Cu–Ho phases

10 phases (tier A 6, tier C 1, liquid 1, needs_review 2); 10 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–Ho system page · Markdown · field reference

Phases of the Cu–Ho system (10)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
BCC_A2 phase:cu-ho:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 2 calculated diagram(s): 1700.91–2499.66 K, x(Ho) 0.99955–1	0	2
CU2HO phase:cu-ho:cu2ho	Hg2K · oI12 · Imma (74)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 2 of 2 calculated diagram(s): 300–1161.14 K, x(Ho) 0.33333–0.33333	6	2
CU5HO_C15B phase:cu-ho:cu5ho-c15b	AuBe5 · C15_b · cF24 · F-43m (216)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–1242.86 K, x(Ho) 0.16667–0.16667	5	2
CU5HO_D2D phase:cu-ho:cu5ho-d2d	CaCu5 · D2_d · hP6 · P6/mmm (191)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 1242.86–1259.36 K, x(Ho) 0.16667–0.16667	4	2
CU7HO2 phase:cu-ho:cu7ho2		needs_review	stable in 2 of 2 calculated diagram(s): 1143.81–1206.65 K, x(Ho) 0.22222–0.22222	4	2
CU9HO2 phase:cu-ho:cu9ho2		needs_review	stable in 2 of 2 calculated diagram(s): 300–1262.98 K, x(Ho) 0.18182–0.18182	10	2
CUHO_B2 phase:cu-ho:cuho-b2	CsCl · B2 · cP2 · Pm-3m (221)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–1285.55 K, x(Ho) 0.5–0.5	6	2
FCC_A1 phase:cu-ho:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–1374.2 K, x(Ho) 0–0	3	2
HCP_A3 phase:cu-ho:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–2499.14 K, x(Ho) 0.99953–1	2	2
LIQUID phase:cu-ho:liquid	liquid	liquid	stable in 2 of 2 calculated diagram(s): 1103.13–2500 K, x(Ho) 0–1	21	2

BCC_A2 (Cu–Ho)

Id: phase:cu-ho: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 2 calculated diagram(s): 1700.91–2499.66 K, x(Ho) 0.99955–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:cu-ho:bcc-a2
tdb: tdb:CuHo-09Wan-newHo.tdb:BCC_A2, tdb:CuHo-09Wan.tdb:BCC_A2

TDB models of BCC_A2 (2): PHASE and CONSTITUENT statements as written

CuHo-09Wan-newHo.tdb: BCC_A2, type code %B, sha256 b376cb3e339bac72…

36: PHASE BCC_A2 %B 2 1 3 !
37: CONST BCC_A2 : CU HO : VA : !

CuHo-09Wan.tdb: BCC_A2, type code %B, sha256 7fa1a2bcc060b66d…

36: PHASE BCC_A2 %B 2 1 3 !
37: CONST BCC_A2 : CU HO : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2009.08.042 C.P. Wang, S.H. Guo, X.J. Liu, A.T. Tang, F.S. Pan, Thermodynamic assessments of the Ho–X (X: Cu, Mo, V) systems, Journal of Alloys and Compounds 487, 173-178 (2009).
assessment that models this phase

CU2HO (Cu–Ho)

Id: phase:cu-ho:cu2ho; 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, Ho 0.3333
Stability: stable in 2 of 2 calculated diagram(s): 300–1161.14 K, x(Ho) 0.33333–0.33333
Literature: 6 values (6 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-ho:cu2ho
paper: paper:10.1016/j.jallcom.2009.08.042:Cu2Ho
tdb: tdb:CuHo-09Wan-newHo.tdb:CU2HO, tdb:CuHo-09Wan.tdb:CU2HO

TDB models of CU2HO (2): PHASE and CONSTITUENT statements as written

CuHo-09Wan-newHo.tdb: CU2HO, type code %, sha256 b376cb3e339bac72…

66: PHASE CU2HO % 2 2 1 !
67: CONST CU2HO : CU : HO : !

CuHo-09Wan.tdb: CU2HO, type code %, sha256 7fa1a2bcc060b66d…

66: PHASE CU2HO % 2 2 1 !
67: CONST CU2HO : CU : HO : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2009.08.042 C.P. Wang, S.H. Guo, X.J. Liu, A.T. Tang, F.S. Pan, Thermodynamic assessments of the Ho–X (X: Cu, Mo, V) systems, Journal of Alloys and Compounds 487, 173-178 (2009).
assessment that models this phase; reports values for this phase

CU5HO_C15B (Cu–Ho)

Id: phase:cu-ho:cu5ho-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, Ho 0.1667
Stability: stable in 2 of 2 calculated diagram(s): 300–1242.86 K, x(Ho) 0.16667–0.16667
Literature: 5 values (5 accepted) from 1 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:cu-ho:cu5ho-c15b
paper: paper:10.1016/j.jallcom.2009.08.042:Cu5Ho, paper:10.1016/j.jallcom.2009.08.042:αCu5Ho
tdb: tdb:CuHo-09Wan-newHo.tdb:CU5HO_C15B, tdb:CuHo-09Wan.tdb:CU5HO_C15B

TDB models of CU5HO_C15B (2): PHASE and CONSTITUENT statements as written

CuHo-09Wan-newHo.tdb: CU5HO_C15B, type code %, sha256 b376cb3e339bac72…

46: PHASE CU5HO_C15B % 2 5 1 !
47: CONST CU5HO_C15B : CU : HO : !

CuHo-09Wan.tdb: CU5HO_C15B, type code %, sha256 7fa1a2bcc060b66d…

46: PHASE CU5HO_C15B % 2 5 1 !
47: CONST CU5HO_C15B : CU : HO : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2009.08.042 C.P. Wang, S.H. Guo, X.J. Liu, A.T. Tang, F.S. Pan, Thermodynamic assessments of the Ho–X (X: Cu, Mo, V) systems, Journal of Alloys and Compounds 487, 173-178 (2009).
assessment that models this phase; reports values for this phase

CU5HO_D2D (Cu–Ho)

Id: phase:cu-ho:cu5ho-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, Ho 0.1667
Stability: stable in 2 of 2 calculated diagram(s): 1242.86–1259.36 K, x(Ho) 0.16667–0.16667
Literature: 4 values (4 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-ho:cu5ho-d2d
paper: paper:10.1016/j.jallcom.2009.08.042:βCu5Ho
tdb: tdb:CuHo-09Wan-newHo.tdb:CU5HO_D2D, tdb:CuHo-09Wan.tdb:CU5HO_D2D

TDB models of CU5HO_D2D (2): PHASE and CONSTITUENT statements as written

CuHo-09Wan-newHo.tdb: CU5HO_D2D, type code %, sha256 b376cb3e339bac72…

51: PHASE CU5HO_D2D % 2 5 1 !
52: CONST CU5HO_D2D : CU : HO : !

CuHo-09Wan.tdb: CU5HO_D2D, type code %, sha256 7fa1a2bcc060b66d…

51: PHASE CU5HO_D2D % 2 5 1 !
52: CONST CU5HO_D2D : CU : HO : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2009.08.042 C.P. Wang, S.H. Guo, X.J. Liu, A.T. Tang, F.S. Pan, Thermodynamic assessments of the Ho–X (X: Cu, Mo, V) systems, Journal of Alloys and Compounds 487, 173-178 (2009).
assessment that models this phase; reports values for this phase

CU7HO2 (Cu–Ho)

Id: phase:cu-ho:cu7ho2; status needs_review
No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
Candidate (literature_printed): (Cu7Ho2) · ? — printed with a label mapped to this phase
Candidate (sgte_mmc2): (Cu7Ho2) — Hallstedt 2025 mmc2 row for CU7HO2: Cu7Ho2
Stoichiometry: Cu 0.7778, Ho 0.2222
Stability: stable in 2 of 2 calculated diagram(s): 1143.81–1206.65 K, x(Ho) 0.22222–0.22222
Literature: 4 values (4 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-ho:cu7ho2
paper: paper:10.1016/j.jallcom.2009.08.042:Cu7Ho2
tdb: tdb:CuHo-09Wan-newHo.tdb:CU7HO2, tdb:CuHo-09Wan.tdb:CU7HO2

TDB models of CU7HO2 (2): PHASE and CONSTITUENT statements as written

CuHo-09Wan-newHo.tdb: CU7HO2, type code %, sha256 b376cb3e339bac72…

61: PHASE CU7HO2 % 2 7 2 !
62: CONST CU7HO2 : CU : HO : !

CuHo-09Wan.tdb: CU7HO2, type code %, sha256 7fa1a2bcc060b66d…

61: PHASE CU7HO2 % 2 7 2 !
62: CONST CU7HO2 : CU : HO : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2009.08.042 C.P. Wang, S.H. Guo, X.J. Liu, A.T. Tang, F.S. Pan, Thermodynamic assessments of the Ho–X (X: Cu, Mo, V) systems, Journal of Alloys and Compounds 487, 173-178 (2009).
assessment that models this phase; reports values for this phase

CU9HO2 (Cu–Ho)

Id: phase:cu-ho:cu9ho2; status needs_review
No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
Candidate (literature_printed): (Cu9Ho2) · ? — printed with a label mapped to this phase
Candidate (sgte_mmc2): (Cu9Ho2) — Hallstedt 2025 mmc2 row for CU9HO2: Cu9Ho2
Stoichiometry: Cu 0.8182, Ho 0.1818
Stability: stable in 2 of 2 calculated diagram(s): 300–1262.98 K, x(Ho) 0.18182–0.18182
Literature: 10 values (10 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-ho:cu9ho2
paper: paper:10.1016/j.jallcom.2009.08.042:Cu9Ho2
tdb: tdb:CuHo-09Wan-newHo.tdb:CU9HO2, tdb:CuHo-09Wan.tdb:CU9HO2

TDB models of CU9HO2 (2): PHASE and CONSTITUENT statements as written

CuHo-09Wan-newHo.tdb: CU9HO2, type code %, sha256 b376cb3e339bac72…

56: PHASE CU9HO2 % 2 9 2 !
57: CONST CU9HO2 : CU : HO : !

CuHo-09Wan.tdb: CU9HO2, type code %, sha256 7fa1a2bcc060b66d…

56: PHASE CU9HO2 % 2 9 2 !
57: CONST CU9HO2 : CU : HO : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2009.08.042 C.P. Wang, S.H. Guo, X.J. Liu, A.T. Tang, F.S. Pan, Thermodynamic assessments of the Ho–X (X: Cu, Mo, V) systems, Journal of Alloys and Compounds 487, 173-178 (2009).
assessment that models this phase; reports values for this phase

CUHO_B2 (Cu–Ho)

Id: phase:cu-ho:cuho-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, Ho 0.5000
Stability: stable in 2 of 2 calculated diagram(s): 300–1285.55 K, x(Ho) 0.5–0.5
Literature: 6 values (6 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-ho:cuho-b2
paper: paper:10.1016/j.jallcom.2009.08.042:CuHo
tdb: tdb:CuHo-09Wan-newHo.tdb:CUHO_B2, tdb:CuHo-09Wan.tdb:CUHO_B2

TDB models of CUHO_B2 (2): PHASE and CONSTITUENT statements as written

CuHo-09Wan-newHo.tdb: CUHO_B2, type code %, sha256 b376cb3e339bac72…

71: PHASE CUHO_B2 % 2 1 1 !
72: CONST CUHO_B2 : CU : HO : !

CuHo-09Wan.tdb: CUHO_B2, type code %, sha256 7fa1a2bcc060b66d…

71: PHASE CUHO_B2 % 2 1 1 !
72: CONST CUHO_B2 : CU : HO : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2009.08.042 C.P. Wang, S.H. Guo, X.J. Liu, A.T. Tang, F.S. Pan, Thermodynamic assessments of the Ho–X (X: Cu, Mo, V) systems, Journal of Alloys and Compounds 487, 173-178 (2009).
assessment that models this phase; reports values for this phase

FCC_A1 (Cu–Ho)

Id: phase:cu-ho: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 2 of 2 calculated diagram(s): 300–1374.2 K, x(Ho) 0–0
Literature: 3 values (3 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-ho:fcc-a1
paper: paper:10.1016/j.jallcom.2009.08.042:(Cu)
tdb: tdb:CuHo-09Wan-newHo.tdb:FCC_A1, tdb:CuHo-09Wan.tdb:FCC_A1

TDB models of FCC_A1 (2): PHASE and CONSTITUENT statements as written

CuHo-09Wan-newHo.tdb: FCC_A1, type code %A, sha256 b376cb3e339bac72…

31: PHASE FCC_A1 %A 2 1 1 !
32: CONST FCC_A1 : CU% HO : VA : !

CuHo-09Wan.tdb: FCC_A1, type code %A, sha256 7fa1a2bcc060b66d…

31: PHASE FCC_A1 %A 2 1 1 !
32: CONST FCC_A1 : CU% HO : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2009.08.042 C.P. Wang, S.H. Guo, X.J. Liu, A.T. Tang, F.S. Pan, Thermodynamic assessments of the Ho–X (X: Cu, Mo, V) systems, Journal of Alloys and Compounds 487, 173-178 (2009).
assessment that models this phase; reports values for this phase

HCP_A3 (Cu–Ho)

Id: phase:cu-ho: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 2 of 2 calculated diagram(s): 300–2499.14 K, x(Ho) 0.99953–1
Literature: 2 values (2 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-ho:hcp-a3
paper: paper:10.1016/j.jallcom.2009.08.042:(Ho)
tdb: tdb:CuHo-09Wan-newHo.tdb:HCP_A3, tdb:CuHo-09Wan.tdb:HCP_A3

TDB models of HCP_A3 (2): PHASE and CONSTITUENT statements as written

CuHo-09Wan-newHo.tdb: HCP_A3, type code %A, sha256 b376cb3e339bac72…

41: PHASE HCP_A3 %A 2 1 0.5 !
42: CONST HCP_A3 : CU HO% : VA : !

CuHo-09Wan.tdb: HCP_A3, type code %A, sha256 7fa1a2bcc060b66d…

41: PHASE HCP_A3 %A 2 1 0.5 !
42: CONST HCP_A3 : CU HO% : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2009.08.042 C.P. Wang, S.H. Guo, X.J. Liu, A.T. Tang, F.S. Pan, Thermodynamic assessments of the Ho–X (X: Cu, Mo, V) systems, Journal of Alloys and Compounds 487, 173-178 (2009).
assessment that models this phase; reports values for this phase

LIQUID (Cu–Ho)

Id: phase:cu-ho:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 1103.13–2500 K, x(Ho) 0–1
Literature: 21 values (21 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-ho:liquid
paper: paper:10.1016/j.jallcom.2009.08.042:L
tdb: tdb:CuHo-09Wan-newHo.tdb:LIQUID, tdb:CuHo-09Wan.tdb:LIQUID

TDB models of LIQUID (2): PHASE and CONSTITUENT statements as written

CuHo-09Wan-newHo.tdb: LIQUID, type code %, sha256 b376cb3e339bac72…

26: PHASE LIQUID:L % 1 1 !
27: CONST LIQUID:L : CU HO : !

CuHo-09Wan.tdb: LIQUID, type code %, sha256 7fa1a2bcc060b66d…

26: PHASE LIQUID:L % 1 1 !
27: CONST LIQUID:L : CU HO : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2009.08.042 C.P. Wang, S.H. Guo, X.J. Liu, A.T. Tang, F.S. Pan, Thermodynamic assessments of the Ho–X (X: Cu, Mo, V) systems, Journal of Alloys and Compounds 487, 173-178 (2009).
assessment that models this phase; reports 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}
}