# Cu–Gd phases

> Cu–Gd system: 11 phases (tier A 6, tier C 2, liquid 1, needs_review 2); 11 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/CU-GD.html · Markdown: https://data.orchid-project.org/phases/pages/CU-GD.md

11 phases (tier A 6, tier C 2, liquid 1, needs_review 2); 11 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=CU-GD) · [full JSON](https://data.orchid-project.org/phases/systems/CU-GD.json) · [Cu–Gd system page](https://data.orchid-project.org/systems/CU-GD.html) · [Markdown](https://data.orchid-project.org/phases/pages/CU-GD.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md)

Table: Phases of the Cu–Gd system (11)

| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---:|---:|
| [BCC_A2](#phase-cu-gd-bcc-a2); _phase:cu-gd:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 872.45–2499.87 K, x(Gd) 0.8676–1 | 5 | 1 |
| [CU2GD](#phase-cu-gd-cu2gd); _phase:cu-gd:cu2gd_ | Hg2K · oI12 · Imma (74) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1124.54 K, x(Gd) 0.33333–0.33333 | 11 | 1 |
| [CU5GD_C15B](#phase-cu-gd-cu5gd-c15b); _phase:cu-gd:cu5gd-c15b_ | AuBe5 · C15_b · cF24 · F-43m (216) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–933.64 K, x(Gd) 0.16667–0.16667 | 2 | 1 |
| [CU5GD_D2D](#phase-cu-gd-cu5gd-d2d); _phase:cu-gd:cu5gd-d2d_ | CaCu5 · D2_d · hP6 · P6/mmm (191) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 933.64–1195.71 K, x(Gd) 0.16667–0.16667 | 7 | 1 |
| [CU6GD](#phase-cu-gd-cu6gd); _phase:cu-gd:cu6gd_ | CeCu6 · oP28 · Pnma (62) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1135.5 K, x(Gd) 0.14286–0.14286 | 9 | 1 |
| [CU7GD2](#phase-cu-gd-cu7gd2); _phase:cu-gd:cu7gd2_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 1104.93–1147.06 K, x(Gd) 0.22222–0.22222 | 4 | 1 |
| [CU9GD2](#phase-cu-gd-cu9gd2); _phase:cu-gd:cu9gd2_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300–1199.27 K, x(Gd) 0.18182–0.18182 | 14 | 1 |
| [CUGD_B2](#phase-cu-gd-cugd-b2); _phase:cu-gd:cugd-b2_ | CsCl · B2 · cP2 · Pm-3m (221) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1097.08 K, x(Gd) 0.5–0.5 | 10 | 1 |
| [FCC_A1](#phase-cu-gd-fcc-a1); _phase:cu-gd:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1360.77 K, x(Gd) 0–3e-05 | 3 | 1 |
| [HCP_A3](#phase-cu-gd-hcp-a3); _phase:cu-gd:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1569.02 K, x(Gd) 0.94984–1 | 2 | 1 |
| [LIQUID](#phase-cu-gd-liquid); _phase:cu-gd:liquid_ | liquid | liquid | stable in 1 of 1 calculated diagram(s): 931.34–2500 K, x(Gd) 0–1 | 28 | 1 |

## BCC_A2 (Cu–Gd)

- Id: `phase:cu-gd: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): 872.45–2499.87 K, x(Gd) 0.8676–1
- Literature: 5 values (5 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:cu-gd:bcc-a2)

Names (3): _corpus: _corpus:phase:cu-gd:bcc-a2  
_paper: _paper:10.1016/j.calphad.2009.08.003:Bcc_Gd  
_tdb: _tdb:CuGd-09Zha.tdb:BCC_A2  


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

[CuGd-09Zha.tdb](https://orchid-project.org/data/databases/sgte-binary/CuGd-09Zha.tdb): BCC_A2, type code %B, sha256 `2fc893a4bb823006…`

~~~~text
40: PHASE BCC_A2 %B 2 1 3 !
41: CONST BCC_A2 : CU GD% : VA : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2009.08.003](https://doi.org/10.1016/j.calphad.2009.08.003) L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(83)90235-7](https://doi.org/10.1016/0022-5088%2883%2990235-7) M.M. Carnasciali, S. Cirafici, E. Franceschi, On the Gd-Cu system, Journal of the Less Common Metals 92, 143-147 (1983).  
_cited as the source of values for this phase_

## CU2GD (Cu–Gd)

- Id: `phase:cu-gd:cu2gd`; status `assigned`
- Structure: Hg2K · oI12 · Imma (74); type `st:hg2k-oi12`; 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 (dft_space_group_74_matches_2_structure_types, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: Cu 0.6667, Gd 0.3333
- Stability: stable in 1 of 1 calculated diagram(s): 300–1124.54 K, x(Gd) 0.33333–0.33333
- Literature: 11 values (11 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:cu-gd:cu2gd)

Names (3): _corpus: _corpus:phase:cu-gd:cu2gd  
_paper: _paper:10.1016/j.calphad.2009.08.003:Cu2Gd  
_tdb: _tdb:CuGd-09Zha.tdb:CU2GD  


### TDB models of CU2GD (1): PHASE and CONSTITUENT statements as written

[CuGd-09Zha.tdb](https://orchid-project.org/data/databases/sgte-binary/CuGd-09Zha.tdb): CU2GD, type code %, sha256 `2fc893a4bb823006…`

~~~~text
75: PHASE CU2GD % 2 2 1 !
76: CONST CU2GD : CU : GD : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2009.08.003](https://doi.org/10.1016/j.calphad.2009.08.003) L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(83)90235-7](https://doi.org/10.1016/0022-5088%2883%2990235-7) M.M. Carnasciali, S. Cirafici, E. Franceschi, On the Gd-Cu system, Journal of the Less Common Metals 92, 143-147 (1983).  
_cited as the source of values for this phase_

## CU5GD_C15B (Cu–Gd)

- Id: `phase:cu-gd:cu5gd-c15b`; status `assigned`
- Structure: AuBe5 · C15_b · cF24 · F-43m (216); type `st:c15-b-aube5-cf24`; tier A: standard phase name; confidence high
- Stoichiometry: Cu 0.8333, Gd 0.1667
- Stability: stable in 1 of 1 calculated diagram(s): 300–933.64 K, x(Gd) 0.16667–0.16667
- Literature: 2 values (2 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:cu-gd:cu5gd-c15b)

Names (3): _corpus: _corpus:phase:cu-gd:cu5gd-c15b  
_paper: _paper:10.1016/j.calphad.2009.08.003:Cu5Gd_L  
_tdb: _tdb:CuGd-09Zha.tdb:CU5GD_C15B  


### TDB models of CU5GD_C15B (1): PHASE and CONSTITUENT statements as written

[CuGd-09Zha.tdb](https://orchid-project.org/data/databases/sgte-binary/CuGd-09Zha.tdb): CU5GD_C15B, type code %, sha256 `2fc893a4bb823006…`

~~~~text
55: PHASE CU5GD_C15B % 2 5 1 !
56: CONST CU5GD_C15B : CU : GD : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2009.08.003](https://doi.org/10.1016/j.calphad.2009.08.003) L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(83)90235-7](https://doi.org/10.1016/0022-5088%2883%2990235-7) M.M. Carnasciali, S. Cirafici, E. Franceschi, On the Gd-Cu system, Journal of the Less Common Metals 92, 143-147 (1983).  
_cited as the source of values for this phase_

## CU5GD_D2D (Cu–Gd)

- Id: `phase:cu-gd:cu5gd-d2d`; status `assigned`
- Structure: CaCu5 · D2_d · hP6 · P6/mmm (191); type `st:d2-d-cacu5-hp6`; tier A: standard phase name; confidence high
- Stoichiometry: Cu 0.8333, Gd 0.1667
- Stability: stable in 1 of 1 calculated diagram(s): 933.64–1195.71 K, x(Gd) 0.16667–0.16667
- Literature: 7 values (7 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:cu-gd:cu5gd-d2d)

Names (3): _corpus: _corpus:phase:cu-gd:cu5gd-d2d  
_paper: _paper:10.1016/j.calphad.2009.08.003:Cu5Gd_H  
_tdb: _tdb:CuGd-09Zha.tdb:CU5GD_D2D  


### TDB models of CU5GD_D2D (1): PHASE and CONSTITUENT statements as written

[CuGd-09Zha.tdb](https://orchid-project.org/data/databases/sgte-binary/CuGd-09Zha.tdb): CU5GD_D2D, type code %, sha256 `2fc893a4bb823006…`

~~~~text
60: PHASE CU5GD_D2D % 2 5 1 !
61: CONST CU5GD_D2D : CU : GD : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2009.08.003](https://doi.org/10.1016/j.calphad.2009.08.003) L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(83)90235-7](https://doi.org/10.1016/0022-5088%2883%2990235-7) M.M. Carnasciali, S. Cirafici, E. Franceschi, On the Gd-Cu system, Journal of the Less Common Metals 92, 143-147 (1983).  
_cited as the source of values for this phase_

## CU6GD (Cu–Gd)

- Id: `phase:cu-gd:cu6gd`; status `assigned`
- Structure: CeCu6 · oP28 · Pnma (62); type `st:cecu6-op28`; 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_on_hull_entry_in_both, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: Cu 0.8571, Gd 0.1429
- Stability: stable in 1 of 1 calculated diagram(s): 300–1135.5 K, x(Gd) 0.14286–0.14286
- Literature: 9 values (9 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:cu-gd:cu6gd)

Names (3): _corpus: _corpus:phase:cu-gd:cu6gd  
_paper: _paper:10.1016/j.calphad.2009.08.003:Cu6Gd  
_tdb: _tdb:CuGd-09Zha.tdb:CU6GD  


### TDB models of CU6GD (1): PHASE and CONSTITUENT statements as written

[CuGd-09Zha.tdb](https://orchid-project.org/data/databases/sgte-binary/CuGd-09Zha.tdb): CU6GD, type code %, sha256 `2fc893a4bb823006…`

~~~~text
50: PHASE CU6GD % 2 6 1 !
51: CONST CU6GD : CU : GD : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2009.08.003](https://doi.org/10.1016/j.calphad.2009.08.003) L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(83)90235-7](https://doi.org/10.1016/0022-5088%2883%2990235-7) M.M. Carnasciali, S. Cirafici, E. Franceschi, On the Gd-Cu system, Journal of the Less Common Metals 92, 143-147 (1983).  
_cited as the source of values for this phase_

## CU7GD2 (Cu–Gd)

- Id: `phase:cu-gd:cu7gd2`; status `needs_review`
- No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
- Candidate (literature_printed): (Cu7Gd2) · ? — printed with a label mapped to this phase
- Candidate (sgte_mmc2): (Cu7Gd2) — Hallstedt 2025 mmc2 row for CU7GD2: Cu7Gd2
- Stoichiometry: Cu 0.7778, Gd 0.2222
- Stability: stable in 1 of 1 calculated diagram(s): 1104.93–1147.06 K, x(Gd) 0.22222–0.22222
- Literature: 4 values (4 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:cu-gd:cu7gd2)

Names (3): _corpus: _corpus:phase:cu-gd:cu7gd2  
_paper: _paper:10.1016/j.calphad.2009.08.003:Cu7Gd2  
_tdb: _tdb:CuGd-09Zha.tdb:CU7GD2  


### TDB models of CU7GD2 (1): PHASE and CONSTITUENT statements as written

[CuGd-09Zha.tdb](https://orchid-project.org/data/databases/sgte-binary/CuGd-09Zha.tdb): CU7GD2, type code %, sha256 `2fc893a4bb823006…`

~~~~text
70: PHASE CU7GD2 % 2 7 2 !
71: CONST CU7GD2 : CU : GD : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2009.08.003](https://doi.org/10.1016/j.calphad.2009.08.003) L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(83)90235-7](https://doi.org/10.1016/0022-5088%2883%2990235-7) M.M. Carnasciali, S. Cirafici, E. Franceschi, On the Gd-Cu system, Journal of the Less Common Metals 92, 143-147 (1983).  
_cited as the source of values for this phase_

## CU9GD2 (Cu–Gd)

- Id: `phase:cu-gd:cu9gd2`; status `needs_review`
- No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
- Candidate (literature_printed): (Cu9Gd2) · ? — printed with a label mapped to this phase
- Candidate (sgte_mmc2): (Cu9Gd2) — Hallstedt 2025 mmc2 row for CU9GD2: Cu9Gd2
- Stoichiometry: Cu 0.8182, Gd 0.1818
- Stability: stable in 1 of 1 calculated diagram(s): 300–1199.27 K, x(Gd) 0.18182–0.18182
- Literature: 14 values (14 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:cu-gd:cu9gd2)

Names (3): _corpus: _corpus:phase:cu-gd:cu9gd2  
_paper: _paper:10.1016/j.calphad.2009.08.003:Cu9Gd2  
_tdb: _tdb:CuGd-09Zha.tdb:CU9GD2  


### TDB models of CU9GD2 (1): PHASE and CONSTITUENT statements as written

[CuGd-09Zha.tdb](https://orchid-project.org/data/databases/sgte-binary/CuGd-09Zha.tdb): CU9GD2, type code %, sha256 `2fc893a4bb823006…`

~~~~text
65: PHASE CU9GD2 % 2 9 2 !
66: CONST CU9GD2 : CU : GD : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2009.08.003](https://doi.org/10.1016/j.calphad.2009.08.003) L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(83)90235-7](https://doi.org/10.1016/0022-5088%2883%2990235-7) M.M. Carnasciali, S. Cirafici, E. Franceschi, On the Gd-Cu system, Journal of the Less Common Metals 92, 143-147 (1983).  
_cited as the source of values for this phase_

## CUGD_B2 (Cu–Gd)

- Id: `phase:cu-gd:cugd-b2`; status `assigned`
- Structure: CsCl · B2 · cP2 · Pm-3m (221); type `st:b2-cscl-cp2`; tier A: standard phase name; confidence high
- Stoichiometry: Cu 0.5000, Gd 0.5000
- Stability: stable in 1 of 1 calculated diagram(s): 300–1097.08 K, x(Gd) 0.5–0.5
- Literature: 10 values (10 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:cu-gd:cugd-b2)

Names (3): _corpus: _corpus:phase:cu-gd:cugd-b2  
_paper: _paper:10.1016/j.calphad.2009.08.003:CuGd  
_tdb: _tdb:CuGd-09Zha.tdb:CUGD_B2  


### TDB models of CUGD_B2 (1): PHASE and CONSTITUENT statements as written

[CuGd-09Zha.tdb](https://orchid-project.org/data/databases/sgte-binary/CuGd-09Zha.tdb): CUGD_B2, type code %, sha256 `2fc893a4bb823006…`

~~~~text
80: PHASE CUGD_B2 % 2 1 1 !
81: CONST CUGD_B2 : CU : GD : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2009.08.003](https://doi.org/10.1016/j.calphad.2009.08.003) L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(83)90235-7](https://doi.org/10.1016/0022-5088%2883%2990235-7) M.M. Carnasciali, S. Cirafici, E. Franceschi, On the Gd-Cu system, Journal of the Less Common Metals 92, 143-147 (1983).  
_cited as the source of values for this phase_

## FCC_A1 (Cu–Gd)

- Id: `phase:cu-gd: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): 300–1360.77 K, x(Gd) 0–3e-05
- Literature: 3 values (3 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:cu-gd:fcc-a1)

Names (3): _corpus: _corpus:phase:cu-gd:fcc-a1  
_paper: _paper:10.1016/j.calphad.2009.08.003:Fcc_Cu  
_tdb: _tdb:CuGd-09Zha.tdb:FCC_A1  


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

[CuGd-09Zha.tdb](https://orchid-project.org/data/databases/sgte-binary/CuGd-09Zha.tdb): FCC_A1, type code %A, sha256 `2fc893a4bb823006…`

~~~~text
35: PHASE FCC_A1 %A 2 1 1 !
36: CONST FCC_A1 : CU% GD : VA : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2009.08.003](https://doi.org/10.1016/j.calphad.2009.08.003) L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(83)90235-7](https://doi.org/10.1016/0022-5088%2883%2990235-7) M.M. Carnasciali, S. Cirafici, E. Franceschi, On the Gd-Cu system, Journal of the Less Common Metals 92, 143-147 (1983).  
_cited as the source of values for this phase_

## HCP_A3 (Cu–Gd)

- Id: `phase:cu-gd: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): 300–1569.02 K, x(Gd) 0.94984–1
- Literature: 2 values (2 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:cu-gd:hcp-a3)

Names (3): _corpus: _corpus:phase:cu-gd:hcp-a3  
_paper: _paper:10.1016/j.calphad.2009.08.003:Hcp_Gd  
_tdb: _tdb:CuGd-09Zha.tdb:HCP_A3  


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

[CuGd-09Zha.tdb](https://orchid-project.org/data/databases/sgte-binary/CuGd-09Zha.tdb): HCP_A3, type code %A, sha256 `2fc893a4bb823006…`

~~~~text
45: PHASE HCP_A3 %A 2 1 0.5 !
46: CONST HCP_A3 : CU GD% : VA : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2009.08.003](https://doi.org/10.1016/j.calphad.2009.08.003) L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(83)90235-7](https://doi.org/10.1016/0022-5088%2883%2990235-7) M.M. Carnasciali, S. Cirafici, E. Franceschi, On the Gd-Cu system, Journal of the Less Common Metals 92, 143-147 (1983).  
_cited as the source of values for this phase_

## LIQUID (Cu–Gd)

- Id: `phase:cu-gd:liquid`; status `assigned`
- Structure: liquid; type `st:liquid`; liquid; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 931.34–2500 K, x(Gd) 0–1
- Literature: 28 values (28 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:cu-gd:liquid)

Names (3): _corpus: _corpus:phase:cu-gd:liquid  
_paper: _paper:10.1016/j.calphad.2009.08.003:L  
_tdb: _tdb:CuGd-09Zha.tdb:LIQUID  


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

[CuGd-09Zha.tdb](https://orchid-project.org/data/databases/sgte-binary/CuGd-09Zha.tdb): LIQUID, type code %, sha256 `2fc893a4bb823006…`

~~~~text
30: PHASE LIQUID:L % 1 1 !
31: CONST LIQUID:L : CU GD : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2009.08.003](https://doi.org/10.1016/j.calphad.2009.08.003) L.G. Zhang, H.Q. Dong, G.X. Huang, J. Shan, L.B. Liu, Z.P. Jin, Thermodynamic assessment of the Al–Cu–Gd system, Calphad 33, 664-672 (2009).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(83)90235-7](https://doi.org/10.1016/0022-5088%2883%2990235-7) M.M. Carnasciali, S. Cirafici, E. Franceschi, On the Gd-Cu system, Journal of the Less Common Metals 92, 143-147 (1983).  
_cited as the source of values for 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).