P–Ti phases

13 phases (tier A 6, tier B 1, tier C 1, liquid 1, needs_review 4); 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 · Markdown · field reference

Phases of the P–Ti system (13)
Phase	Structure	Basis	Stability (calculated)	TDB models
BCC_A2 phase:p-ti:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 1154.99–2499.94 K, x(P) 0–0.00321	1
M2P_C22 phase:p-ti:c22-m2p	Fe2P · C22 · hP9 · P-62m (189)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–2192.61 K, x(P) 0.33333–0.33333	1
FCC_A1 phase:p-ti:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	not stable in 1 calculated diagram(s)	1
HCP_A3 phase:p-ti:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1939.99 K, x(P) 0–0	1
LIQUID phase:p-ti:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 852.3–2500 K, x(P) 0–1	1
RED_P phase:p-ti:p-red		needs_review	stable in 1 of 1 calculated diagram(s): 300–852.3 K, x(P) 1–1	1
WHITE_P phase:p-ti:p-white		needs_review	not stable in 1 calculated diagram(s)	1
TI3P phase:p-ti:ti3p	Ti3P · tP32 · P4_2/n (86)	tier B: DFT-supported (unique MP + OQMD match)	stable in 1 of 1 calculated diagram(s): 300–2036.93 K, x(P) 0.25–0.25	1
TI4P3_D73 phase:p-ti:ti4p3-d73	Th3P4 · D7_3 · cI28 · I-43d (220)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 600.91–2333.53 K, x(P) 0.42857–0.42857	1
TI5P3_ALPHA phase:p-ti:ti5p3-alpha		needs_review	stable in 1 of 1 calculated diagram(s): 300–2105.93 K, x(P) 0.37–0.37	1
TI5P3_D88 phase:p-ti:ti5p3-d88		needs_review	stable in 1 of 1 calculated diagram(s): 300–2360.75 K, x(P) 0.36129–0.39	1
TIP_BI phase:p-ti:tip-bi	TiAs · B_i · hP8 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–2268.81 K, x(P) 0.48437–0.5	1
TIP2_C37 phase:p-ti:tip2-c37	Co2Si · C37 · oP12 · Pnma (62)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1856.49 K, x(P) 0.66667–0.66667	1

BCC_A2 (P–Ti)

Id: phase:p-ti: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): 1154.99–2499.94 K, x(P) 0–0.00321
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:p-ti:bcc-a2
tdb: tdb:TiP-06Oht.tdb:BCC_A2

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

TiP-06Oht.tdb: BCC_A2, type code %B, sha256 e79ac2694bb46a76…

35: PHASE BCC_A2 %B 2 1 3 !
36: CONST BCC_A2 : P TI% : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

M2P_C22 (P–Ti)

Id: phase:p-ti:c22-m2p; status assigned
Structure: Fe2P · C22 · hP9 · P-62m (189); type st:c22-fe2p-hp9; 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 (unrecognised_name_tokens:M2P); structure as stated in the SGTE crystallographic table for this phase name and system
Stoichiometry: P 0.3333, Ti 0.6667
Stability: stable in 1 of 1 calculated diagram(s): 300–2192.61 K, x(P) 0.33333–0.33333
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:p-ti:c22-m2p
tdb: tdb:TiP-06Oht.tdb:M2P_C22

TDB models of M2P_C22 (1): PHASE and CONSTITUENT statements as written

TiP-06Oht.tdb: M2P_C22, type code %, sha256 e79ac2694bb46a76…

60: PHASE M2P_C22 % 2 2 1 !
61: CONST M2P_C22 : TI : P : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

FCC_A1 (P–Ti)

Id: phase:p-ti:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
Stability: not stable in 1 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:p-ti:fcc-a1
tdb: tdb:TiP-06Oht.tdb:FCC_A1

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

TiP-06Oht.tdb: FCC_A1, type code %A, sha256 e79ac2694bb46a76…

30: PHASE FCC_A1 %A 2 1 1 !
31: CONST FCC_A1 : P TI : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

HCP_A3 (P–Ti)

Id: phase:p-ti:hcp-a3; status assigned
Structure: Mg · A3 · hP2 · P6_3/mmc (194); type st:a3-mg-hp2; tier A: standard phase name; confidence high
Stoichiometry: Ti 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–1939.99 K, x(P) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:p-ti:hcp-a3
tdb: tdb:TiP-06Oht.tdb:HCP_A3

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

TiP-06Oht.tdb: HCP_A3, type code %A, sha256 e79ac2694bb46a76…

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

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

LIQUID (P–Ti)

Id: phase:p-ti:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 852.3–2500 K, x(P) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:p-ti:liquid
tdb: tdb:TiP-06Oht.tdb:LIQUID

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

TiP-06Oht.tdb: LIQUID, type code %, sha256 e79ac2694bb46a76…

25: PHASE LIQUID:L % 1 1 !
26: CONST LIQUID:L : P TI : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

RED_P (P–Ti)

Id: phase:p-ti:p-red; status needs_review
No structure assigned. Why: name_has_descriptive_tokens:RED; no_structure_token
Candidate (sgte_mmc2): (Red P) — Hallstedt 2025 mmc2 row for RED_P: Red P
Stoichiometry: P 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–852.3 K, x(P) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:p-ti:p-red
tdb: tdb:TiP-06Oht.tdb:RED_P

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

TiP-06Oht.tdb: RED_P, type code %, sha256 e79ac2694bb46a76…

50: PHASE RED_P % 1 1 !
51: CONST RED_P : P : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

WHITE_P (P–Ti)

Id: phase:p-ti:p-white; status needs_review
No structure assigned. Why: name_has_descriptive_tokens:WHITE; no_structure_token
Candidate (sgte_mmc2): (White P) — Hallstedt 2025 mmc2 row for WHITE_P: White P
Stoichiometry: P 1.0000
Stability: not stable in 1 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:p-ti:p-white
tdb: tdb:TiP-06Oht.tdb:WHITE_P

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

TiP-06Oht.tdb: WHITE_P, type code %, sha256 e79ac2694bb46a76…

45: PHASE WHITE_P % 1 1 !
46: CONST WHITE_P : P : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

TI3P (P–Ti)

Id: phase:p-ti:ti3p; status assigned
Structure: Ti3P · tP32 · P4_2/n (86); type st:ti3p-tp32; tier B: DFT-supported (unique MP + OQMD match); confidence high
Stoichiometry: P 0.2500, Ti 0.7500
Stability: stable in 1 of 1 calculated diagram(s): 300–2036.93 K, x(P) 0.25–0.25
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:p-ti:ti3p
mp: mp:mp-aaaabueo
oqmd: oqmd:oqmd-7984
tdb: tdb:TiP-06Oht.tdb:TI3P

TDB models of TI3P (1): PHASE and CONSTITUENT statements as written

TiP-06Oht.tdb: TI3P, type code %, sha256 e79ac2694bb46a76…

55: PHASE TI3P % 2 3 1 !
56: CONST TI3P : TI : P : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

TI4P3_D73 (P–Ti)

Id: phase:p-ti:ti4p3-d73; status assigned
Structure: Th3P4 · D7_3 · cI28 · I-43d (220); type st:d7-3-th3p4-ci28; tier A: standard phase name; confidence high
Stoichiometry: P 0.4286, Ti 0.5714
Stability: stable in 1 of 1 calculated diagram(s): 600.91–2333.53 K, x(P) 0.42857–0.42857
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:p-ti:ti4p3-d73
tdb: tdb:TiP-06Oht.tdb:TI4P3_D73

TDB models of TI4P3_D73 (1): PHASE and CONSTITUENT statements as written

TiP-06Oht.tdb: TI4P3_D73, type code %, sha256 e79ac2694bb46a76…

75: PHASE TI4P3_D73 % 2 4 3 !
76: CONST TI4P3_D73 : TI : P : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

TI5P3_ALPHA (P–Ti)

Id: phase:p-ti:ti5p3-alpha; status needs_review
No structure assigned. Why: assessment_declared_compound_differs_from_model_composition; no_on_hull_entry_in_both; no_structure_token
Candidate (sgte_mmc2): Sb3Yb5 · oP32 · Pnma (62) — Hallstedt 2025 mmc2 row for TI5P3_ALPHA: Ti5P3 (Ti1.7P)
Candidate (tdb_comment): Sb3Yb5 · oP32 · Pnma — TiP-06Oht.tdb: 'Prototype Sb3Yb5 (oP32, Pnma), Ti1.7P'
Stoichiometry: P 0.3700, Ti 0.6300
Stability: stable in 1 of 1 calculated diagram(s): 300–2105.93 K, x(P) 0.37–0.37
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:p-ti:ti5p3-alpha
tdb: tdb:TiP-06Oht.tdb:TI5P3_ALPHA

TDB models of TI5P3_ALPHA (1): PHASE and CONSTITUENT statements as written

TiP-06Oht.tdb: TI5P3_ALPHA, type code %, sha256 e79ac2694bb46a76…

65: PHASE TI5P3_ALPHA % 2 0.63 0.37 !
66: CONST TI5P3_ALPHA : TI : P : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

TI5P3_D88 (P–Ti)

Id: phase:p-ti:ti5p3-d88; status needs_review
No structure assigned. Why: assessment_declared_blocked_by:site_ratios_contradict_D8_8; site_ratios_contradict_D8_8:TiP-06Oht.tdb
Candidate (name_token): Mn5Si3 · D8_8 · hP16 · P6_3/mcm (193) — Strukturbericht/word 'D88' in the TDB name
Candidate (sgte_mmc2): Mn5Si3 · D8_8 · hP16 · P6_3/mcm (193) — Hallstedt 2025 mmc2 row for TI5P3_D88: Ti5P3
Candidate (tdb_comment): Mn5Si3 · hP16 · P6_3/mcm — TiP-06Oht.tdb: 'Prototype Mn5Si3 (hP16, P6_3/mcm)'
Stability: stable in 1 of 1 calculated diagram(s): 300–2360.75 K, x(P) 0.36129–0.39
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:p-ti:ti5p3-d88
tdb: tdb:TiP-06Oht.tdb:TI5P3_D88

TDB models of TI5P3_D88 (1): PHASE and CONSTITUENT statements as written

TiP-06Oht.tdb: TI5P3_D88, type code %, sha256 e79ac2694bb46a76…

70: PHASE TI5P3_D88 % 2 0.61 0.39 !
71: CONST TI5P3_D88 : TI : P% TI : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

TIP_BI (P–Ti)

Id: phase:p-ti:tip-bi; status assigned
Structure: TiAs · B_i · hP8 · P6_3/mmc (194); type st:b-i-tias-hp8; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–2268.81 K, x(P) 0.48437–0.5
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:p-ti:tip-bi
tdb: tdb:TiP-06Oht.tdb:TIP_BI

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

TiP-06Oht.tdb: TIP_BI, type code %, sha256 e79ac2694bb46a76…

80: PHASE TIP_BI % 2 1 1 !
81: CONST TIP_BI : TI : P% TI : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
assessment that models this phase

TIP2_C37 (P–Ti)

Id: phase:p-ti:tip2-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-aaaabebv and oqmd-4606, space group 62
Stoichiometry: P 0.6667, Ti 0.3333
Stability: stable in 1 of 1 calculated diagram(s): 300–1856.49 K, x(P) 0.66667–0.66667
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:p-ti:tip2-c37
mp: mp:mp-aaaabebv
oqmd: oqmd:oqmd-4606
tdb: tdb:TiP-06Oht.tdb:TIP2_C37

TDB models of TIP2_C37 (1): PHASE and CONSTITUENT statements as written

TiP-06Oht.tdb: TIP2_C37, type code %, sha256 e79ac2694bb46a76…

85: PHASE TIP2_C37 % 2 1 2 !
86: CONST TIP2_C37 : TI : P : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2005.09.006 H. Ohtani, N. Hanaya, M. Hasebe, S. Teraoka, M. Abe, Calphad, 30, 147-58(2006).
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}
}