S–Ti phases

13 phases (tier A 6, tier C 5, liquid 1, needs_review 1); 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 · Markdown · field reference

Phases of the S–Ti system (13)
Phase	Structure	Basis	Stability (calculated)	TDB models
ORTHORHOMBIC_A16 phase:s-ti:a16-orthorhombic	alpha-S · A16 · oF128 · Fddd (70)	tier A: standard phase name	not stable in 1 calculated diagram(s)	1
BCC_A2 phase:s-ti:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300.05–2499.73 K, x(S) 0–0	1
FCC_A1 phase:s-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:s-ti:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1155.05 K, x(S) 0–2e-05	1
LIQUID phase:s-ti:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 300–2500 K, x(S) 0–1	1
MONOCLINIC_S phase:s-ti:s-monoclinic		needs_review	not stable in 1 calculated diagram(s)	1
TI2S phase:s-ti:ti2s	Ta2P · oP36 · Pnnm (58)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–1690.79 K, x(S) 0.32506–0.3599	1
TI8S10 phase:s-ti:ti8s10	TiS-10H · hP20 · P6_3/mmc (194)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–2123.74 K, x(S) 0.55556–0.55556	1
TI8S3 phase:s-ti:ti8s3	Ti8S3 · mC88 · C2/m (12)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–1579.37 K, x(S) 0.27273–0.27273	1
TI8S9 phase:s-ti:ti8s9	TiS-9R · hR6 · R-3m (166)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–2253.98 K, x(S) 0.52941–0.52941	1
TIS_B81 phase:s-ti:tis-b81	NiAs · B8_1 · hP4 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–2037.16 K, x(S) 0.47981–0.5	1
TIS2_C6 phase:s-ti:tis2-c6	CdI2 · C6 · hP3 · P-3m1 (164)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–2023.18 K, x(S) 0.64481–0.66003	1
TIS3 phase:s-ti:tis3	ZrSe3 · mP8 · P2_1/m (11)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–838.84 K, x(S) 0.75–0.75	1

ORTHORHOMBIC_A16 (S–Ti)

Id: phase:s-ti:a16-orthorhombic; status assigned
Structure: alpha-S · A16 · oF128 · Fddd (70); type st:a16-alpha-s-of128; tier A: standard phase name; confidence high
Stoichiometry: S 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:s-ti:a16-orthorhombic
tdb: tdb:TiS-17Hir.tdb:ORTHORHOMBIC_A16

TDB models of ORTHORHOMBIC_A16 (1): PHASE and CONSTITUENT statements as written

TiS-17Hir.tdb: ORTHORHOMBIC_A16, type code %, sha256 f4b8b71ea4278134…

50: PHASE ORTHORHOMBIC_A16 % 1 1 !
51: CONST ORTHORHOMBIC_A16 : S : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

BCC_A2 (S–Ti)

Id: phase:s-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): 300.05–2499.73 K, x(S) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:s-ti:bcc-a2
tdb: tdb:TiS-17Hir.tdb:BCC_A2

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

TiS-17Hir.tdb: BCC_A2, type code %B, sha256 f4b8b71ea4278134…

40: PHASE BCC_A2 %B 2 1 3 !
41: CONST BCC_A2 : S TI% : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

FCC_A1 (S–Ti)

Id: phase:s-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:s-ti:fcc-a1
tdb: tdb:TiS-17Hir.tdb:FCC_A1

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

TiS-17Hir.tdb: FCC_A1, type code %A, sha256 f4b8b71ea4278134…

35: PHASE FCC_A1 %A 2 1 1 !
36: CONST FCC_A1 : S TI : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

HCP_A3 (S–Ti)

Id: phase:s-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
Stability: stable in 1 of 1 calculated diagram(s): 300–1155.05 K, x(S) 0–2e-05
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:s-ti:hcp-a3
tdb: tdb:TiS-17Hir.tdb:HCP_A3

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

TiS-17Hir.tdb: HCP_A3, type code %A, sha256 f4b8b71ea4278134…

45: PHASE HCP_A3 %A 2 1 0.5 !
46: CONST HCP_A3 : S TI% : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

LIQUID (S–Ti)

Id: phase:s-ti:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–2500 K, x(S) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:s-ti:liquid
tdb: tdb:TiS-17Hir.tdb:LIQUID

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

TiS-17Hir.tdb: LIQUID, type code %, sha256 f4b8b71ea4278134…

30: PHASE LIQUID:L % 1 1 !
31: CONST LIQUID:L : S TI : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

MONOCLINIC_S (S–Ti)

Id: phase:s-ti:s-monoclinic; status needs_review
No structure assigned. Why: name_has_descriptive_tokens:MONOCLINIC; no_structure_token
Candidate (sgte_mmc2): beta-S · mP48 · P2_1/c (14) — Hallstedt 2025 mmc2 row for MONOCLINIC_S: beta-S
Candidate (tdb_comment): beta-S · mP48 · P2_1/a — TiS-17Hir.tdb: 'Prototype beta-S (mP48, P2_1/a)'
Stoichiometry: S 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:s-ti:s-monoclinic
tdb: tdb:TiS-17Hir.tdb:MONOCLINIC_S

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

TiS-17Hir.tdb: MONOCLINIC_S, type code %, sha256 f4b8b71ea4278134…

55: PHASE MONOCLINIC_S % 1 1 !
56: CONST MONOCLINIC_S : S : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

TI2S (S–Ti)

Id: phase:s-ti:ti2s; status assigned
Structure: Ta2P · oP36 · Pnnm (58); type st:ta2p-op36; 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): 300–1690.79 K, x(S) 0.32506–0.3599
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:s-ti:ti2s
tdb: tdb:TiS-17Hir.tdb:TI2S

TDB models of TI2S (1): PHASE and CONSTITUENT statements as written

TiS-17Hir.tdb: TI2S, type code %, sha256 f4b8b71ea4278134…

65: PHASE TI2S % 2 2 1 !
66: CONST TI2S : TI% VA : S% VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

TI8S10 (S–Ti)

Id: phase:s-ti:ti8s10; status assigned
Structure: TiS-10H · hP20 · P6_3/mmc (194); type st:tis-10h-hp20; 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: S 0.5556, Ti 0.4444
Stability: stable in 1 of 1 calculated diagram(s): 300–2123.74 K, x(S) 0.55556–0.55556
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:s-ti:ti8s10
tdb: tdb:TiS-17Hir.tdb:TI8S10

TDB models of TI8S10 (1): PHASE and CONSTITUENT statements as written

TiS-17Hir.tdb: TI8S10, type code %, sha256 f4b8b71ea4278134…

80: PHASE TI8S10 % 2 8 10 !
81: CONST TI8S10 : TI : S : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

TI8S3 (S–Ti)

Id: phase:s-ti:ti8s3; status assigned
Structure: Ti8S3 · mC88 · C2/m (12); type st:ti8s3-mc88; 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: S 0.2727, Ti 0.7273
Stability: stable in 1 of 1 calculated diagram(s): 300–1579.37 K, x(S) 0.27273–0.27273
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:s-ti:ti8s3
tdb: tdb:TiS-17Hir.tdb:TI8S3

TDB models of TI8S3 (1): PHASE and CONSTITUENT statements as written

TiS-17Hir.tdb: TI8S3, type code %, sha256 f4b8b71ea4278134…

60: PHASE TI8S3 % 2 8 3 !
61: CONST TI8S3 : TI : S : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

TI8S9 (S–Ti)

Id: phase:s-ti:ti8s9; status assigned
Structure: TiS-9R · hR6 · R-3m (166); type st:tis-9r-hr6; 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: S 0.5294, Ti 0.4706
Stability: stable in 1 of 1 calculated diagram(s): 300–2253.98 K, x(S) 0.52941–0.52941
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:s-ti:ti8s9
tdb: tdb:TiS-17Hir.tdb:TI8S9

TDB models of TI8S9 (1): PHASE and CONSTITUENT statements as written

TiS-17Hir.tdb: TI8S9, type code %, sha256 f4b8b71ea4278134…

75: PHASE TI8S9 % 2 8 9 !
76: CONST TI8S9 : TI : S : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

TIS_B81 (S–Ti)

Id: phase:s-ti:tis-b81; status assigned
Structure: NiAs · B8_1 · hP4 · P6_3/mmc (194); type st:b8-1-nias-hp4; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–2037.16 K, x(S) 0.47981–0.5
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:s-ti:tis-b81
tdb: tdb:TiS-17Hir.tdb:TIS_B81

TDB models of TIS_B81 (1): PHASE and CONSTITUENT statements as written

TiS-17Hir.tdb: TIS_B81, type code %, sha256 f4b8b71ea4278134…

70: PHASE TIS_B81 % 2 1 1 !
71: CONST TIS_B81 : TI% VA : S% VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

TIS2_C6 (S–Ti)

Id: phase:s-ti:tis2-c6; status assigned
Structure: CdI2 · C6 · hP3 · P-3m1 (164); type st:c6-cdi2-hp3; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–2023.18 K, x(S) 0.64481–0.66003
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:s-ti:tis2-c6
tdb: tdb:TiS-17Hir.tdb:TIS2_C6

TDB models of TIS2_C6 (1): PHASE and CONSTITUENT statements as written

TiS-17Hir.tdb: TIS2_C6, type code %, sha256 f4b8b71ea4278134…

85: PHASE TIS2_C6 % 2 1 2 !
86: CONST TIS2_C6 : TI% VA : S% VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
assessment that models this phase

TIS3 (S–Ti)

Id: phase:s-ti:tis3; status assigned
Structure: ZrSe3 · mP8 · P2_1/m (11); type st:zrse3-mp8; 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): 300–838.84 K, x(S) 0.75–0.75
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:s-ti:tis3
tdb: tdb:TiS-17Hir.tdb:TIS3

TDB models of TIS3 (1): PHASE and CONSTITUENT statements as written

TiS-17Hir.tdb: TIS3, type code %, sha256 f4b8b71ea4278134…

90: PHASE TIS3 % 2 1 3 !
91: CONST TIS3 : TI : S% VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2017.02.006 K. Hirata, S. Iikubo, H. Fujimoto, H. Ohtani, Calphad, 57, 62-77(2017).
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}
}