Hf–Pt phases

11 phases (tier A 6, tier C 3, liquid 1, needs_review 1); 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 · Hf–Pt system page · Markdown · field reference

Phases of the Hf–Pt system (11)
Phase	Structure	Basis	Stability (calculated)	TDB models
BCC_A2 phase:hf-pt:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 1660–2517.83 K, x(Pt) 0–0.09811	2
B2_BCC phase:hf-pt:bcc-b2	CsCl · B2 · cP2 · Pm-3m (221)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 1652.71–2517.98 K, x(Pt) 0–0.50186	1
FCC_A1 phase:hf-pt:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–2183.35 K, x(Pt) 0.8398–1	1
HCP_A3 phase:hf-pt:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 890–1900 K	2
D024_HCP phase:hf-pt:hcp-d024		needs_review	stable in 1 of 1 calculated diagram(s): 300–2522.04 K, x(Pt) 0–0.75	1
HF2PT phase:hf-pt:hf2pt	NiTi2 · cF96 · Fd-3m (227)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–1933.11 K, x(Pt) 0.31463–0.33333	1
HF2PT3 phase:hf-pt:hf2pt3	Pd3Ti2 · oC20 · Cmcm (63)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–1960 K, x(Pt) 0.6–0.6	1
HF3PT4 phase:hf-pt:hf3pt4	Pd4Pu3 · hR14 · R-3 (148)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–2373.26 K, x(Pt) 0.53505–0.57118	1
HFPT_B33 phase:hf-pt:hfpt-b33	CrB · B33 · oC8 · Cmcm (63)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1960 K, x(Pt) 0.46335–0.5	1
HFPT4_L12 phase:hf-pt:hfpt4-l12	AuCu3 · L1_2 · cP4 · Pm-3m (221)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–2373.29 K, x(Pt) 0.76992–0.79222	1
LIQUID phase:hf-pt:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 1722.83–4000 K, x(Pt) 0–1	1

BCC_A2 (Hf–Pt)

Id: phase:hf-pt: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): 1660–2517.83 K, x(Pt) 0–0.09811
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:hf-pt:bcc-a2
tdb: tdb:HfPt-18Yan.tdb:A2_BCC, tdb:HfPt-18Yan.tdb:BCC_A2

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

HfPt-18Yan.tdb: A2_BCC, type code %B, sha256 60cd809cc91cb6cb…

43: PHASE A2_BCC %B 2 1 3 !
44: CONST A2_BCC : HF% PT : VA : !

HfPt-18Yan.tdb: BCC_A2, type code %B, sha256 60cd809cc91cb6cb…

38: PHASE BCC_A2 %B 2 1 3 !
39: CONST BCC_A2 : HF% PT : VA : !

Example references (1 of 1; assessments first):

doi:10.3139/146.111676 B. Yang, C. Guo, C. Li, Z. Du, Int. J. Mater. Res., 109, 851-57(2018).
assessment that models this phase

B2_BCC (Hf–Pt)

Id: phase:hf-pt:bcc-b2; status assigned
Structure: CsCl · B2 · cP2 · Pm-3m (221); type st:b2-cscl-cp2; tier A: standard phase name; confidence high
Caveat: HfPt-18Yan.tdb: ordered phase with disordered part A2_BCC (order/disorder model)
Caveat: partitioned order/disorder model in HfPt-18Yan.tdb also describes the disordered state
Stability: stable in 1 of 1 calculated diagram(s): 1652.71–2517.98 K, x(Pt) 0–0.50186
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-pt:bcc-b2
tdb: tdb:HfPt-18Yan.tdb:B2_BCC

TDB models of B2_BCC (1): PHASE and CONSTITUENT statements as written

HfPt-18Yan.tdb: B2_BCC, type code %BO, sha256 60cd809cc91cb6cb…

48: PHASE B2_BCC %BO 3 0.5 0.5 3 !
49: CONST B2_BCC : HF% PT : HF PT% : VA : !

Example references (1 of 1; assessments first):

doi:10.3139/146.111676 B. Yang, C. Guo, C. Li, Z. Du, Int. J. Mater. Res., 109, 851-57(2018).
assessment that models this phase

FCC_A1 (Hf–Pt)

Id: phase:hf-pt: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): 300–2183.35 K, x(Pt) 0.8398–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-pt:fcc-a1
tdb: tdb:HfPt-18Yan.tdb:FCC_A1

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

HfPt-18Yan.tdb: FCC_A1, type code %A, sha256 60cd809cc91cb6cb…

33: PHASE FCC_A1 %A 2 1 1 !
34: CONST FCC_A1 : HF PT% : VA : !

Example references (1 of 1; assessments first):

doi:10.3139/146.111676 B. Yang, C. Guo, C. Li, Z. Du, Int. J. Mater. Res., 109, 851-57(2018).
assessment that models this phase

HCP_A3 (Hf–Pt)

Id: phase:hf-pt: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): 890–1900 K
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:hf-pt:hcp-a3
tdb: tdb:HfPt-18Yan.tdb:A3_HCP, tdb:HfPt-18Yan.tdb:HCP_A3

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

HfPt-18Yan.tdb: A3_HCP, type code %A, sha256 60cd809cc91cb6cb…

58: PHASE A3_HCP %A 2 1 0.5 !
59: CONST A3_HCP : HF% PT : VA : !

HfPt-18Yan.tdb: HCP_A3, type code %A, sha256 60cd809cc91cb6cb…

53: PHASE HCP_A3 %A 2 1 0.5 !
54: CONST HCP_A3 : HF% PT : VA : !

Example references (1 of 1; assessments first):

doi:10.3139/146.111676 B. Yang, C. Guo, C. Li, Z. Du, Int. J. Mater. Res., 109, 851-57(2018).
assessment that models this phase

D024_HCP (Hf–Pt)

Id: phase:hf-pt:hcp-d024; status needs_review
No structure assigned. Why: assessment_declared_blocked_by:lattice_word_HCP_contradicts_D024; lattice_word_HCP_contradicts_D024
Candidate (dft_mp): Cmcm (63) — on-hull MP HfPt at x(PT)=0.5000
Candidate (dft_mp): P6_3/mmc (194) — on-hull MP HfPt3 at x(PT)=0.7500
Candidate (dft_oqmd): Cmcm (63) — on-hull OQMD Hf1 Pt1 at x(PT)=0.5000
Candidate (dft_oqmd): P63/mmc (194) — on-hull OQMD Hf1 Pt3 at x(PT)=0.7500
Candidate (dft_oqmd): R3m (160) — on-hull OQMD Hf17 Pt7 at x(PT)=0.2917
Candidate (dft_oqmd): Fd-3m (227) — on-hull OQMD Hf2 Pt1 at x(PT)=0.3333
Candidate (dft_oqmd): Cmca (64) — on-hull OQMD Hf7 Pt10 at x(PT)=0.5882
Candidate (name_token): Ni3Ti · D0_24 · hP16 · P6_3/mmc (194) — Strukturbericht/word 'D024' in the TDB name
Stability: stable in 1 of 1 calculated diagram(s): 300–2522.04 K, x(Pt) 0–0.75
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-pt:hcp-d024
tdb: tdb:HfPt-18Yan.tdb:D024_HCP

TDB models of D024_HCP (1): PHASE and CONSTITUENT statements as written

HfPt-18Yan.tdb: D024_HCP, type code %AZ, sha256 60cd809cc91cb6cb…

63: PHASE D024_HCP %AZ 3 0.25 0.75 0.5 !
64: CONST D024_HCP : HF% PT : HF PT% : VA : !

Example references (1 of 1; assessments first):

doi:10.3139/146.111676 B. Yang, C. Guo, C. Li, Z. Du, Int. J. Mater. Res., 109, 851-57(2018).
assessment that models this phase

HF2PT (Hf–Pt)

Id: phase:hf-pt:hf2pt; status assigned
Structure: NiTi2 · cF96 · Fd-3m (227); type st:niti2-cf96; 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_structure_token, off_stoichiometric_model); structure as stated in the SGTE crystallographic table for this phase name and system
Stability: stable in 1 of 1 calculated diagram(s): 300–1933.11 K, x(Pt) 0.31463–0.33333
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-pt:hf2pt
tdb: tdb:HfPt-18Yan.tdb:HF2PT

TDB models of HF2PT (1): PHASE and CONSTITUENT statements as written

HfPt-18Yan.tdb: HF2PT, type code %, sha256 60cd809cc91cb6cb…

68: PHASE HF2PT % 2 2 1 !
69: CONST HF2PT : HF : HF PT% : !

Example references (1 of 1; assessments first):

doi:10.3139/146.111676 B. Yang, C. Guo, C. Li, Z. Du, Int. J. Mater. Res., 109, 851-57(2018).
assessment that models this phase

HF2PT3 (Hf–Pt)

Id: phase:hf-pt:hf2pt3; status assigned
Structure: Pd3Ti2 · oC20 · Cmcm (63); type st:pd3ti2-oc20; 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: Hf 0.4000, Pt 0.6000
Stability: stable in 1 of 1 calculated diagram(s): 300–1960 K, x(Pt) 0.6–0.6
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-pt:hf2pt3
tdb: tdb:HfPt-18Yan.tdb:HF2PT3

TDB models of HF2PT3 (1): PHASE and CONSTITUENT statements as written

HfPt-18Yan.tdb: HF2PT3, type code %, sha256 60cd809cc91cb6cb…

83: PHASE HF2PT3 % 2 2 3 !
84: CONST HF2PT3 : HF : PT : !

Example references (1 of 1; assessments first):

doi:10.3139/146.111676 B. Yang, C. Guo, C. Li, Z. Du, Int. J. Mater. Res., 109, 851-57(2018).
assessment that models this phase

HF3PT4 (Hf–Pt)

Id: phase:hf-pt:hf3pt4; status assigned
Structure: Pd4Pu3 · hR14 · R-3 (148); type st:pd4pu3-hr14; 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_structure_token, off_stoichiometric_model); structure as stated in the SGTE crystallographic table for this phase name and system
Stability: stable in 1 of 1 calculated diagram(s): 300–2373.26 K, x(Pt) 0.53505–0.57118
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-pt:hf3pt4
tdb: tdb:HfPt-18Yan.tdb:HF3PT4

TDB models of HF3PT4 (1): PHASE and CONSTITUENT statements as written

HfPt-18Yan.tdb: HF3PT4, type code %, sha256 60cd809cc91cb6cb…

78: PHASE HF3PT4 % 2 3 4 !
79: CONST HF3PT4 : HF% PT : HF PT% : !

Example references (1 of 1; assessments first):

doi:10.3139/146.111676 B. Yang, C. Guo, C. Li, Z. Du, Int. J. Mater. Res., 109, 851-57(2018).
assessment that models this phase

HFPT_B33 (Hf–Pt)

Id: phase:hf-pt:hfpt-b33; status assigned
Structure: CrB · B33 · oC8 · Cmcm (63); type st:b33-crb-oc8; tier A: standard phase name; confidence high
Caveat: partitioned order/disorder model in HfPt-18Yan.tdb also describes the disordered state
Stability: stable in 1 of 1 calculated diagram(s): 300–1960 K, x(Pt) 0.46335–0.5
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-pt:hfpt-b33
tdb: tdb:HfPt-18Yan.tdb:HFPT_B33

TDB models of HFPT_B33 (1): PHASE and CONSTITUENT statements as written

HfPt-18Yan.tdb: HFPT_B33, type code %, sha256 60cd809cc91cb6cb…

73: PHASE HFPT_B33 % 2 1 1 !
74: CONST HFPT_B33 : HF% PT : HF PT% : !

Example references (1 of 1; assessments first):

doi:10.3139/146.111676 B. Yang, C. Guo, C. Li, Z. Du, Int. J. Mater. Res., 109, 851-57(2018).
assessment that models this phase

HFPT4_L12 (Hf–Pt)

Id: phase:hf-pt:hfpt4-l12; status assigned
Structure: AuCu3 · L1_2 · cP4 · Pm-3m (221); type st:l1-2-aucu3-cp4; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–2373.29 K, x(Pt) 0.76992–0.79222
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-pt:hfpt4-l12
tdb: tdb:HfPt-18Yan.tdb:HFPT4_L12

TDB models of HFPT4_L12 (1): PHASE and CONSTITUENT statements as written

HfPt-18Yan.tdb: HFPT4_L12, type code %, sha256 60cd809cc91cb6cb…

88: PHASE HFPT4_L12 % 2 1 3 !
89: CONST HFPT4_L12 : HF% PT : PT : !

Example references (1 of 1; assessments first):

doi:10.3139/146.111676 B. Yang, C. Guo, C. Li, Z. Du, Int. J. Mater. Res., 109, 851-57(2018).
assessment that models this phase

LIQUID (Hf–Pt)

Id: phase:hf-pt:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1722.83–4000 K, x(Pt) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:hf-pt:liquid
tdb: tdb:HfPt-18Yan.tdb:LIQUID

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

HfPt-18Yan.tdb: LIQUID, type code %, sha256 60cd809cc91cb6cb…

28: PHASE LIQUID:L % 1 1 !
29: CONST LIQUID:L : HF PT : !

Example references (1 of 1; assessments first):

doi:10.3139/146.111676 B. Yang, C. Guo, C. Li, Z. Du, Int. J. Mater. Res., 109, 851-57(2018).
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}
}