# Fe2Gd: enthalpy of formation > Enthalpy of formation of Fe2Gd: 14 literature value(s) with sources, pages and quotes and DFT values (Materials Project / OQMD), from ORCHID. HTML: https://data.orchid-project.org/compounds/Fe2Gd.html · Markdown: https://data.orchid-project.org/compounds/Fe2Gd.md 14 accepted literature formation-enthalpy value(s) (experimental 6, model 8); experimental median -7.55 kJ/mol-atom (n = 4); Materials Project 1.566 kJ/mol-atom (mp-aaaabdsr); OQMD -3.181 kJ/mol-atom (oqmd-18836). Systems: [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) ## Literature values Table: Enthalpy of formation of Fe2Gd reported in the literature (14) | Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote | |---:|---|---:|---|---|---|---|---|---| | -11.6 kJ/mol-atom ± 2 | Fe2Gd | 298.15 | experimental | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002; _cites Colinet 1987_ | Table 12, p. 13, row 9; `ORC-FGKIBVFKMX.551bc0` | | | -11.6 per mol-atom ± 2 | Fe2Gd | 298.15 | experimental | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002; _cites Colinet 1987_ | Table 12, p. 13, row 9; `ORC-FGKIBVFKMX.ce0b6f` | | | -11.6 kJ/mol-atom ± 2 | Fe2Gd | 298.15 | experimental | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [2] Zinkevich 2000; _cites Colinet 1987_ [doi](https://doi.org/10.1007/bf02646931) | Table 2, p. 3, row 2; `ORC-XVCLD777MT` | | | -3.5 kJ/mol-atom ± 1.5 | Fe2Gd | 1078 | experimental | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002; _cites Deodhar 1975_ | Table 12, p. 13, row 12; `ORC-HMWXYNWIGB.6907f1` | | | -3.5 per mol-atom ± 1.5 | Fe2Gd | 1078 | experimental | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002; _cites Deodhar 1975_ | Table 12, p. 13, row 12; `ORC-HMWXYNWIGB.dda405` | | | -3.5 kJ/mol-atom ± 1.5 | Fe2Gd | 1078 | experimental | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [2] Zinkevich 2000; _cites Deodhar 1975_ | Table 2, p. 3, row 1; `ORC-RPGFJXHR3N` | | | -6.81 kJ/mol-atom | Fe2Gd | 1078 | model | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002 | Table 12, p. 13, row 14; `ORC-HXPBIXMIXD.3ba26f` | | | -6.81 per mol-atom | Fe2Gd | 1078 | model | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002 | Table 12, p. 13, row 14; `ORC-HXPBIXMIXD.8deb2a` | | | -5.94 per mol-atom | Fe2Gd | 298.15 | model | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002 | Table 12, p. 13, row 11; `ORC-GXB5PU32U5.707e28` | | | -5.94 kJ/mol-atom | Fe2Gd | 298.15 | model | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002 | Table 12, p. 13, row 11; `ORC-GXB5PU32U5.b8ac0f` | | | -4.59 kJ/mol-atom | Fe2Gd | 298.15 | model | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002; _cites Zinkevich 2000_ | Table 12, p. 13, row 10; `ORC-DWSOOBGST7.2379bf` | | | -4.59 per mol-atom | Fe2Gd | 298.15 | model | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002; _cites Zinkevich 2000_ | Table 12, p. 13, row 10; `ORC-DWSOOBGST7.2e5ba1` | | | -4.38 kJ/mol-atom | Fe2Gd | 1078 | model | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002; _cites Zinkevich 2000_ | Table 12, p. 13, row 13; `ORC-HN34UL6CGG.36704a` | | | -4.38 per mol-atom | Fe2Gd | 1078 | model | | [Fe–Gd](https://data.orchid-project.org/systems/FE-GD.html) | [1] Zinkevich 2002; _cites Zinkevich 2000_ | Table 12, p. 13, row 13; `ORC-HN34UL6CGG.cc7c65` | | ### 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 Fe2Gd | Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective | |---:|---|---:|---:|---|---:|---:|---:|---:| | -11.6 | kJ/mol-atom | 2 | 0.05 | 3.5 (unknown, calibrated) | | | | 3.5 | | -11.6 | per mol-atom | 2 | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom | | | | 2 | | -11.6 | kJ/mol-atom | 2 | 5.000e-4 | 3.5 (unknown, calibrated) | | | | 3.5 | | -3.5 | kJ/mol-atom | 1.5 | 0.05 | 3.5 (unknown, calibrated) | | | | 3.5 | | -3.5 | per mol-atom | 1.5 | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom | | | | 1.5 | | -3.5 | kJ/mol-atom | 1.5 | 5.000e-4 | 3.5 (unknown, calibrated) | | | | 3.5 | | -6.81 | kJ/mol-atom | | 0.005 | 3.9 (model_calculated, calibrated) | | | | 3.9 | | -6.81 | per mol-atom | | 0.005 | unit 'per mol-atom' not convertible to kJ/mol-atom | | | | unit 'per mol-atom' not convertible to kJ/mol-atom | | -5.94 | per mol-atom | | 0.005 | unit 'per mol-atom' not convertible to kJ/mol-atom | | | | unit 'per mol-atom' not convertible to kJ/mol-atom | | -5.94 | kJ/mol-atom | | 0.005 | 3.9 (model_calculated, calibrated) | | | | 3.9 | | -4.59 | kJ/mol-atom | | 0.005 | 3.9 (model_calculated, calibrated) | | | | 3.9 | | -4.59 | per mol-atom | | 0.005 | unit 'per mol-atom' not convertible to kJ/mol-atom | | | | unit 'per mol-atom' not convertible to kJ/mol-atom | | -4.38 | kJ/mol-atom | | 0.005 | 3.9 (model_calculated, calibrated) | | | | 3.9 | | -4.38 | per mol-atom | | 0.005 | unit 'per mol-atom' not convertible to kJ/mol-atom | | | | unit 'per mol-atom' not convertible to kJ/mol-atom | ## 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 Fe2Gd | Source | Entry | kJ/mol-atom | eV/atom | Space group | E above hull (kJ/mol-atom) | E above hull (eV/atom) | Theoretical | |---|---|---:|---:|---|---:|---:|---| | Materials Project | mp-aaaabdsr | 1.566 | 0.016234 | Fd-3m | 1.9773 | 0.0205 | no | | OQMD | oqmd-18836 | -3.181 | -0.032969 | Fd-3m | 0.0306 | 3.000e-4 | 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. Matvei Zinkevich, Norbert Mattern, Hans‐Jürgen Seifert, Eberhard Gmelin, A thermodynamic assessment of the Fe‐Gd‐Mo system, Scand Jof Metallurgy 31, 34-51 (2002). [doi:10.1034/j.1600-0692.2002.311310106.x](https://doi.org/10.1034/j.1600-0692.2002.311310106.x) 2. M. Zinkevich, N. Mattern, H. J. Seifert, Reassessment of the Fe-Gd (Iron-Gadolinum) system, JPE 21, 385-394 (2000). [doi:10.1361/105497100770339923](https://doi.org/10.1361/105497100770339923) ## 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=\, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).