# Ir–W phases

> Ir–W system: 8 phases (tier A 6, liquid 1, needs_review 1); 7 stable in a calculated diagram in the ORCHID phase registry, with names, structure type when the stored evidence supports an assignment under the stated tier rules, calculated stability, verbatim TDB PHASE/CONSTITUENT statements and example references.

HTML: https://data.orchid-project.org/phases/pages/IR-W.html · Markdown: https://data.orchid-project.org/phases/pages/IR-W.md

8 phases (tier A 6, liquid 1, needs_review 1); 7 stable in a calculated diagram. Structure types are assigned only when the stored evidence supports an assignment under the stated tier rules (tier A: standard phase name; tier B: unique Materials Project + OQMD on-hull match, DFT-supported; tier C: one structure stated by the assessment's crystallographic table, assessor-stated); other phases list candidates and are marked needs_review. Stability is from phase diagrams calculated with pycalphad from the SGTE binary collection (evidence class: model).

Data: [interactive registry](https://orchid-project.org/phases/?q=IR-W) · [full JSON](https://data.orchid-project.org/phases/systems/IR-W.json) · [Ir–W system page](https://data.orchid-project.org/systems/IR-W.html) · [Markdown](https://data.orchid-project.org/phases/pages/IR-W.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md)

Table: Phases of the Ir–W system (8)

| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---:|---:|
| [BCC_A2](#phase-ir-w-bcc-a2); _phase:ir-w:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–3999.88 K, x(W) 0.93883–1 | 0 | 1 |
| [FCC_A1](#phase-ir-w-fcc-a1); _phase:ir-w:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–2719 K, x(W) 0–0.20837 | 0 | 1 |
| [HCP_A3](#phase-ir-w-hcp-a3); _phase:ir-w:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | not stable in 1 calculated diagram(s) | 0 | 1 |
| [IR3W_D019](#phase-ir-w-ir3w-d019); _phase:ir-w:ir3w-d019_ | Ni3Sn · D0_19 · hP8 · P6_3/mmc (194) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1921.14 K, x(W) 0.16092–0.33617 | 0 | 1 |
| [IRW_A3](#phase-ir-w-irw-a3); _phase:ir-w:irw-a3_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 1507.94–2790 K, x(W) 0.23656–0.60218 | 0 | 1 |
| [IRW_B19](#phase-ir-w-irw-b19); _phase:ir-w:irw-b19_ | AuCd · B19 · oP4 · Pmma (51) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1900 K, x(W) 0.47838–0.5 | 0 | 1 |
| [IRW3_D8B](#phase-ir-w-irw3-d8b); _phase:ir-w:irw3-d8b_ | sigma-CrFe · D8_b · tP30 · P4_2/mnm (136) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 2074.88–2846.18 K, x(W) 0.74814–0.7995 | 0 | 1 |
| [LIQUID](#phase-ir-w-liquid); _phase:ir-w:liquid_ | liquid | liquid | stable in 1 of 1 calculated diagram(s): 2579.39–4000 K, x(W) 0–1 | 0 | 1 |

## BCC_A2 (Ir–W)

- Id: `phase:ir-w:bcc-a2`; status `assigned`
- Structure: W · A2 · cI2 · Im-3m (229); type `st:a2-w-ci2`; tier A: standard phase name; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 300–3999.88 K, x(W) 0.93883–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ir-w:bcc-a2)

Names (2): _corpus: _corpus:phase:ir-w:bcc-a2  
_tdb: _tdb:IrW-20Hua.tdb:BCC_A2  


### TDB models of BCC_A2 (1): PHASE and CONSTITUENT statements as written

[IrW-20Hua.tdb](https://orchid-project.org/data/databases/sgte-binary/IrW-20Hua.tdb): BCC_A2, type code %B, sha256 `ad9a9f3cc83e1154…`

~~~~text
35: PHASE BCC_A2 %B 2 1 3 !
36: CONST BCC_A2 : IR W% : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.2298/JMMB190211001H](https://doi.org/10.2298/JMMB190211001H) Y.-Y. Huang, B. Wu, F. Li, L.-L. Chen, Z.-X. Deng, K. Chang, J. Mining Metall. B, 56, 109-18(2020).  
_assessment that models this phase_

## FCC_A1 (Ir–W)

- Id: `phase:ir-w:fcc-a1`; status `assigned`
- Structure: Cu · A1 · cF4 · Fm-3m (225); type `st:a1-cu-cf4`; tier A: standard phase name; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 300–2719 K, x(W) 0–0.20837
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ir-w:fcc-a1)

Names (2): _corpus: _corpus:phase:ir-w:fcc-a1  
_tdb: _tdb:IrW-20Hua.tdb:FCC_A1  


### TDB models of FCC_A1 (1): PHASE and CONSTITUENT statements as written

[IrW-20Hua.tdb](https://orchid-project.org/data/databases/sgte-binary/IrW-20Hua.tdb): FCC_A1, type code %A, sha256 `ad9a9f3cc83e1154…`

~~~~text
30: PHASE FCC_A1 %A 2 1 1 !
31: CONST FCC_A1 : IR% W : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.2298/JMMB190211001H](https://doi.org/10.2298/JMMB190211001H) Y.-Y. Huang, B. Wu, F. Li, L.-L. Chen, Z.-X. Deng, K. Chang, J. Mining Metall. B, 56, 109-18(2020).  
_assessment that models this phase_

## HCP_A3 (Ir–W)

- Id: `phase:ir-w:hcp-a3`; status `assigned`
- Structure: Mg · A3 · hP2 · P6_3/mmc (194); type `st:a3-mg-hp2`; tier A: standard phase name; confidence high
- Stability: not stable in 1 calculated diagram(s)
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ir-w:hcp-a3)

Names (2): _corpus: _corpus:phase:ir-w:hcp-a3  
_tdb: _tdb:IrW-20Hua.tdb:HCP_A3  


### TDB models of HCP_A3 (1): PHASE and CONSTITUENT statements as written

[IrW-20Hua.tdb](https://orchid-project.org/data/databases/sgte-binary/IrW-20Hua.tdb): HCP_A3, type code %A, sha256 `ad9a9f3cc83e1154…`

~~~~text
40: PHASE HCP_A3 %A 2 1 0.5 !
41: CONST HCP_A3 : IR W : VA: !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.2298/JMMB190211001H](https://doi.org/10.2298/JMMB190211001H) Y.-Y. Huang, B. Wu, F. Li, L.-L. Chen, Z.-X. Deng, K. Chang, J. Mining Metall. B, 56, 109-18(2020).  
_assessment that models this phase_

## IR3W_D019 (Ir–W)

- Id: `phase:ir-w:ir3w-d019`; status `assigned`
- Structure: Ni3Sn · D0_19 · hP8 · P6_3/mmc (194); type `st:d0-19-ni3sn-hp8`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in IrW-20Hua.tdb also describes the disordered state
- Stability: stable in 1 of 1 calculated diagram(s): 300–1921.14 K, x(W) 0.16092–0.33617
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ir-w:ir3w-d019)

Names (2): _corpus: _corpus:phase:ir-w:ir3w-d019  
_tdb: _tdb:IrW-20Hua.tdb:IR3W_D019  


### TDB models of IR3W_D019 (1): PHASE and CONSTITUENT statements as written

[IrW-20Hua.tdb](https://orchid-project.org/data/databases/sgte-binary/IrW-20Hua.tdb): IR3W_D019, type code %, sha256 `ad9a9f3cc83e1154…`

~~~~text
45: PHASE IR3W_D019 %  2 3 1 !
46: CONST IR3W_D019 : IR% W : IR W% : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.2298/JMMB190211001H](https://doi.org/10.2298/JMMB190211001H) Y.-Y. Huang, B. Wu, F. Li, L.-L. Chen, Z.-X. Deng, K. Chang, J. Mining Metall. B, 56, 109-18(2020).  
_assessment that models this phase_

## IRW_A3 (Ir–W)

- Id: `phase:ir-w:irw-a3`; status `needs_review`
- No structure assigned. Why: assessment_declared_blocked_by:order_disorder_ambiguity; order_disorder_ambiguity:IrW-20Hua.tdb_model_is_partitioned
- Candidate (dft_mp): P6_3/mmc (194) — on-hull MP Ir3W at x(W)=0.2500
- Candidate (dft_mp): Pmma (51) — on-hull MP IrW at x(W)=0.5000
- Candidate (dft_oqmd): Pmma (51) — on-hull OQMD Ir1 W1 at x(W)=0.5000
- Candidate (dft_oqmd): P63/mmc (194) — on-hull OQMD Ir3 W1 at x(W)=0.2500
- Candidate (name_token): Mg · A3 · hP2 · P6_3/mmc (194) — Strukturbericht/word 'A3' in the TDB name
- Candidate (sgte_mmc2): Mg · A3 · hP2 · P6_3/mmc (194) — Hallstedt 2025 mmc2 row for IRW_A3: IrW (high T)
- Candidate (tdb_comment): Mg · hP2 · P6_3/mmc — IrW-20Hua.tdb: 'Prototype Mg (hP2, P6_3/mmc), epsilon, this is hcp!'
- Stability: stable in 1 of 1 calculated diagram(s): 1507.94–2790 K, x(W) 0.23656–0.60218
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ir-w:irw-a3)

Names (2): _corpus: _corpus:phase:ir-w:irw-a3  
_tdb: _tdb:IrW-20Hua.tdb:IRW_A3  


### TDB models of IRW_A3 (1): PHASE and CONSTITUENT statements as written

[IrW-20Hua.tdb](https://orchid-project.org/data/databases/sgte-binary/IrW-20Hua.tdb): IRW_A3, type code %, sha256 `ad9a9f3cc83e1154…`

~~~~text
55: PHASE IRW_A3 %  2 1 1 !
56: CONST IRW_A3 : IR% W : IR W% : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.2298/JMMB190211001H](https://doi.org/10.2298/JMMB190211001H) Y.-Y. Huang, B. Wu, F. Li, L.-L. Chen, Z.-X. Deng, K. Chang, J. Mining Metall. B, 56, 109-18(2020).  
_assessment that models this phase_

## IRW_B19 (Ir–W)

- Id: `phase:ir-w:irw-b19`; status `assigned`
- Structure: AuCd · B19 · oP4 · Pmma (51); type `st:b19-aucd-op4`; tier A: standard phase name; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 300–1900 K, x(W) 0.47838–0.5
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ir-w:irw-b19)

Names (2): _corpus: _corpus:phase:ir-w:irw-b19  
_tdb: _tdb:IrW-20Hua.tdb:IRW_B19  


### TDB models of IRW_B19 (1): PHASE and CONSTITUENT statements as written

[IrW-20Hua.tdb](https://orchid-project.org/data/databases/sgte-binary/IrW-20Hua.tdb): IRW_B19, type code %, sha256 `ad9a9f3cc83e1154…`

~~~~text
50: PHASE IRW_B19 %  2 1 1 !
51: CONST IRW_B19 : IR : IR W% : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.2298/JMMB190211001H](https://doi.org/10.2298/JMMB190211001H) Y.-Y. Huang, B. Wu, F. Li, L.-L. Chen, Z.-X. Deng, K. Chang, J. Mining Metall. B, 56, 109-18(2020).  
_assessment that models this phase_

## IRW3_D8B (Ir–W)

- Id: `phase:ir-w:irw3-d8b`; status `assigned`
- Structure: sigma-CrFe · D8_b · tP30 · P4_2/mnm (136); type `st:d8-b-sigma-crfe-tp30`; tier A: standard phase name; confidence high
- Caveat: partitioned order/disorder model in IrW-20Hua.tdb also describes the disordered state
- Stability: stable in 1 of 1 calculated diagram(s): 2074.88–2846.18 K, x(W) 0.74814–0.7995
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ir-w:irw3-d8b)

Names (2): _corpus: _corpus:phase:ir-w:irw3-d8b  
_tdb: _tdb:IrW-20Hua.tdb:IRW3_D8B  


### TDB models of IRW3_D8B (1): PHASE and CONSTITUENT statements as written

[IrW-20Hua.tdb](https://orchid-project.org/data/databases/sgte-binary/IrW-20Hua.tdb): IRW3_D8B, type code %, sha256 `ad9a9f3cc83e1154…`

~~~~text
60: PHASE IRW3_D8B %  2 1 3 !
61: CONST IRW3_D8B : IR% W : IR W% : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.2298/JMMB190211001H](https://doi.org/10.2298/JMMB190211001H) Y.-Y. Huang, B. Wu, F. Li, L.-L. Chen, Z.-X. Deng, K. Chang, J. Mining Metall. B, 56, 109-18(2020).  
_assessment that models this phase_

## LIQUID (Ir–W)

- Id: `phase:ir-w:liquid`; status `assigned`
- Structure: liquid; type `st:liquid`; liquid; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 2579.39–4000 K, x(W) 0–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ir-w:liquid)

Names (2): _corpus: _corpus:phase:ir-w:liquid  
_tdb: _tdb:IrW-20Hua.tdb:LIQUID  


### TDB models of LIQUID (1): PHASE and CONSTITUENT statements as written

[IrW-20Hua.tdb](https://orchid-project.org/data/databases/sgte-binary/IrW-20Hua.tdb): LIQUID, type code %, sha256 `ad9a9f3cc83e1154…`

~~~~text
25: PHASE LIQUID:L % 1 1 !
26: CONST LIQUID:L : IR W : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.2298/JMMB190211001H](https://doi.org/10.2298/JMMB190211001H) Y.-Y. Huang, B. Wu, F. Li, L.-L. Chen, Z.-X. Deng, K. Chang, J. Mining Metall. B, 56, 109-18(2020).  
_assessment that models this phase_

## Please cite

- R. Arróyave, J. Saal, D. Shin, ORCHID-Registry: phase registry of binary systems (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23735970
- 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 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); the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work).

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_phase_registry_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Registry: phase registry of binary systems}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735970},
  url       = {https://doi.org/10.5281/zenodo.23735970},
  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 the ORCHID phase registry and the sources named on the page (TDB assessments, Hallstedt 2025, Materials Project, OQMD). TDB statements are quoted as written; parameter expressions are not reproduced. Field reference: [SCHEMA.md](https://data.orchid-project.org/phases/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt).