# Mg3Sb2: enthalpy of formation > Enthalpy of formation of Mg3Sb2: 16 literature value(s) with sources, pages and quotes and DFT values (Materials Project / OQMD), from ORCHID. HTML: https://data.orchid-project.org/compounds/Mg3Sb2.html · Markdown: https://data.orchid-project.org/compounds/Mg3Sb2.md 16 accepted literature formation-enthalpy value(s) (experimental 4, model 12); experimental median -47 kJ/mol-atom (n = 1); Materials Project -43.056 kJ/mol-atom (mp-aaacqblj); OQMD -36.528 kJ/mol-atom (oqmd-116230). Systems: [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) ## Literature values Table: Enthalpy of formation of Mg3Sb2 reported in the literature (16) | Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote | |---:|---|---:|---|---|---|---|---|---| | -299 kJ/mol (basis unstated) ± 3 | α-Mg3Sb2 | 900 | experimental | emf measurements | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [1] Balakumar 2005; _cites Rao 1971_ | Table 8, p. 9, row 1; `ORC-S73UBRDYOW.bf3b44` | | | -285 kJ/mol (basis unstated) | α-Mg3Sb2 | 923 | experimental | high temperature calorimetric measurements | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [1] Balakumar 2005; _cites Kubaschewski 1939_ | Table 8, p. 9, row 3; `ORC-74VG6UDUNM` | | | -235 kJ/mol (basis unstated) ± 6 | α-Mg3Sb2 | 773 | experimental | emf measurements | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [1] Balakumar 2005; _cites Eremenko 1964_ | Table 8, p. 9, row 2; `ORC-5K5LBJTMYL.bb5e36` | | | -47 kJ/mol-atom ± 1.2 | Mg3Sb2 | 773 | experimental | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [2] Jönsson 1987; _cites Eremenko 1964_ | Table 1I, p. 4, row 6; `ORC-LOEUZNK44H.0d74e1` | | | -490 kJ/mol (basis unstated) | α-Mg3Sb2 | 298.15 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [1] Balakumar 2005 | Table 8, p. 9, row 6; `ORC-4VU7MLTQ6B.6995de` | | | -320 kJ/mol (basis unstated) ± 40 | α-Mg3Sb2 | 800 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [1] Balakumar 2005; _cites Hultgren 1973_ | Table 8, p. 9, row 4; `ORC-P3PERMDXQV.6fe0c8` | | | -300 kJ/mol (basis unstated) | α-Mg3Sb2 | 298.15 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [1] Balakumar 2005; _cites Barin 1977_ | Table 8, p. 9, row 5; `ORC-LGR5HFS5UH` | | | -64 kJ/mol-atom ± 8 | Mg3Sb2 | 800 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [2] Jönsson 1987; _cites Hultgren 1973_ | Table 1I, p. 4, row 8; `ORC-T7HTVUGFAK.701a22` | | | -60 kJ/mol-atom | Mg3Sb2 | 298.15 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [2] Jönsson 1987; _cites Barin 1977_ [doi](https://doi.org/10.1007/978-3-662-02293-1) | Table 1I, p. 4, row 2; `ORC-I5AHK7ATFQ.044853` | | | -59.8 kJ/mol-atom ± 0.6 | Mg3Sb2 | 900 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [2] Jönsson 1987; _cites Rao 1971_ | Table 1I, p. 4, row 10; `ORC-OH45YAVE2N.9feac7` | | | -57 kJ/mol-atom | Mg3Sb2 | 923 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [2] Jönsson 1987; _cites Kubaschewski 1939_ | Table 1I, p. 4, row 12; `ORC-B6MRMXFRU4.88f72c` | | | -55.2 kJ/mol-atom | Mg3Sb2 | 298.15 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [2] Jönsson 1987 | Table 1I, p. 4, row 1; `ORC-D4BOPSKDPA.88eb87` | | | -53.2 kJ/mol-atom | Mg3Sb2 | 773 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [2] Jönsson 1987 | Table 1I, p. 4, row 5; `ORC-V6GXATDZD2.4ff1ca` | | | -53.2 kJ/mol-atom | Mg3Sb2 | 800 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [2] Jönsson 1987 | Table 1I, p. 4, row 7; `ORC-WGUPYZ76WC.210064` | | | -52.6 kJ/mol-atom | Mg3Sb2 | 900 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [2] Jönsson 1987 | Table 1I, p. 4, row 9; `ORC-TN5CSURPLF.6cc7e2` | | | -52.4 kJ/mol-atom | Mg3Sb2 | 923 | model | | [Mg–Sb](https://data.orchid-project.org/systems/MG-SB.html) | [2] Jönsson 1987 | Table 1I, p. 4, row 11; `ORC-MQX3HO7MYO.7825da` | | ### 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 Mg3Sb2 | Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective | |---:|---|---:|---:|---|---:|---:|---:|---:| | -299 | kJ/mol (basis unstated) | 3 | 0.5 | 23 (emf, cleaned_below_threshold) | | | | 23 | | -285 | kJ/mol (basis unstated) | | 0.5 | 16 (solution_reaction_calorimetry, calibrated) | | | | 16 | | -235 | kJ/mol (basis unstated) | 6 | 0.5 | 23 (emf, cleaned_below_threshold) | | | | 23 | | -47 | kJ/mol-atom | 1.2 | 0.01 | 3.5 (unknown, calibrated) | | | | 3.5 | | -490 | kJ/mol (basis unstated) | | 0.5 | 19.5 (model_calculated, calibrated) | | | | 19.5 | | -320 | kJ/mol (basis unstated) | 40 | 0.5 | 19.5 (model_calculated, calibrated) | | | | 40 | | -300 | kJ/mol (basis unstated) | | 0.5 | 19.5 (model_calculated, calibrated) | | | | 19.5 | | -64 | kJ/mol-atom | 8 | 0.1 | 3.9 (model_calculated, calibrated) | | | | 8 | | -60 | kJ/mol-atom | | 0.01 | 3.9 (model_calculated, calibrated) | | | | 3.9 | | -59.8 | kJ/mol-atom | 0.6 | 0.1 | 3.9 (model_calculated, calibrated) | | | | 3.9 | | -57 | kJ/mol-atom | | 0.01 | 3.9 (model_calculated, calibrated) | | | | 3.9 | | -55.2 | kJ/mol-atom | | 0.01 | 3.9 (model_calculated, calibrated) | | | | 3.9 | | -53.2 | kJ/mol-atom | | 0.1 | 3.9 (model_calculated, calibrated) | | | | 3.9 | | -53.2 | kJ/mol-atom | | 0.1 | 3.9 (model_calculated, calibrated) | | | | 3.9 | | -52.6 | kJ/mol-atom | | 0.01 | 3.9 (model_calculated, calibrated) | | | | 3.9 | | -52.4 | kJ/mol-atom | | 0.01 | 3.9 (model_calculated, calibrated) | | | | 3.9 | ## 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 Mg3Sb2 | Source | Entry | kJ/mol-atom | eV/atom | Space group | E above hull (kJ/mol-atom) | E above hull (eV/atom) | Theoretical | |---|---|---:|---:|---|---:|---:|---| | Materials Project | mp-aaacqblj | -43.056 | -0.446245 | Ia-3 | 0 | 0 | yes | | OQMD | oqmd-116230 | -36.528 | -0.378584 | Ia-3 | 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. T. Balakumar, M. Medraj, Thermodynamic modeling of the Mg–Al–Sb system, Calphad 29, 24-36 (2005). [doi:10.1016/j.calphad.2005.03.001](https://doi.org/10.1016/j.calphad.2005.03.001) 2. Björn Jönsson, John Ågren, A theoretical evaluation of chemical ordering and glass transition in liquid Mg-Sb alloys, Metall Trans A 18, 1395-1401 (1987). [doi:10.1007/bf02646653](https://doi.org/10.1007/bf02646653) ## 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/).