# Ge–Ta phases

> Ge–Ta system: 9 phases (tier A 7, tier C 1, liquid 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/GE-TA.html · Markdown: https://data.orchid-project.org/phases/pages/GE-TA.md

9 phases (tier A 7, tier C 1, liquid 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=GE-TA) · [full JSON](https://data.orchid-project.org/phases/systems/GE-TA.json) · [Ge–Ta system page](https://data.orchid-project.org/systems/GE-TA.html) · [Markdown](https://data.orchid-project.org/phases/pages/GE-TA.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md)

Table: Phases of the Ge–Ta system (9)

| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---:|---:|
| [DIAMOND_A4](#phase-ge-ta-a4-diamond); _phase:ge-ta:a4-diamond_ | C (diamond) · A4 · cF8 · Fd-3m (227) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1211.4 K, x(Ta) 0–0.00161 | 0 | 1 |
| [BCC_A2](#phase-ge-ta-bcc-a2); _phase:ge-ta:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–3999.98 K, x(Ta) 0.89938–1 | 0 | 1 |
| [FCC_A1](#phase-ge-ta-fcc-a1); _phase:ge-ta:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | not stable in 1 calculated diagram(s) | 0 | 1 |
| [GE2TA_C40](#phase-ge-ta-ge2ta-c40); _phase:ge-ta:ge2ta-c40_ | CrSi2 · C40 · hP9 · P6_222 (180) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–2220.11 K, x(Ta) 0.33333–0.33333 | 0 | 1 |
| [GE3TA5_D8M](#phase-ge-ta-ge3ta5-d8m); _phase:ge-ta:ge3ta5-d8m_ | W5Si3 · D8_m · tI32 · I4/mcm (140) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–2844.89 K, x(Ta) 0.625–0.625 | 0 | 1 |
| [GETA3_ALPHA](#phase-ge-ta-geta3-alpha); _phase:ge-ta:geta3-alpha_ | Ti3P · tP32 · P4_2/n (86) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1823.13 K, x(Ta) 0.75–0.75 | 0 | 1 |
| [GETA3_D0E](#phase-ge-ta-geta3-d0e); _phase:ge-ta:geta3-d0e_ | Ni3P · D0_e · tI32 · I-4 (82) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 1823.13–2788.79 K, x(Ta) 0.75–0.75 | 0 | 1 |
| [HCP_A3](#phase-ge-ta-hcp-a3); _phase:ge-ta:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | not stable in 1 calculated diagram(s) | 0 | 1 |
| [LIQUID](#phase-ge-ta-liquid); _phase:ge-ta:liquid_ | liquid | liquid | stable in 1 of 1 calculated diagram(s): 1204.63–4000 K, x(Ta) 0–1 | 0 | 1 |

## DIAMOND_A4 (Ge–Ta)

- Id: `phase:ge-ta:a4-diamond`; status `assigned`
- Structure: C (diamond) · A4 · cF8 · Fd-3m (227); type `st:a4-c-diamond-cf8`; tier A: standard phase name; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 300–1211.4 K, x(Ta) 0–0.00161
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ge-ta:a4-diamond)

Names (2): _corpus: _corpus:phase:ge-ta:a4-diamond  
_tdb: _tdb:GeTa-24Pin.tdb:DIAMOND_A4  


### TDB models of DIAMOND_A4 (1): PHASE and CONSTITUENT statements as written

[GeTa-24Pin.tdb](https://orchid-project.org/data/databases/sgte-binary/GeTa-24Pin.tdb): DIAMOND_A4, type code %, sha256 `17e38d477bb8cded…`

~~~~text
45: PHASE DIAMOND_A4 % 1 1 !
46: CONST DIAMOND_A4 : GE% TA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2024.102669](https://doi.org/10.1016/j.calphad.2024.102669) A.A.A. Pinto da Silva, P.P. Ferreira, T.T. Dorini, G.C. Coelho, C.A. Nunes, L.T.F. Eleno, Calphad, 84, 102669(2024).  
_assessment that models this phase_

## BCC_A2 (Ge–Ta)

- Id: `phase:ge-ta: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): 300–3999.98 K, x(Ta) 0.89938–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ge-ta:bcc-a2)

Names (2): _corpus: _corpus:phase:ge-ta:bcc-a2  
_tdb: _tdb:GeTa-24Pin.tdb:BCC_A2  


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

[GeTa-24Pin.tdb](https://orchid-project.org/data/databases/sgte-binary/GeTa-24Pin.tdb): BCC_A2, type code %B, sha256 `17e38d477bb8cded…`

~~~~text
35: PHASE BCC_A2 %B 2 1 3 !
36: CONST BCC_A2 : GE TA% : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2024.102669](https://doi.org/10.1016/j.calphad.2024.102669) A.A.A. Pinto da Silva, P.P. Ferreira, T.T. Dorini, G.C. Coelho, C.A. Nunes, L.T.F. Eleno, Calphad, 84, 102669(2024).  
_assessment that models this phase_

## FCC_A1 (Ge–Ta)

- Id: `phase:ge-ta: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:ge-ta:fcc-a1)

Names (2): _corpus: _corpus:phase:ge-ta:fcc-a1  
_tdb: _tdb:GeTa-24Pin.tdb:FCC_A1  


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

[GeTa-24Pin.tdb](https://orchid-project.org/data/databases/sgte-binary/GeTa-24Pin.tdb): FCC_A1, type code %A, sha256 `17e38d477bb8cded…`

~~~~text
30: PHASE FCC_A1 %A 2 1 1 !
31: CONST FCC_A1 : GE TA : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2024.102669](https://doi.org/10.1016/j.calphad.2024.102669) A.A.A. Pinto da Silva, P.P. Ferreira, T.T. Dorini, G.C. Coelho, C.A. Nunes, L.T.F. Eleno, Calphad, 84, 102669(2024).  
_assessment that models this phase_

## GE2TA_C40 (Ge–Ta)

- Id: `phase:ge-ta:ge2ta-c40`; status `assigned`
- Structure: CrSi2 · C40 · hP9 · P6_222 (180); type `st:c40-crsi2-hp9`; tier A: standard phase name; confidence high
- Caveat: DFT agrees: on-hull mp-aaaaales and oqmd-667417, space group 180
- Stoichiometry: Ge 0.6667, Ta 0.3333
- Stability: stable in 1 of 1 calculated diagram(s): 300–2220.11 K, x(Ta) 0.33333–0.33333
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ge-ta:ge2ta-c40)

Names (4): _corpus: _corpus:phase:ge-ta:ge2ta-c40  
_mp: _mp:mp-aaaaales  
_oqmd: _oqmd:oqmd-667417  
_tdb: _tdb:GeTa-24Pin.tdb:GE2TA_C40  


### TDB models of GE2TA_C40 (1): PHASE and CONSTITUENT statements as written

[GeTa-24Pin.tdb](https://orchid-project.org/data/databases/sgte-binary/GeTa-24Pin.tdb): GE2TA_C40, type code %, sha256 `17e38d477bb8cded…`

~~~~text
50: PHASE GE2TA_C40 % 2 2 1 !
51: CONST GE2TA_C40 : GE : TA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2024.102669](https://doi.org/10.1016/j.calphad.2024.102669) A.A.A. Pinto da Silva, P.P. Ferreira, T.T. Dorini, G.C. Coelho, C.A. Nunes, L.T.F. Eleno, Calphad, 84, 102669(2024).  
_assessment that models this phase_

## GE3TA5_D8M (Ge–Ta)

- Id: `phase:ge-ta:ge3ta5-d8m`; status `assigned`
- Structure: W5Si3 · D8_m · tI32 · I4/mcm (140); type `st:d8-m-w5si3-ti32`; tier A: standard phase name; confidence high
- Caveat: DFT agrees: on-hull mp-aaaabaar and oqmd-48717, space group 140
- Stoichiometry: Ge 0.3750, Ta 0.6250
- Stability: stable in 1 of 1 calculated diagram(s): 300–2844.89 K, x(Ta) 0.625–0.625
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ge-ta:ge3ta5-d8m)

Names (4): _corpus: _corpus:phase:ge-ta:ge3ta5-d8m  
_mp: _mp:mp-aaaabaar  
_oqmd: _oqmd:oqmd-48717  
_tdb: _tdb:GeTa-24Pin.tdb:GE3TA5_D8M  


### TDB models of GE3TA5_D8M (1): PHASE and CONSTITUENT statements as written

[GeTa-24Pin.tdb](https://orchid-project.org/data/databases/sgte-binary/GeTa-24Pin.tdb): GE3TA5_D8M, type code %, sha256 `17e38d477bb8cded…`

~~~~text
55: PHASE GE3TA5_D8M % 2 3 5 !
56: CONST GE3TA5_D8M : GE : TA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2024.102669](https://doi.org/10.1016/j.calphad.2024.102669) A.A.A. Pinto da Silva, P.P. Ferreira, T.T. Dorini, G.C. Coelho, C.A. Nunes, L.T.F. Eleno, Calphad, 84, 102669(2024).  
_assessment that models this phase_

## GETA3_ALPHA (Ge–Ta)

- Id: `phase:ge-ta:geta3-alpha`; status `assigned`
- Structure: Ti3P · tP32 · P4_2/n (86); type `st:ti3p-tp32`; 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: Ge 0.2500, Ta 0.7500
- Stability: stable in 1 of 1 calculated diagram(s): 300–1823.13 K, x(Ta) 0.75–0.75
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ge-ta:geta3-alpha)

Names (2): _corpus: _corpus:phase:ge-ta:geta3-alpha  
_tdb: _tdb:GeTa-24Pin.tdb:GETA3_ALPHA  


### TDB models of GETA3_ALPHA (1): PHASE and CONSTITUENT statements as written

[GeTa-24Pin.tdb](https://orchid-project.org/data/databases/sgte-binary/GeTa-24Pin.tdb): GETA3_ALPHA, type code %, sha256 `17e38d477bb8cded…`

~~~~text
60: PHASE GETA3_ALPHA % 2 1 3 !
61: CONST GETA3_ALPHA : GE : TA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2024.102669](https://doi.org/10.1016/j.calphad.2024.102669) A.A.A. Pinto da Silva, P.P. Ferreira, T.T. Dorini, G.C. Coelho, C.A. Nunes, L.T.F. Eleno, Calphad, 84, 102669(2024).  
_assessment that models this phase_

## GETA3_D0E (Ge–Ta)

- Id: `phase:ge-ta:geta3-d0e`; status `assigned`
- Structure: Ni3P · D0_e · tI32 · I-4 (82); type `st:d0-e-ni3p-ti32`; tier A: standard phase name; confidence high
- Stoichiometry: Ge 0.2500, Ta 0.7500
- Stability: stable in 1 of 1 calculated diagram(s): 1823.13–2788.79 K, x(Ta) 0.75–0.75
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ge-ta:geta3-d0e)

Names (2): _corpus: _corpus:phase:ge-ta:geta3-d0e  
_tdb: _tdb:GeTa-24Pin.tdb:GETA3_D0E  


### TDB models of GETA3_D0E (1): PHASE and CONSTITUENT statements as written

[GeTa-24Pin.tdb](https://orchid-project.org/data/databases/sgte-binary/GeTa-24Pin.tdb): GETA3_D0E, type code %, sha256 `17e38d477bb8cded…`

~~~~text
65: PHASE GETA3_D0E % 2 1 3 !
66: CONST GETA3_D0E : GE : TA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2024.102669](https://doi.org/10.1016/j.calphad.2024.102669) A.A.A. Pinto da Silva, P.P. Ferreira, T.T. Dorini, G.C. Coelho, C.A. Nunes, L.T.F. Eleno, Calphad, 84, 102669(2024).  
_assessment that models this phase_

## HCP_A3 (Ge–Ta)

- Id: `phase:ge-ta: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:ge-ta:hcp-a3)

Names (2): _corpus: _corpus:phase:ge-ta:hcp-a3  
_tdb: _tdb:GeTa-24Pin.tdb:HCP_A3  


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

[GeTa-24Pin.tdb](https://orchid-project.org/data/databases/sgte-binary/GeTa-24Pin.tdb): HCP_A3, type code %A, sha256 `17e38d477bb8cded…`

~~~~text
40: PHASE HCP_A3 %A 2 1 0.5 !
41: CONST HCP_A3 : GE TA : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2024.102669](https://doi.org/10.1016/j.calphad.2024.102669) A.A.A. Pinto da Silva, P.P. Ferreira, T.T. Dorini, G.C. Coelho, C.A. Nunes, L.T.F. Eleno, Calphad, 84, 102669(2024).  
_assessment that models this phase_

## LIQUID (Ge–Ta)

- Id: `phase:ge-ta:liquid`; status `assigned`
- Structure: liquid; type `st:liquid`; liquid; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 1204.63–4000 K, x(Ta) 0–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:ge-ta:liquid)

Names (2): _corpus: _corpus:phase:ge-ta:liquid  
_tdb: _tdb:GeTa-24Pin.tdb:LIQUID  


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

[GeTa-24Pin.tdb](https://orchid-project.org/data/databases/sgte-binary/GeTa-24Pin.tdb): LIQUID, type code %, sha256 `17e38d477bb8cded…`

~~~~text
25: PHASE LIQUID:L % 1 1 !
26: CONST LIQUID:L : GE TA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2024.102669](https://doi.org/10.1016/j.calphad.2024.102669) A.A.A. Pinto da Silva, P.P. Ferreira, T.T. Dorini, G.C. Coelho, C.A. Nunes, L.T.F. Eleno, Calphad, 84, 102669(2024).  
_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).