# Ir system > Ir system: 18 accepted literature values (crystal structure 15, formation 3) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote. HTML: https://data.orchid-project.org/systems/IR.html · Markdown: https://data.orchid-project.org/systems/IR.md 18 accepted literature values from 6 paper(s) (experimental 6, model 8, unspecified 4); 0 calculated phase diagram(s). Data: [JSON](https://data.orchid-project.org/literature/systems/IR.json) · [CSV](https://data.orchid-project.org/systems/IR.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#IR) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/IR.html) · [Markdown](https://data.orchid-project.org/systems/IR.md) Table: Accepted values by evidence class | Evidence class | Values | |---|---:| | experimental | 6 | | model | 8 | | unspecified | 4 | Table: Accepted values by property group | Property group | Values | |---|---:| | formation | 3 | | crystal structure | 15 | ## Formation enthalpies Literature values in kJ/mol-atom where the per-atom basis is known. DFT columns: the lowest-energy entry at the same composition (Materials Project 2026.04.13, OQMD v1.8; different energy references, never averaged), from [dft_parity.json](https://data.orchid-project.org/literature/dft_parity.json). Table: Enthalpies of formation, Ir system (3) | Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote | |---|---|---:|---:|---|---:|---:|---|---|---| | A1-Al | | 0 kJ/mol-atom | 0 | model | | | [1] Abe 2008 | Table 2, p. 3, row 21; `ORC-PSDZU7YMNB.ed0174` | | | A1-Ir | | 0 kJ/mol-atom | 0 | model | | | [1] Abe 2008 | Table 2, p. 3, row 21; `ORC-PSDZU7YMNB.abef50` | | | A2-Ir | | 8.8 kJ/mol-atom | 0 | model | | | [1] Abe 2008 | Table 2, p. 3, row 24; `ORC-3GMHV2XSSV` | | ## Other properties ### Crystal structure (15) Table: Crystal structure, Ir system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Lattice a; _printed: a_ | 3.888 Å | 0 | A1-Ir; _alloy: Ir 1_ | model | [1] Abe 2008 | Table 2, p. 3, row 21; `ORC-4DFZPM6XU2` | | | Lattice a; _printed: a_ | 3.839 Å | | A1-Ir; _alloy: Ir 1_ | experimental | [1] Abe 2008; _cites Schroder 1972_ | Table 2, p. 3, row 22; `ORC-6RWKLMXOX3.c57815` | | | Lattice a; _printed: a_ | 3.119 Å | 0 | A2-Ir; _alloy: Ir 1_ | model | [1] Abe 2008 | Table 2, p. 3, row 24; `ORC-BCK2PDII5Z.9ca740` | | | Lattice a; _printed: a_ | 3.839 Å | | Al–Ir; _alloy: Ir 1_ | experimental | [1] Abe 2008; _cites Schroder 1972_ | Table 2, p. 3, row 22; `ORC-6RWKLMXOX3.3bedbc` | | | Lattice a | 3.885 Å | | Ir | model | [2] Huang 2020 | Table 1, p. 3, row 14; `ORC-VJOJCE3PNJ.33b8c1` | | | Lattice a | 3.8392 Å | 298.15 | Ir; _Ir: Ir 1_ | unspecified | [3] Anderson 1992 | Table 2, p. 1, row 18; `ORC-3N2QJJH3K5` | | | Lattice a | 3.839 Å | 298.15 | Ir | experimental | [2] Huang 2020; _cites Michalik 1963_ | Table 1, p. 3, row 13; `ORC-UZTCAQ4HP6.152a13` | | | Lattice a | 3.8391 Å | 298.15 | Ir(s); _Ir(s): Ir 1_ | unspecified | [4] Karakaya 1986 | Table 1, p. 2, row 2; `ORC-FV3BPEFABT` | | | Lattice a | 3.8391 Å | 298.15 | Ir(s); _Ir(s): Ir 1_ | unspecified | [5] Karakaya 1986; _cites ref. 1_ | Table 1, p. 1, row 2; `ORC-MA5KC5CUJD.8217c7` | | | Lattice a | 3.839 Å | 303.15 | (Ir); _alloy: Ir 1_ | experimental | [6] Chakrabarti 1987; _cites Singh 1969_ | Table 3, p. 3, row 6; `ORC-7BH6GCFV5Z` | | | Lattice b | 3.885 Å | | Ir | model | [2] Huang 2020 | Table 1, p. 3, row 14; `ORC-VJOJCE3PNJ.37abe5` | | | Lattice b | 3.839 Å | 298.15 | Ir | experimental | [2] Huang 2020; _cites Michalik 1963_ | Table 1, p. 3, row 13; `ORC-UZTCAQ4HP6.e75b2b` | | | Lattice c | 3.885 Å | | Ir | model | [2] Huang 2020 | Table 1, p. 3, row 14; `ORC-VJOJCE3PNJ.c7e2a4` | | | Lattice c | 3.839 Å | 298.15 | Ir | experimental | [2] Huang 2020; _cites Michalik 1963_ | Table 1, p. 3, row 13; `ORC-UZTCAQ4HP6.76f357` | | | lattice unspecified axis | 3.8391 Å | 298.15 | Ir(s); _Ir(s): Ir 1_ | unspecified | [5] Karakaya 1986; _cites ref. 1_ | Table 1, p. 1, row 2; `ORC-MA5KC5CUJD.8f8811` | | ## Sources Reporting papers the values were read from (a value cited from another work names that work in its row). 1. T. Abe, C. Kocer, M. Ode, H. Murakami, Y. Yamabe-Mitarai, K. Hashimoto et al., Thermodynamic re-assessment of the Al–Ir system, Calphad 32, 686-692 (2008). [doi:10.1016/j.calphad.2008.09.014](https://doi.org/10.1016/j.calphad.2008.09.014) 2. Y.-Y. Huang, B. Wu, F. Li, L.-L. Chen, Z.-X. Deng, K. Chang, First-principles and CALPHAD-type study of the Ir-Mo and Ir-W systems, J min metall B Metall 56, 109-118 (2020). [doi:10.2298/jmmb190211001h](https://doi.org/10.2298/jmmb190211001h) 3. T. J. Anderson, I. Ansara, The Ga-Sn (gallium-tin) system, JPE 13, 181-189 (1992). [doi:10.1007/bf02667485](https://doi.org/10.1007/bf02667485) 4. I. Karakaya, W. T. Thompson, The Ag−Ir (Silver-Iridium) system, Bulletin of Alloy Phase Diagrams 7, 359-360 (1986). [doi:10.1007/bf02873021](https://doi.org/10.1007/bf02873021) 5. I. Karakaya, W. T. Thompson, The Ag−Os (Silver-Osmium) system, Bulletin of Alloy Phase Diagrams 7, 360-362 (1986). [doi:10.1007/bf02873022](https://doi.org/10.1007/bf02873022) 6. D. J. Chakrabarti, D. E. Laughlin, The Cu−Ir (Copper-Iridium) system, JPE 8, 132-136 (1987). [doi:10.1007/bf02873198](https://doi.org/10.1007/bf02873198) ## 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 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); 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; 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). 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_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/).