Cu–Gd phases

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 · full JSON · Cu–Gd system page · Markdown · field reference

Phases of the Cu–Gd system (11)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
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	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	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	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	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		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		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	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	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	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	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

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: BCC_A2, type code %B, sha256 2fc893a4bb823006…

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 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 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
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

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: CU2GD, type code %, sha256 2fc893a4bb823006…

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 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 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

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: CU5GD_C15B, type code %, sha256 2fc893a4bb823006…

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 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 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

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: CU5GD_D2D, type code %, sha256 2fc893a4bb823006…

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 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 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
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

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: CU6GD, type code %, sha256 2fc893a4bb823006…

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 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 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

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: CU7GD2, type code %, sha256 2fc893a4bb823006…

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 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 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

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: CU9GD2, type code %, sha256 2fc893a4bb823006…

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 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 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

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: CUGD_B2, type code %, sha256 2fc893a4bb823006…

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 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 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

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: FCC_A1, type code %A, sha256 2fc893a4bb823006…

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 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 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

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: HCP_A3, type code %A, sha256 2fc893a4bb823006…

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 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 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

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: LIQUID, type code %, sha256 2fc893a4bb823006…

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 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 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). doi: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). doi: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.

@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}
}