# Fe2Ho: enthalpy of formation > Enthalpy of formation of Fe2Ho: 10 literature value(s) with sources, pages and quotes, from ORCHID. HTML: https://data.orchid-project.org/compounds/Fe2Ho.html · Markdown: https://data.orchid-project.org/compounds/Fe2Ho.md 10 accepted literature formation-enthalpy value(s) (experimental 4, model 5, DFT 1). Systems: [Fe–Ho](https://data.orchid-project.org/systems/FE-HO.html) ## Literature values Table: Enthalpy of formation of Fe2Ho reported in the literature (10) | Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote | |---:|---|---:|---|---|---|---|---|---| | -6.2 kJ/mol (basis unstated) | Fe2Ho | 300 | experimental | Adiabatic Calo. | [Fe–Ho](https://data.orchid-project.org/systems/FE-HO.html) | [1] Kardellass 2014; _cites Germano 1981_ [doi](https://doi.org/10.1016/0022-4596%2881%2990500-4) | Table 3, p. 3, row 19; `ORC-O4O4JBXJXL.88ebbd` | | | -5.9 kJ/mol (basis unstated) | Fe2Ho | 290 | experimental | Adiabatic Calo. | [Fe–Ho](https://data.orchid-project.org/systems/FE-HO.html) | [1] Kardellass 2014; _cites Germano 1981_ [doi](https://doi.org/10.1016/0022-4596%2881%2990500-4) | Table 3, p. 3, row 18; `ORC-RV44IPUBUO.9c8eae` | | | -4.3 kJ/mol (basis unstated) | Fe2Ho | 298.15 | experimental | EMF | [Fe–Ho](https://data.orchid-project.org/systems/FE-HO.html) | [1] Kardellass 2014; _cites Latini 2013_ [doi](https://doi.org/10.1016/j.jct.2012.09.021) | Table 3, p. 3, row 14; `ORC-ZLQBKQ2PQ4.7e7a97` | | | -2.6 kJ/mol (basis unstated) ± 3.3 | Fe2Ho | 1373 | experimental | DSC | [Fe–Ho](https://data.orchid-project.org/systems/FE-HO.html) | [1] Kardellass 2014; _cites Meschel 2013_ [doi](https://doi.org/10.1016/j.jallcom.2012.11.035) | Table 3, p. 3, row 16; `ORC-NHNYJN3TVX.65dd16` | | | -6.2 kJ/mol (basis unstated) | Fe2Ho | 300 | model | Calculation | [Fe–Ho](https://data.orchid-project.org/systems/FE-HO.html) | [1] Kardellass 2014; _cites Germano 1981_ [doi](https://doi.org/10.1016/0022-4596%2881%2990500-4) | Table 3, p. 3, row 13; `ORC-VATGYD3ZK5.0981b4` | | | -3 kJ/mol (basis unstated) | Fe2Ho | 298.15 | model | Prediction | [Fe–Ho](https://data.orchid-project.org/systems/FE-HO.html) | [1] Kardellass 2014; _cites Kardellass 2013_ | Table 3, p. 3, row 11; `ORC-42OZZ22NRH.9d2805` | | | -2.97 kJ/mol (basis unstated) | Fe2Ho | 298.15 | model | Prediction | [Fe–Ho](https://data.orchid-project.org/systems/FE-HO.html) | [1] Kardellass 2014; _cites Pauling_ | Table 3, p. 3, row 20; `ORC-FJUGJ2NCVS.e15efe` | | | -2.9 kJ/mol (basis unstated) | Fe2Ho | 298.15 | model | Prediction | [Fe–Ho](https://data.orchid-project.org/systems/FE-HO.html) | [1] Kardellass 2014; _cites Niessen 1983_ [doi](https://doi.org/10.1016/0364-5916%2883%2990030-5) | Table 3, p. 3, row 12; `ORC-KHGK7NMZJP.7769eb` | | | -2.65 kJ/mol (basis unstated) | Fe2Ho | 298.15 | model | Optimization | [Fe–Ho](https://data.orchid-project.org/systems/FE-HO.html) | [1] Kardellass 2014 | Table 3, p. 3, row 17; `ORC-VUH3JZJG6S.85e37a` | | | -9.5 kJ/mol (basis unstated) | Fe2Ho | 298.15 | DFT | Ab initio | [Fe–Ho](https://data.orchid-project.org/systems/FE-HO.html) | [1] Kardellass 2014; _cites Pauling_ | Table 3, p. 3, row 15; `ORC-J5ZAPW5P3R.623911` | | ### 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 Fe2Ho | Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective | |---:|---|---:|---:|---|---:|---:|---:|---:| | -6.2 | kJ/mol (basis unstated) | | 0.05 | 10.5 (heat_content_calorimetry, calibrated) | | | | 10.5 | | -5.9 | kJ/mol (basis unstated) | | 0.05 | 10.5 (heat_content_calorimetry, calibrated) | | | | 10.5 | | -4.3 | kJ/mol (basis unstated) | | 0.05 | 13.8 (emf, cleaned_below_threshold) | | | | 13.8 | | -2.6 | kJ/mol (basis unstated) | 3.3 | 0.05 | 6 (dsc_dta, prior) | | | | 6 | | -6.2 | kJ/mol (basis unstated) | | 0.05 | 11.7 (model_calculated, calibrated) | | | | 11.7 | | -3 | kJ/mol (basis unstated) | | 0.05 | 11.7 (model_calculated, calibrated) | | | | 11.7 | | -2.97 | kJ/mol (basis unstated) | | 0.005 | 11.7 (model_calculated, calibrated) | | | | 11.7 | | -2.9 | kJ/mol (basis unstated) | | 0.05 | 11.7 (model_calculated, calibrated) | | | | 11.7 | | -2.65 | kJ/mol (basis unstated) | | 0.005 | 11.7 (model_calculated, calibrated) | | | | 11.7 | | -9.5 | kJ/mol (basis unstated) | | 0.05 | 11.79 (dft, calibrated) | | | | 11.79 | ## Sources 1. S. Kardellass, C. Servant, N. Selhaoui, A. Iddaoudi, M. Ait Amar, L. Bouirden, A thermodynamic assessment of the Iron+Holmium phase diagram, The Journal of Chemical Thermodynamics 74, 78-84 (2014). [doi:10.1016/j.jct.2013.11.037](https://doi.org/10.1016/j.jct.2013.11.037) ## 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/).