ/mol-atom | ZrO2 |  | model | Electronegativities | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [3] Arroyave 2002 | Table 2, p. 17, row 1; `ORC-UT4GG4A3ZU` |  |
| -1100.57 kJ/mol (basis unstated) | monoclinic ZrO2 | 298.15 | unspecified |  | [O–Zr](https://data.orchid-project.org/systems/O-ZR.html) | [1] Wang 2004; _cites Dinsdale 2003_ | Table 3, p. 6, row 11; `ORC-XPXHLUS742.b1fdcc` |  |

### 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 ZrO2

| Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective |
|---:|---|---:|---:|---|---:|---:|---:|---:|
| -1100.92 | kJ/mol (basis unstated) |  | 5.000e-4 | 10.5 (unknown, calibrated) |  |  |  | 10.5 |
| -1100.8 | kJ/mol (basis unstated) |  | 0.05 | 3 (combustion_calorimetry, cleaned_below_threshold) |  |  |  | 3 |
| -1100.6 | kJ/mol (basis unstated) |  | 0.05 | 3 (combustion_calorimetry, cleaned_below_threshold) |  |  |  | 3 |
| -1100.56 | kJ/mol (basis unstated) |  | 5.000e-4 | 10.5 (unknown, calibrated) |  |  |  | 10.5 |
| -1094.1 | kJ/mol (basis unstated) |  | 0.05 | 3 (combustion_calorimetry, cleaned_below_threshold) |  |  |  | 3 |
| -366 | kJ/mol-atom |  | 5.000e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -1101 | kJ/mol (basis unstated) |  | 0.5 | 11.7 (model_calculated, calibrated) |  |  |  | 11.7 |
| -1100.97 | kJ/mol (basis unstated) |  | 5.000e-4 | 11.7 (model_calculated, calibrated) |  |  |  | 11.7 |
| -1100.7 | kJ/mol (basis unstated) |  | 0.05 | 11.7 (model_calculated, calibrated) |  |  |  | 11.7 |
| -1100.69 | kJ/mol (basis unstated) |  | 5.000e-5 | 11.7 (model_calculated, calibrated) |  |  |  | 11.7 |
| -1100.6 | kJ/mol (basis unstated) |  | 0.05 | 11.7 (model_calculated, calibrated) |  |  |  | 11.7 |
| -1100.57 | kJ/mol (basis unstated) |  | 5.000e-5 | 11.7 (model_calculated, calibrated) |  |  |  | 11.7 |
| -1100.31 | kJ/mol (basis unstated) |  | 5.000e-5 | 11.7 (model_calculated, calibrated) |  |  |  | 11.7 |
| -1097.46 | kJ/mol (basis unstated) |  | 5.000e-4 | 11.7 (model_calculated, calibrated) |  |  |  | 11.7 |
| -573 | kJ/mol-atom |  | 5.000e-4 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -1100.57 | kJ/mol (basis unstated) |  | 5.000e-5 | 10.5 (unknown, calibrated) |  |  |  | 10.5 |

## 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 ZrO2

| Source | Entry | kJ/mol-atom | eV/atom | Space group | E above hull (kJ/mol-atom) | E above hull (eV/atom) | Theoretical |
|---|---|---:|---:|---|---:|---:|---|
| Materials Project | mp-aaaaaefy | -367.957 | -3.81362 | P2_1/c | 0 | 0 | no |
| OQMD | oqmd-3278 | -350.528 | -3.63298 | P21/c | 0 | 0 | no |

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. Chong Wang, Matvei Zinkevich, Fritz Aldinger, On the thermodynamic modeling of the Zr–O system, Calphad 28, 281-292 (2004). [doi:10.1016/j.calphad.2004.09.002](https://doi.org/10.1016/j.calphad.2004.09.002)
2. M CHEN, B HALLSTEDT, L GAUCKLER, Thermodynamic modeling of the ZrO2–YO1.5 system, Solid State Ionics 170, 255-274 (2004). [doi:10.1016/j.ssi.2004.02.017](https://doi.org/10.1016/j.ssi.2004.02.017)
3. Raymundo Arroyave, Larry Kaufman, Thomas W. Eagar, Thermodynamic modeling of the ZrO system, Calphad 26, 95-118 (2002). [doi:10.1016/s0364-5916(02)00027-5](https://doi.org/10.1016/s0364-5916%2802%2900027-5)

## 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/).