# As–Zn phases

> As–Zn system: 9 phases (tier A 5, tier C 2, 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/AS-ZN.html · Markdown: https://data.orchid-project.org/phases/pages/AS-ZN.md

9 phases (tier A 5, tier C 2, 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=AS-ZN) · [full JSON](https://data.orchid-project.org/phases/systems/AS-ZN.json) · [As–Zn system page](https://data.orchid-project.org/systems/AS-ZN.html) · [Markdown](https://data.orchid-project.org/phases/pages/AS-ZN.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md)

Table: Phases of the As–Zn system (9)

| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---:|---:|
| [RHOMBOHEDRAL_A7](#phase-as-zn-a7-rhombohedral); _phase:as-zn:a7-rhombohedral_ | alpha-As · A7 · hR2 · R-3m (166) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1093 K, x(As) 0.99997–1 | 0 | 1 |
| [BCC_A2](#phase-as-zn-bcc-a2); _phase:as-zn:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | not stable in 1 calculated diagram(s) | 0 | 1 |
| [FCC_A1](#phase-as-zn-fcc-a1); _phase:as-zn:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | not stable in 1 calculated diagram(s) | 0 | 1 |
| [HCP_A3](#phase-as-zn-hcp-a3); _phase:as-zn:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1147.68 K, x(As) 0–0 | 0 | 1 |
| [LIQUID](#phase-as-zn-liquid); _phase:as-zn:liquid_ | liquid | liquid | stable in 1 of 1 calculated diagram(s): 689.6–2500 K, x(As) 0–1 | 0 | 1 |
| [ZN3AS2_RT](#phase-as-zn-zn3as2); _phase:as-zn:zn3as2_ | Cd3As2 · tI160 · I4_1cd (110) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–462.6 K, x(As) 0.4–0.4 | 0 | 1 |
| [ZN3AS2_C1](#phase-as-zn-zn3as2-c1); _phase:as-zn:zn3as2-c1_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 923.97–1288.87 K, x(As) 0.4–0.4 | 0 | 1 |
| [ZN3AS2_D59](#phase-as-zn-zn3as2-d59); _phase:as-zn:zn3as2-d59_ | Zn3P2 · D5_9 · tP40 · P4_2/nmc (137) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 462.6–923.97 K, x(As) 0.4–0.4 | 0 | 1 |
| [ZNAS2](#phase-as-zn-znas2); _phase:as-zn:znas2_ | ZnAs2 · mP24 · P2_1/c (14) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1043.28 K, x(As) 0.66667–0.67 | 0 | 1 |

## RHOMBOHEDRAL_A7 (As–Zn)

- Id: `phase:as-zn:a7-rhombohedral`; status `assigned`
- Structure: alpha-As · A7 · hR2 · R-3m (166); type `st:a7-alpha-as-hr2`; tier A: standard phase name; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 300–1093 K, x(As) 0.99997–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:as-zn:a7-rhombohedral)

Names (2): _corpus: _corpus:phase:as-zn:a7-rhombohedral  
_tdb: _tdb:ZnAs-15Gha.tdb:RHOMBOHEDRAL_A7  


### TDB models of RHOMBOHEDRAL_A7 (1): PHASE and CONSTITUENT statements as written

[ZnAs-15Gha.tdb](https://orchid-project.org/data/databases/sgte-binary/ZnAs-15Gha.tdb): RHOMBOHEDRAL_A7, type code %, sha256 `6243128aa65ab792…`

~~~~text
51: PHASE RHOMBOHEDRAL_A7 % 1 1 !
52: CONST RHOMBOHEDRAL_A7 : AS% ZN : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jallcom.2015.03.051](https://doi.org/10.1016/j.jallcom.2015.03.051) Masoomeh Ghasemi, Jonas Johansson, Thermodynamic assessment of the As–Zn and As–Ga–Zn systems, Journal of Alloys and Compounds 638, 95-102 (2015).  
_assessment that models this phase_

## BCC_A2 (As–Zn)

- Id: `phase:as-zn:bcc-a2`; status `assigned`
- Structure: W · A2 · cI2 · Im-3m (229); type `st:a2-w-ci2`; 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:as-zn:bcc-a2)

Names (2): _corpus: _corpus:phase:as-zn:bcc-a2  
_tdb: _tdb:ZnAs-15Gha.tdb:BCC_A2  


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

[ZnAs-15Gha.tdb](https://orchid-project.org/data/databases/sgte-binary/ZnAs-15Gha.tdb): BCC_A2, type code %B, sha256 `6243128aa65ab792…`

~~~~text
41: PHASE BCC_A2 %B 2 1 3 !
42: CONST BCC_A2 : AS ZN : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jallcom.2015.03.051](https://doi.org/10.1016/j.jallcom.2015.03.051) Masoomeh Ghasemi, Jonas Johansson, Thermodynamic assessment of the As–Zn and As–Ga–Zn systems, Journal of Alloys and Compounds 638, 95-102 (2015).  
_assessment that models this phase_

## FCC_A1 (As–Zn)

- Id: `phase:as-zn:fcc-a1`; status `assigned`
- Structure: Cu · A1 · cF4 · Fm-3m (225); type `st:a1-cu-cf4`; 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:as-zn:fcc-a1)

Names (2): _corpus: _corpus:phase:as-zn:fcc-a1  
_tdb: _tdb:ZnAs-15Gha.tdb:FCC_A1  


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

[ZnAs-15Gha.tdb](https://orchid-project.org/data/databases/sgte-binary/ZnAs-15Gha.tdb): FCC_A1, type code %A, sha256 `6243128aa65ab792…`

~~~~text
36: PHASE FCC_A1 %A 2 1 1 !
37: CONST FCC_A1 : AS ZN : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jallcom.2015.03.051](https://doi.org/10.1016/j.jallcom.2015.03.051) Masoomeh Ghasemi, Jonas Johansson, Thermodynamic assessment of the As–Zn and As–Ga–Zn systems, Journal of Alloys and Compounds 638, 95-102 (2015).  
_assessment that models this phase_

## HCP_A3 (As–Zn)

- Id: `phase:as-zn: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: stable in 1 of 1 calculated diagram(s): 300–1147.68 K, x(As) 0–0
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:as-zn:hcp-a3)

Names (2): _corpus: _corpus:phase:as-zn:hcp-a3  
_tdb: _tdb:ZnAs-15Gha.tdb:HCP_A3  


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

[ZnAs-15Gha.tdb](https://orchid-project.org/data/databases/sgte-binary/ZnAs-15Gha.tdb): HCP_A3, type code %A, sha256 `6243128aa65ab792…`

~~~~text
46: PHASE HCP_A3 %A 2 1 0.5 !
47: CONST HCP_A3 : AS ZN% : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jallcom.2015.03.051](https://doi.org/10.1016/j.jallcom.2015.03.051) Masoomeh Ghasemi, Jonas Johansson, Thermodynamic assessment of the As–Zn and As–Ga–Zn systems, Journal of Alloys and Compounds 638, 95-102 (2015).  
_assessment that models this phase_

## LIQUID (As–Zn)

- Id: `phase:as-zn:liquid`; status `assigned`
- Structure: liquid; type `st:liquid`; liquid; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 689.6–2500 K, x(As) 0–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:as-zn:liquid)

Names (2): _corpus: _corpus:phase:as-zn:liquid  
_tdb: _tdb:ZnAs-15Gha.tdb:LIQUID  


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

[ZnAs-15Gha.tdb](https://orchid-project.org/data/databases/sgte-binary/ZnAs-15Gha.tdb): LIQUID, type code %, sha256 `6243128aa65ab792…`

~~~~text
31: PHASE LIQUID:L % 1 1 !
32: CONST LIQUID:L : AS ZN ZN3AS2 : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jallcom.2015.03.051](https://doi.org/10.1016/j.jallcom.2015.03.051) Masoomeh Ghasemi, Jonas Johansson, Thermodynamic assessment of the As–Zn and As–Ga–Zn systems, Journal of Alloys and Compounds 638, 95-102 (2015).  
_assessment that models this phase_

## ZN3AS2_RT (As–Zn)

- Id: `phase:as-zn:zn3as2`; status `assigned`
- Structure: Cd3As2 · tI160 · I4_1cd (110); type `st:cd3as2-ti160`; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated
- Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) [doi:10.1016/j.calphad.2025.102833](https://doi.org/10.1016/j.calphad.2025.102833)
- Caveat: not certain from the name or DFT alone (no_structure_token, polymorph_family:other phases of this system have the same composition); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: As 0.4000, Zn 0.6000
- Stability: stable in 1 of 1 calculated diagram(s): 300–462.6 K, x(As) 0.4–0.4
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:as-zn:zn3as2)

Names (2): _corpus: _corpus:phase:as-zn:zn3as2  
_tdb: _tdb:ZnAs-15Gha.tdb:ZN3AS2_RT  


### TDB models of ZN3AS2_RT (1): PHASE and CONSTITUENT statements as written

[ZnAs-15Gha.tdb](https://orchid-project.org/data/databases/sgte-binary/ZnAs-15Gha.tdb): ZN3AS2_RT, type code %, sha256 `6243128aa65ab792…`

~~~~text
56: PHASE ZN3AS2_RT % 2 3 2 !
57: CONST ZN3AS2_RT : ZN : AS : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jallcom.2015.03.051](https://doi.org/10.1016/j.jallcom.2015.03.051) Masoomeh Ghasemi, Jonas Johansson, Thermodynamic assessment of the As–Zn and As–Ga–Zn systems, Journal of Alloys and Compounds 638, 95-102 (2015).  
_assessment that models this phase_

## ZN3AS2_C1 (As–Zn)

- Id: `phase:as-zn:zn3as2-c1`; status `needs_review`
- No structure assigned. Why: assessment_declared_blocked_by:stoichiometry_contradicts_C1; stoichiometry_contradicts_C1:ZnAs-15Gha.tdb
- Candidate (dft_mp): P4_2/nbc (133) — on-hull MP Zn3As2 at x(ZN)=0.6000
- Candidate (dft_oqmd): P42/nmc (137) — on-hull OQMD As2 Zn3 at x(ZN)=0.6000
- Candidate (name_token): CaF2 · C1 · cF12 · Fm-3m (225) — Strukturbericht/word 'C1' in the TDB name
- Candidate (sgte_mmc2): CaF2 · C1 · cF12 · Fm-3m (225) — Hallstedt 2025 mmc2 row for ZN3AS2_C1: Zn3As2 (ht2)
- Candidate (tdb_comment): CaF2 · cF12 · Fm-3m — ZnAs-15Gha.tdb: 'Prototype CaF2 (cF12, Fm-3m)'
- Stoichiometry: As 0.4000, Zn 0.6000
- Stability: stable in 1 of 1 calculated diagram(s): 923.97–1288.87 K, x(As) 0.4–0.4
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:as-zn:zn3as2-c1)

Names (2): _corpus: _corpus:phase:as-zn:zn3as2-c1  
_tdb: _tdb:ZnAs-15Gha.tdb:ZN3AS2_C1  


### TDB models of ZN3AS2_C1 (1): PHASE and CONSTITUENT statements as written

[ZnAs-15Gha.tdb](https://orchid-project.org/data/databases/sgte-binary/ZnAs-15Gha.tdb): ZN3AS2_C1, type code %, sha256 `6243128aa65ab792…`

~~~~text
66: PHASE ZN3AS2_C1 % 2 3 2 !
67: CONST ZN3AS2_C1 : ZN : AS : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jallcom.2015.03.051](https://doi.org/10.1016/j.jallcom.2015.03.051) Masoomeh Ghasemi, Jonas Johansson, Thermodynamic assessment of the As–Zn and As–Ga–Zn systems, Journal of Alloys and Compounds 638, 95-102 (2015).  
_assessment that models this phase_

## ZN3AS2_D59 (As–Zn)

- Id: `phase:as-zn:zn3as2-d59`; status `assigned`
- Structure: Zn3P2 · D5_9 · tP40 · P4_2/nmc (137); type `st:d5-9-zn3p2-tp40`; tier A: standard phase name; confidence high
- Stoichiometry: As 0.4000, Zn 0.6000
- Stability: stable in 1 of 1 calculated diagram(s): 462.6–923.97 K, x(As) 0.4–0.4
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:as-zn:zn3as2-d59)

Names (2): _corpus: _corpus:phase:as-zn:zn3as2-d59  
_tdb: _tdb:ZnAs-15Gha.tdb:ZN3AS2_D59  


### TDB models of ZN3AS2_D59 (1): PHASE and CONSTITUENT statements as written

[ZnAs-15Gha.tdb](https://orchid-project.org/data/databases/sgte-binary/ZnAs-15Gha.tdb): ZN3AS2_D59, type code %, sha256 `6243128aa65ab792…`

~~~~text
61: PHASE ZN3AS2_D59 % 2 3 2 !
62: CONST ZN3AS2_D59 : ZN : AS : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jallcom.2015.03.051](https://doi.org/10.1016/j.jallcom.2015.03.051) Masoomeh Ghasemi, Jonas Johansson, Thermodynamic assessment of the As–Zn and As–Ga–Zn systems, Journal of Alloys and Compounds 638, 95-102 (2015).  
_assessment that models this phase_

## ZNAS2 (As–Zn)

- Id: `phase:as-zn:znas2`; status `assigned`
- Structure: ZnAs2 · mP24 · P2_1/c (14); type `st:znas2-mp24`; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated
- Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) [doi:10.1016/j.calphad.2025.102833](https://doi.org/10.1016/j.calphad.2025.102833)
- Caveat: not certain from the name or DFT alone (no_structure_token, off_stoichiometric_model); structure as stated in the SGTE crystallographic table for this phase name and system
- Stability: stable in 1 of 1 calculated diagram(s): 300–1043.28 K, x(As) 0.66667–0.67
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:as-zn:znas2)

Names (2): _corpus: _corpus:phase:as-zn:znas2  
_tdb: _tdb:ZnAs-15Gha.tdb:ZNAS2  


### TDB models of ZNAS2 (1): PHASE and CONSTITUENT statements as written

[ZnAs-15Gha.tdb](https://orchid-project.org/data/databases/sgte-binary/ZnAs-15Gha.tdb): ZNAS2, type code %, sha256 `6243128aa65ab792…`

~~~~text
71: PHASE ZNAS2 % 2 1 2 !
72: CONST ZNAS2 : ZN% AS : AS : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jallcom.2015.03.051](https://doi.org/10.1016/j.jallcom.2015.03.051) Masoomeh Ghasemi, Jonas Johansson, Thermodynamic assessment of the As–Zn and As–Ga–Zn systems, Journal of Alloys and Compounds 638, 95-102 (2015).  
_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).