# AlP: enthalpy of formation

> Enthalpy of formation of AlP: 28 literature value(s) with sources, pages and quotes and DFT values (Materials Project / OQMD), from ORCHID.

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

28 accepted literature formation-enthalpy value(s) (experimental 12, model 15, unspecified 1); experimental median -32.135 kJ/mol-atom (n = 4); Materials Project -58.834 kJ/mol-atom (mp-aaaaachq); OQMD -71.088 kJ/mol-atom (oqmd-4641).

Systems: [Al–P](https://data.orchid-project.org/systems/AL-P.html)

## Literature values

Table: Enthalpy of formation of AlP reported in the literature (28)

| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---:|---|---:|---|---|---|---|---|---|
| -90.2 kJ/mol (basis unstated) | AlP | 298.15 | experimental |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [1] Miettinen 2015; _cites Peviak 1974_ | Table 4, p. 6, row 8; `ORC-C2MP6ECWTH` |  |
| -90.2 per mol-atom ± 4 | AlP | 298.15 | experimental | Measured | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013; _cites Peviak 1974_ | Table 3, p. 3, row 4; `ORC-SKLXQ5SK5Y` |  |
| -82.6 per mol-atom ± 1 | AlP | 298.15 | experimental | Measured | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013; _cites Kischio 1965_ [doi](https://doi.org/10.1016/0022-1902%2865%2980287-1) | Table 3, p. 3, row 2; `ORC-S4MMRQUPVI` |  |
| -82.6 kJ/mol (basis unstated) | AlP | 298.15 | experimental |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [1] Miettinen 2015; _cites Kischio 1965_ [doi](https://doi.org/10.1016/0022-1902%2865%2980287-1) | Table 4, p. 6, row 6; `ORC-Y4GCFEKXA5` |  |
| -81.6 per mol-atom ± 1 | AlP | 298.15 | experimental | Measured | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013; _cites Martosudirdjo 1974_ [doi](https://doi.org/10.1016/0040-6031%2874%2985019-7) | Table 3, p. 3, row 3; `ORC-HQMUO6H5DT` |  |
| -81.6 kJ/mol (basis unstated) | AlP | 298.15 | experimental |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [1] Miettinen 2015; _cites Martosudirdjo 1974_ [doi](https://doi.org/10.1016/0040-6031%2874%2985019-7) | Table 4, p. 6, row 7; `ORC-SJ7BY3I35U` |  |
| -69.4 per mol-atom ± 4 | AlP | 298.15 | experimental | Measured | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013; _cites Wang 1963_ [doi](https://doi.org/10.1016/0022-1902%2863%2980071-8) | Table 3, p. 3, row 1; `ORC-IVQQNZDCYK` |  |
| -69.4 kJ/mol (basis unstated) | AlP | 298.15 | experimental |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [1] Miettinen 2015; _cites Wang 1963_ [doi](https://doi.org/10.1016/0022-1902%2863%2980071-8) | Table 4, p. 6, row 5; `ORC-YACG6AQ43C` |  |
| -41.3 kJ/mol-atom ± 0.55 | AlP | 298.15 | experimental |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [3] Tu 2009; _cites Kischio 1965_ [doi](https://doi.org/10.1016/0022-1902%2865%2980287-1) | Table 3, p. 4, row 2; `ORC-A3TK3RSOWQ` |  |
| -34.77 kJ/mol-atom ± 2.3 | AlP | 298.15 | experimental |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [3] Tu 2009; _cites Wang 1963_ [doi](https://doi.org/10.1016/0022-1902%2863%2980071-8) | Table 3, p. 4, row 1; `ORC-AMM5CYBKX7` |  |
| -29.5 kJ/mol-atom ± 3.35 | AlP | 298.15 | experimental |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [3] Tu 2009; _cites G 1968_ | Table 3, p. 4, row 3; `ORC-VSKJCGX4YM` |  |
| -28.8 kJ/mol-atom ± 8.85 | AlP | 298.15 | experimental |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [3] Tu 2009; _cites Martosudirdjo 1974_ [doi](https://doi.org/10.1016/0040-6031%2874%2985019-7) | Table 3, p. 4, row 4; `ORC-BVWDFFOBII` |  |
| -164.5 kJ/mol (basis unstated) | AlP | 298.15 | model |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [4] Onderka 2002; _cites Kaufman 1981_ | Table AI, p. 19, row 8; `ORC-RWG4CSVSSQ` |  |
| -148.6 kJ/mol (basis unstated) | AlP | 298.15 | model |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [4] Onderka 2002; _cites Ansara 1994_ | Table AI, p. 19, row 6; `ORC-5256XVKBSM.cd4a24` |  |
| -91.5 per mol-atom | AlP | 298.15 | model | Calculated | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013; _cites Kaufman 1981_ [doi](https://doi.org/10.1016/0364-5916%2881%2990020-1) | Table 3, p. 3, row 5; `ORC-6W2764KCGG.3beb49` |  |
| -82.2 per mol-atom | AlP | 298.15 | model | Reviewed | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013; _cites Barin 1977_ | Table 3, p. 3, row 12; `ORC-IFG25P7NFF.6d560f` |  |
| -82.2 per mol-atom | AlP | 298.15 | model | Calculated | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013; _cites Wu 2012_ [doi](https://doi.org/10.1016/j.calphad.2012.03.005) | Table 3, p. 3, row 9; `ORC-T4A3VZGQC2.8fce70` |  |
| -81.8 kJ/mol (basis unstated) | AlP | 298.15 | model |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [1] Miettinen 2015 | Table 4, p. 6, row 4; `ORC-GX4RQ2FGJ3` |  |
| -81.6 per mol-atom | AlP | 298.15 | model | Calphad | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013 | Table 3, p. 3, row 14; `ORC-QPXL563LZK.7eed37` |  |
| -81.6 kJ/mol (basis unstated) | AlP | 298.15 | model |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [1] Miettinen 2015; _cites Liang 2013_ [doi](https://doi.org/10.1016/j.calphad.2013.07.001) | Table 4, p. 6, row 3; `ORC-WOS5MKXV6V` |  |
| -80.4 per mol-atom | AlP | 298.15 | model | Calculated | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013; _cites McAlister 2013_ | Table 3, p. 3, row 6; `ORC-EODCGTI733.17bd76` |  |
| -74.3 per mol-atom | AlP | 298.15 | model | Calculated | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013; _cites Ansara 1994_ [doi](https://doi.org/10.1016/0364-5916%2894%2990027-2) | Table 3, p. 3, row 7; `ORC-K2UELGMSEL.b80bd7` |  |
| -74.3 kJ/mol (basis unstated) | AlP | 298.15 | model |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [1] Miettinen 2015; _cites Ansara 1994_ [doi](https://doi.org/10.1016/0364-5916%2894%2990027-2) | Table 4, p. 6, row 1; `ORC-VD2LVU46DJ` |  |
| -67.7 per mol-atom ± 6.7 | AlP | 298.15 | model | Derived | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013; _cites De 1968_ | Table 3, p. 3, row 13; `ORC-W2YWDUUAFL` |  |
| -51 kJ/mol (basis unstated) | AlP | 298.15 | model |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [1] Miettinen 2015; _cites Tu 2009_ [doi](https://doi.org/10.1016/j.calphad.2009.10.003) | Table 4, p. 6, row 2; `ORC-7JEA2OET6I` |  |
| -51 per mol-atom | AlP | 298.15 | model | Calculated | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [2] Liang 2013; _cites Tu 2009_ [doi](https://doi.org/10.1016/j.calphad.2009.10.003) | Table 3, p. 3, row 8; `ORC-7TTMWV5LU3.62f04c` |  |
| -25.5 kJ/mol-atom | AlP | 298.15 | model |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [3] Tu 2009 | Table 3, p. 4, row 5; `ORC-HN6OKJZHTO` |  |
| -166.5 kJ/mol (basis unstated) | AlP | 298.15 | unspecified |  | [Al–P](https://data.orchid-project.org/systems/AL-P.html) | [4] Onderka 2002; _cites Wagman 1968_ | Table AI, p. 19, row 7; `ORC-3P2UCAWWEI` |  |

### 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 AlP

| Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective |
|---:|---|---:|---:|---|---:|---:|---:|---:|
| -90.2 | kJ/mol (basis unstated) |  | 0.05 | 7 (unknown, calibrated) |  |  |  | 7 |
| -90.2 | per mol-atom | 4 | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | 4 |
| -82.6 | per mol-atom | 1 | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | 1 |
| -82.6 | kJ/mol (basis unstated) |  | 0.05 | 7 (unknown, calibrated) |  |  |  | 7 |
| -81.6 | per mol-atom | 1 | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | 1 |
| -81.6 | kJ/mol (basis unstated) |  | 0.05 | 7 (unknown, calibrated) |  |  |  | 7 |
| -69.4 | per mol-atom | 4 | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | 4 |
| -69.4 | kJ/mol (basis unstated) |  | 0.05 | 7 (unknown, calibrated) |  |  |  | 7 |
| -41.3 | kJ/mol-atom | 0.55 | 2.500e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -34.77 | kJ/mol-atom | 2.3 | 2.500e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -29.5 | kJ/mol-atom | 3.35 | 2.500e-4 | 3.5 (unknown, calibrated) |  |  |  | 3.5 |
| -28.8 | kJ/mol-atom | 8.85 | 2.500e-4 | 3.5 (unknown, calibrated) |  |  |  | 8.85 |
| -164.5 | kJ/mol (basis unstated) |  | 0.05 | 7.8 (model_calculated, calibrated) |  |  |  | 7.8 |
| -148.6 | kJ/mol (basis unstated) |  | 0.05 | 7.8 (model_calculated, calibrated) |  |  |  | 7.8 |
| -91.5 | per mol-atom |  | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | unit 'per mol-atom' not convertible to kJ/mol-atom |
| -82.2 | per mol-atom |  | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | unit 'per mol-atom' not convertible to kJ/mol-atom |
| -82.2 | per mol-atom |  | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | unit 'per mol-atom' not convertible to kJ/mol-atom |
| -81.8 | kJ/mol (basis unstated) |  | 0.05 | 7.8 (model_calculated, calibrated) |  |  |  | 7.8 |
| -81.6 | per mol-atom |  | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | unit 'per mol-atom' not convertible to kJ/mol-atom |
| -81.6 | kJ/mol (basis unstated) |  | 0.05 | 7.8 (model_calculated, calibrated) |  |  |  | 7.8 |
| -80.4 | per mol-atom |  | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | unit 'per mol-atom' not convertible to kJ/mol-atom |
| -74.3 | per mol-atom |  | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | unit 'per mol-atom' not convertible to kJ/mol-atom |
| -74.3 | kJ/mol (basis unstated) |  | 0.05 | 7.8 (model_calculated, calibrated) |  |  |  | 7.8 |
| -67.7 | per mol-atom | 6.7 | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | 6.7 |
| -51 | kJ/mol (basis unstated) |  | 0.05 | 7.8 (model_calculated, calibrated) |  |  |  | 7.8 |
| -51 | per mol-atom |  | 0.5 | unit 'per mol-atom' not convertible to kJ/mol-atom |  |  |  | unit 'per mol-atom' not convertible to kJ/mol-atom |
| -25.5 | kJ/mol-atom |  | 2.500e-4 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -166.5 | kJ/mol (basis unstated) |  | 0.05 | 7 (unknown, calibrated) |  |  |  | 7 |

## 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 AlP

| Source | Entry | kJ/mol-atom | eV/atom | Space group | E above hull (kJ/mol-atom) | E above hull (eV/atom) | Theoretical |
|---|---|---:|---:|---|---:|---:|---|
| Materials Project | mp-aaaaachq | -58.834 | -0.609772 | F-43m | 0 | 0 | no |
| OQMD | oqmd-4641 | -71.088 | -0.736775 | F-43m | 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. Jyrki Miettinen, Seppo Louhenkilpi, Gueorgui Vassilev, Thermodynamic Description of Ternary Fe-X-P Systems. Part 9: Fe-Al-P, J. Phase Equilib. Diffus. 36, 317-326 (2015). [doi:10.1007/s11669-015-0383-5](https://doi.org/10.1007/s11669-015-0383-5)
2. Song-Mao Liang, Rainer Schmid-Fetzer, Thermodynamic assessment of the Al–P system based on original experimental data, Calphad 42, 76-85 (2013). [doi:10.1016/j.calphad.2013.07.001](https://doi.org/10.1016/j.calphad.2013.07.001)
3. Hao Tu, Fucheng Yin, Xuping Su, Ya Liu, Xinming Wang, Experimental investigation and thermodynamic modeling of the Al–P–Zn ternary system, Calphad 33, 755-760 (2009). [doi:10.1016/j.calphad.2009.10.003](https://doi.org/10.1016/j.calphad.2009.10.003)
4. B. Onderka, J. Unland, R. Schmid-Fetzer, Thermodynamics and phase stability in the In–N system, J. Mater. Res. 17, 3065-3083 (2002). [doi:10.1557/jmr.2002.0445](https://doi.org/10.1557/jmr.2002.0445)

## 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/).