Al–Ho phases

9 phases (tier A 5, tier B 1, tier C 2, liquid 1); 8 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 · Al–Ho system page · Markdown · field reference

Phases of the Al–Ho system (9)
Phase	Structure	Basis	Stability (calculated)	TDB models
AL2HO3 phase:al-ho:al2ho3	Al2Gd3 · tP20 · P4_2nm (102)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 2 of 2 calculated diagram(s): 300–1294.89 K, x(Ho) 0.6–0.6	2
AL3HO phase:al-ho:al3ho	Al3Ho · hR20 · R-3m (166)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 2 of 2 calculated diagram(s): 300–1365.56 K, x(Ho) 0.25–0.25	2
ALHO phase:al-ho:alho	AlDy · oP16 · Pbcm (57)	tier B: DFT-supported (unique MP + OQMD match)	stable in 2 of 2 calculated diagram(s): 300–1396.15 K, x(Ho) 0.5–0.5	2
ALHO2_C37 phase:al-ho:alho2-c37	Co2Si · C37 · oP12 · Pnma (62)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–1301.15 K, x(Ho) 0.66667–0.66667	2
BCC_A2 phase:al-ho:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	not stable in 2 calculated diagram(s)	2
C15_LAVES phase:al-ho:c15-laves	Cu2Mg · C15 · cF24 · Fd-3m (227)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–1801.83 K, x(Ho) 0.32173–0.35505	2
FCC_A1 phase:al-ho:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–937.78 K, x(Ho) 0–0	2
HCP_A3 phase:al-ho:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–2499.8 K, x(Ho) 0.99602–1	2
LIQUID phase:al-ho:liquid	liquid	liquid	stable in 2 of 2 calculated diagram(s): 902.16–2500 K, x(Ho) 0–1	2

AL2HO3 (Al–Ho)

Id: phase:al-ho:al2ho3; status assigned
Structure: Al2Gd3 · tP20 · P4_2nm (102); type st:al2gd3-tp20; 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: Al 0.4000, Ho 0.6000
Stability: stable in 2 of 2 calculated diagram(s): 300–1294.89 K, x(Ho) 0.6–0.6
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-ho:al2ho3
tdb: tdb:AlHo-03Cac-LB.tdb:AL2HO3, tdb:AlHo-13Tok.tdb:AL2HO3

TDB models of AL2HO3 (2): PHASE and CONSTITUENT statements as written

AlHo-03Cac-LB.tdb: AL2HO3, type code %, sha256 1af1b05d2b3627b3…

61: PHASE AL2HO3 % 2 2 3 !
62: CONST AL2HO3 : AL : HO : !

AlHo-13Tok.tdb: AL2HO3, type code %, sha256 c966c95b19c63dec…

61: PHASE AL2HO3 % 2 2 3 !
62: CONST AL2HO3 : AL : HO : !

Example references (2 of 2; assessments first):

doi:10.1016/S0966-9795(03)00151-1 G. Cacciamani, S. De Negri, A. Saccone, R. Ferro, Intermetallics, 11, 1135-51(2003).
assessment that models this phase
doi:10.2320/matertrans.MI201226 T. Tokunaga, H. Kominato, S. Iikubo, H. Ohtani, Mater. Trans. (JIM), 54, 647-55(2013).
assessment that models this phase

AL3HO (Al–Ho)

Id: phase:al-ho:al3ho; status assigned
Structure: Al3Ho · hR20 · R-3m (166); type st:al3ho-hr20; 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_166_matches_0_structure_types, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
Stoichiometry: Al 0.7500, Ho 0.2500
Stability: stable in 2 of 2 calculated diagram(s): 300–1365.56 K, x(Ho) 0.25–0.25
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-ho:al3ho
tdb: tdb:AlHo-03Cac-LB.tdb:AL3HO, tdb:AlHo-13Tok.tdb:AL3HO

TDB models of AL3HO (2): PHASE and CONSTITUENT statements as written

AlHo-03Cac-LB.tdb: AL3HO, type code %, sha256 1af1b05d2b3627b3…

46: PHASE AL3HO % 2 3 1 !
47: CONST AL3HO : AL : HO : !

AlHo-13Tok.tdb: AL3HO, type code %, sha256 c966c95b19c63dec…

46: PHASE AL3HO % 2 3 1 !
47: CONST AL3HO : AL : HO : !

Example references (2 of 2; assessments first):

doi:10.1016/S0966-9795(03)00151-1 G. Cacciamani, S. De Negri, A. Saccone, R. Ferro, Intermetallics, 11, 1135-51(2003).
assessment that models this phase
doi:10.2320/matertrans.MI201226 T. Tokunaga, H. Kominato, S. Iikubo, H. Ohtani, Mater. Trans. (JIM), 54, 647-55(2013).
assessment that models this phase

ALHO (Al–Ho)

Id: phase:al-ho:alho; status assigned
Structure: AlDy · oP16 · Pbcm (57); type st:aldy-op16; tier B: DFT-supported (unique MP + OQMD match); confidence high
Stoichiometry: Al 0.5000, Ho 0.5000
Stability: stable in 2 of 2 calculated diagram(s): 300–1396.15 K, x(Ho) 0.5–0.5
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:al-ho:alho
mp: mp:mp-aaacpqam
oqmd: oqmd:oqmd-690043
tdb: tdb:AlHo-03Cac-LB.tdb:ALHO, tdb:AlHo-13Tok.tdb:ALHO

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

AlHo-03Cac-LB.tdb: ALHO, type code %, sha256 1af1b05d2b3627b3…

56: PHASE ALHO % 2 1 1 !
57: CONST ALHO : AL : HO : !

AlHo-13Tok.tdb: ALHO, type code %, sha256 c966c95b19c63dec…

56: PHASE ALHO % 2 1 1 !
57: CONST ALHO : AL : HO : !

Example references (2 of 2; assessments first):

doi:10.1016/S0966-9795(03)00151-1 G. Cacciamani, S. De Negri, A. Saccone, R. Ferro, Intermetallics, 11, 1135-51(2003).
assessment that models this phase
doi:10.2320/matertrans.MI201226 T. Tokunaga, H. Kominato, S. Iikubo, H. Ohtani, Mater. Trans. (JIM), 54, 647-55(2013).
assessment that models this phase

ALHO2_C37 (Al–Ho)

Id: phase:al-ho:alho2-c37; status assigned
Structure: Co2Si · C37 · oP12 · Pnma (62); type st:c37-co2si-op12; tier A: standard phase name; confidence high
Caveat: DFT agrees: on-hull mp-aaaaayks and oqmd-10475, space group 62
Stoichiometry: Al 0.3333, Ho 0.6667
Stability: stable in 2 of 2 calculated diagram(s): 300–1301.15 K, x(Ho) 0.66667–0.66667
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:al-ho:alho2-c37
mp: mp:mp-aaaaayks
oqmd: oqmd:oqmd-10475
tdb: tdb:AlHo-03Cac-LB.tdb:ALHO2_C37, tdb:AlHo-13Tok.tdb:ALHO2_C37

TDB models of ALHO2_C37 (2): PHASE and CONSTITUENT statements as written

AlHo-03Cac-LB.tdb: ALHO2_C37, type code %, sha256 1af1b05d2b3627b3…

66: PHASE ALHO2_C37 % 2 1 2 !
67: CONST ALHO2_C37 : AL : HO : !

AlHo-13Tok.tdb: ALHO2_C37, type code %, sha256 c966c95b19c63dec…

66: PHASE ALHO2_C37 % 2 1 2 !
67: CONST ALHO2_C37 : AL : HO : !

Example references (2 of 2; assessments first):

doi:10.1016/S0966-9795(03)00151-1 G. Cacciamani, S. De Negri, A. Saccone, R. Ferro, Intermetallics, 11, 1135-51(2003).
assessment that models this phase
doi:10.2320/matertrans.MI201226 T. Tokunaga, H. Kominato, S. Iikubo, H. Ohtani, Mater. Trans. (JIM), 54, 647-55(2013).
assessment that models this phase

BCC_A2 (Al–Ho)

Id: phase:al-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: not stable in 2 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-ho:bcc-a2
tdb: tdb:AlHo-03Cac-LB.tdb:BCC_A2, tdb:AlHo-13Tok.tdb:BCC_A2

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

AlHo-03Cac-LB.tdb: BCC_A2, type code %B, sha256 1af1b05d2b3627b3…

35: PHASE BCC_A2 %B 2 1 3 !
36: CONST BCC_A2 : AL HO : VA : !

AlHo-13Tok.tdb: BCC_A2, type code %B, sha256 c966c95b19c63dec…

35: PHASE BCC_A2 %B 2 1 3 !
36: CONST BCC_A2 : AL HO : VA : !

Example references (2 of 2; assessments first):

doi:10.1016/S0966-9795(03)00151-1 G. Cacciamani, S. De Negri, A. Saccone, R. Ferro, Intermetallics, 11, 1135-51(2003).
assessment that models this phase
doi:10.2320/matertrans.MI201226 T. Tokunaga, H. Kominato, S. Iikubo, H. Ohtani, Mater. Trans. (JIM), 54, 647-55(2013).
assessment that models this phase

C15_LAVES (Al–Ho)

Id: phase:al-ho:c15-laves; status assigned
Structure: Cu2Mg · C15 · cF24 · Fd-3m (227); type st:c15-cu2mg-cf24; tier A: standard phase name; confidence high
Caveat: partitioned order/disorder model in AlHo-03Cac-LB.tdb also describes the disordered state
Caveat: partitioned order/disorder model in AlHo-13Tok.tdb also describes the disordered state
Stability: stable in 2 of 2 calculated diagram(s): 300–1801.83 K, x(Ho) 0.32173–0.35505
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-ho:c15-laves
tdb: tdb:AlHo-03Cac-LB.tdb:C15_LAVES, tdb:AlHo-13Tok.tdb:C15_LAVES

TDB models of C15_LAVES (2): PHASE and CONSTITUENT statements as written

AlHo-03Cac-LB.tdb: C15_LAVES, type code %, sha256 1af1b05d2b3627b3…

51: PHASE C15_LAVES % 2 2 1 !
52: CONST C15_LAVES : AL% HO : AL HO% : !

AlHo-13Tok.tdb: C15_LAVES, type code %, sha256 c966c95b19c63dec…

51: PHASE C15_LAVES % 2 2 1 !
52: CONST C15_LAVES : AL% HO : AL HO% : !

Example references (2 of 2; assessments first):

doi:10.1016/S0966-9795(03)00151-1 G. Cacciamani, S. De Negri, A. Saccone, R. Ferro, Intermetallics, 11, 1135-51(2003).
assessment that models this phase
doi:10.2320/matertrans.MI201226 T. Tokunaga, H. Kominato, S. Iikubo, H. Ohtani, Mater. Trans. (JIM), 54, 647-55(2013).
assessment that models this phase

FCC_A1 (Al–Ho)

Id: phase:al-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): 300–937.78 K, x(Ho) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-ho:fcc-a1
tdb: tdb:AlHo-03Cac-LB.tdb:FCC_A1, tdb:AlHo-13Tok.tdb:FCC_A1

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

AlHo-03Cac-LB.tdb: FCC_A1, type code %A, sha256 1af1b05d2b3627b3…

30: PHASE FCC_A1 %A 2 1 1 !
31: CONST FCC_A1 : AL% HO : VA : !

AlHo-13Tok.tdb: FCC_A1, type code %A, sha256 c966c95b19c63dec…

30: PHASE FCC_A1 %A 2 1 1 !
31: CONST FCC_A1 : AL% HO : VA : !

Example references (2 of 2; assessments first):

doi:10.1016/S0966-9795(03)00151-1 G. Cacciamani, S. De Negri, A. Saccone, R. Ferro, Intermetallics, 11, 1135-51(2003).
assessment that models this phase
doi:10.2320/matertrans.MI201226 T. Tokunaga, H. Kominato, S. Iikubo, H. Ohtani, Mater. Trans. (JIM), 54, 647-55(2013).
assessment that models this phase

HCP_A3 (Al–Ho)

Id: phase:al-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): 300–2499.8 K, x(Ho) 0.99602–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-ho:hcp-a3
tdb: tdb:AlHo-03Cac-LB.tdb:HCP_A3, tdb:AlHo-13Tok.tdb:HCP_A3

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

AlHo-03Cac-LB.tdb: HCP_A3, type code %A, sha256 1af1b05d2b3627b3…

40: PHASE HCP_A3 %A 2 1 0.5 !
41: CONST HCP_A3 : AL HO% : VA : !

AlHo-13Tok.tdb: HCP_A3, type code %A, sha256 c966c95b19c63dec…

40: PHASE HCP_A3 %A 2 1 0.5 !
41: CONST HCP_A3 : AL HO% : VA : !

Example references (2 of 2; assessments first):

doi:10.1016/S0966-9795(03)00151-1 G. Cacciamani, S. De Negri, A. Saccone, R. Ferro, Intermetallics, 11, 1135-51(2003).
assessment that models this phase
doi:10.2320/matertrans.MI201226 T. Tokunaga, H. Kominato, S. Iikubo, H. Ohtani, Mater. Trans. (JIM), 54, 647-55(2013).
assessment that models this phase

LIQUID (Al–Ho)

Id: phase:al-ho:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 902.16–2500 K, x(Ho) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-ho:liquid
tdb: tdb:AlHo-03Cac-LB.tdb:LIQUID, tdb:AlHo-13Tok.tdb:LIQUID

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

AlHo-03Cac-LB.tdb: LIQUID, type code %, sha256 1af1b05d2b3627b3…

25: PHASE LIQUID:L % 1 1 !
26: CONST LIQUID:L : AL HO : !

AlHo-13Tok.tdb: LIQUID, type code %, sha256 c966c95b19c63dec…

25: PHASE LIQUID:L % 1 1 !
26: CONST LIQUID:L : AL HO : !

Example references (2 of 2; assessments first):

doi:10.1016/S0966-9795(03)00151-1 G. Cacciamani, S. De Negri, A. Saccone, R. Ferro, Intermetallics, 11, 1135-51(2003).
assessment that models this phase
doi:10.2320/matertrans.MI201226 T. Tokunaga, H. Kominato, S. Iikubo, H. Ohtani, Mater. Trans. (JIM), 54, 647-55(2013).
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). 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}
}