Al–S phases

9 phases (tier A 5, tier C 1, liquid 1, needs_review 2); 6 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–S system page · Markdown · field reference

Phases of the Al–S system (9)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
ORTHORHOMBIC_A16 phase:al-s:a16-orthorhombic	alpha-S · A16 · oF128 · Fddd (70)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–384.34 K, x(S) 1–1	0	1
AL2S3_ALPHA phase:al-s:al2s3-alpha	Al2S3-alpha · hP30 · P6_1 (169)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–1273.69 K, x(S) 0.6–0.6	6	1
AL2S3_D51 phase:al-s:al2s3-d51	alpha-Al2O3 · D5_1 · hR10 · R-3c (167)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 1273.69–1363.53 K, x(S) 0.6–0.6	9	1
ALS phase:al-s:als		needs_review	stable in 1 of 1 calculated diagram(s): 1284.46–1332.74 K, x(S) 0.5–0.5	10	1
BCC_A2 phase:al-s:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	not stable in 1 calculated diagram(s)	4	1
FCC_A1 phase:al-s:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–933.47 K, x(S) 0–0	2	1
HCP_A3 phase:al-s:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 1 calculated diagram(s)	0	1
LIQUID phase:al-s:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 384.34–2500 K, x(S) 0–1	16	1
MONOCLINIC_S phase:al-s:s-monoclinic		needs_review	not stable in 1 calculated diagram(s)	0	1

ORTHORHOMBIC_A16 (Al–S)

Id: phase:al-s: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: stable in 1 of 1 calculated diagram(s): 300–384.34 K, x(S) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:al-s:a16-orthorhombic
tdb: tdb:AlS-19Shi.tdb:ORTHORHOMBIC_A16

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

AlS-19Shi.tdb: ORTHORHOMBIC_A16, type code %, sha256 4298f9d489e1f952…

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

Example references (1 of 1; assessments first):

doi:10.1007/s11669-019-00733-z Chenying Shi, Biaobiao Yang, Biao Hu, Yong Du, Sheng Yao, Thermodynamic Description of the Al–X (X = S, Se, Te) Systems, J. Phase Equilib. Diffus. 40, 392-402 (2019).
assessment that models this phase

AL2S3_ALPHA (Al–S)

Id: phase:al-s:al2s3-alpha; status assigned
Structure: Al2S3-alpha · hP30 · P6_1 (169); type st:al2s3-alpha-hp30; 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, polymorph_family:other phases of this system have the same composition); structure as stated in the SGTE crystallographic table for this phase name and system
Stoichiometry: Al 0.4000, S 0.6000
Stability: stable in 1 of 1 calculated diagram(s): 300–1273.69 K, x(S) 0.6–0.6
Literature: 6 values (6 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-s:al2s3-alpha
paper: paper:10.1007/s11669-019-00733-z:αAl2S3
tdb: tdb:AlS-19Shi.tdb:AL2S3_ALPHA

TDB models of AL2S3_ALPHA (1): PHASE and CONSTITUENT statements as written

AlS-19Shi.tdb: AL2S3_ALPHA, type code %, sha256 4298f9d489e1f952…

66: PHASE AL2S3_ALPHA % 2 2 3 !
67: CONST AL2S3_ALPHA : AL : S : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-019-00733-z Chenying Shi, Biaobiao Yang, Biao Hu, Yong Du, Sheng Yao, Thermodynamic Description of the Al–X (X = S, Se, Te) Systems, J. Phase Equilib. Diffus. 40, 392-402 (2019).
assessment that models this phase; reports values for this phase
doi:10.1007/bf02873197 R. C. Sharma, Y. A. Chang, The Al−S (Aluminum-Sulfur) system, JPE 8 (1987).
cited as the source of values for this phase

AL2S3_D51 (Al–S)

Id: phase:al-s:al2s3-d51; status assigned
Structure: alpha-Al2O3 · D5_1 · hR10 · R-3c (167); type st:d5-1-alpha-al2o3-hr10; tier A: standard phase name; confidence high
Stoichiometry: Al 0.4000, S 0.6000
Stability: stable in 1 of 1 calculated diagram(s): 1273.69–1363.53 K, x(S) 0.6–0.6
Literature: 9 values (9 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-s:al2s3-d51
paper: paper:10.1007/s11669-019-00733-z:γAl2S3
tdb: tdb:AlS-19Shi.tdb:AL2S3_D51

TDB models of AL2S3_D51 (1): PHASE and CONSTITUENT statements as written

AlS-19Shi.tdb: AL2S3_D51, type code %, sha256 4298f9d489e1f952…

71: PHASE AL2S3_D51 % 2 2 3 !
72: CONST AL2S3_D51 : AL : S : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-019-00733-z Chenying Shi, Biaobiao Yang, Biao Hu, Yong Du, Sheng Yao, Thermodynamic Description of the Al–X (X = S, Se, Te) Systems, J. Phase Equilib. Diffus. 40, 392-402 (2019).
assessment that models this phase; reports values for this phase
doi:10.1007/bf02873197 R. C. Sharma, Y. A. Chang, The Al−S (Aluminum-Sulfur) system, JPE 8 (1987).
cited as the source of values for this phase

ALS (Al–S)

Id: phase:al-s:als; status needs_review
No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
Candidate (literature_printed): (AlS) · ? — printed with a label mapped to this phase
Candidate (sgte_mmc2): (AlS) — Hallstedt 2025 mmc2 row for ALS: AlS
Stoichiometry: Al 0.5000, S 0.5000
Stability: stable in 1 of 1 calculated diagram(s): 1284.46–1332.74 K, x(S) 0.5–0.5
Literature: 10 values (10 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-s:als
paper: paper:10.1007/s11669-019-00733-z:AlS
tdb: tdb:AlS-19Shi.tdb:ALS

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

AlS-19Shi.tdb: ALS, type code %, sha256 4298f9d489e1f952…

61: PHASE ALS % 2 1 1 !
62: CONST ALS : AL : S : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-019-00733-z Chenying Shi, Biaobiao Yang, Biao Hu, Yong Du, Sheng Yao, Thermodynamic Description of the Al–X (X = S, Se, Te) Systems, J. Phase Equilib. Diffus. 40, 392-402 (2019).
assessment that models this phase; reports values for this phase
doi:10.1007/bf02873197 R. C. Sharma, Y. A. Chang, The Al−S (Aluminum-Sulfur) system, JPE 8 (1987).
cited as the source of values for this phase

BCC_A2 (Al–S)

Id: phase:al-s: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 1 calculated diagram(s)
Literature: 4 values (4 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-s:bcc-a2
paper: paper:10.1007/s11669-019-00733-z:(βS)
tdb: tdb:AlS-19Shi.tdb:BCC_A2

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

AlS-19Shi.tdb: BCC_A2, type code %B, sha256 4298f9d489e1f952…

41: PHASE BCC_A2 %B 2 1 3 !
42: CONST BCC_A2 : AL S : VA : !

Example references (1 of 1; assessments first):

doi:10.1007/s11669-019-00733-z Chenying Shi, Biaobiao Yang, Biao Hu, Yong Du, Sheng Yao, Thermodynamic Description of the Al–X (X = S, Se, Te) Systems, J. Phase Equilib. Diffus. 40, 392-402 (2019).
assessment that models this phase; reports values for this phase

FCC_A1 (Al–S)

Id: phase:al-s: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): 300–933.47 K, x(S) 0–0
Literature: 2 values (2 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:al-s:fcc-a1
paper: paper:10.1007/s11669-019-00733-z:(Al)
tdb: tdb:AlS-19Shi.tdb:FCC_A1

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

AlS-19Shi.tdb: FCC_A1, type code %A, sha256 4298f9d489e1f952…

36: PHASE FCC_A1 %A 2 1 1 !
37: CONST FCC_A1 : AL% S : VA : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-019-00733-z Chenying Shi, Biaobiao Yang, Biao Hu, Yong Du, Sheng Yao, Thermodynamic Description of the Al–X (X = S, Se, Te) Systems, J. Phase Equilib. Diffus. 40, 392-402 (2019).
assessment that models this phase; reports values for this phase
doi:10.1007/bf02873197 R. C. Sharma, Y. A. Chang, The Al−S (Aluminum-Sulfur) system, JPE 8 (1987).
cited as the source of values for this phase

HCP_A3 (Al–S)

Id: phase:al-s: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: Al 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:al-s:hcp-a3
tdb: tdb:AlS-19Shi.tdb:HCP_A3

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

AlS-19Shi.tdb: HCP_A3, type code %A, sha256 4298f9d489e1f952…

46: PHASE HCP_A3 %A 2 1 0.5 !
47: CONST HCP_A3 : AL : VA: !

Example references (1 of 1; assessments first):

doi:10.1007/s11669-019-00733-z Chenying Shi, Biaobiao Yang, Biao Hu, Yong Du, Sheng Yao, Thermodynamic Description of the Al–X (X = S, Se, Te) Systems, J. Phase Equilib. Diffus. 40, 392-402 (2019).
assessment that models this phase

LIQUID (Al–S)

Id: phase:al-s:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 384.34–2500 K, x(S) 0–1
Literature: 16 values (16 accepted) from 1 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:al-s:liquid
paper: paper:10.1007/s11669-019-00733-z:L1, paper:10.1007/s11669-019-00733-z:L2, paper:10.1007/s11669-019-00733-z:L3
tdb: tdb:AlS-19Shi.tdb:LIQUID

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

AlS-19Shi.tdb: LIQUID, type code %, sha256 4298f9d489e1f952…

31: PHASE LIQUID % 1 1 !
32: CONST LIQUID : AL AL2S3 S : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-019-00733-z Chenying Shi, Biaobiao Yang, Biao Hu, Yong Du, Sheng Yao, Thermodynamic Description of the Al–X (X = S, Se, Te) Systems, J. Phase Equilib. Diffus. 40, 392-402 (2019).
assessment that models this phase; reports values for this phase
doi:10.1007/bf02873197 R. C. Sharma, Y. A. Chang, The Al−S (Aluminum-Sulfur) system, JPE 8 (1987).
cited as the source of values for this phase

MONOCLINIC_S (Al–S)

Id: phase:al-s: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 — AlS-19Shi.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 (3): corpus: corpus:phase:al-s:s-monoclinic, corpus:phase:al-s:monoclinic-s
tdb: tdb:AlS-19Shi.tdb:MONOCLINIC_S

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

AlS-19Shi.tdb: MONOCLINIC_S, type code %, sha256 4298f9d489e1f952…

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

Example references (1 of 1; assessments first):

doi:10.1007/s11669-019-00733-z Chenying Shi, Biaobiao Yang, Biao Hu, Yong Du, Sheng Yao, Thermodynamic Description of the Al–X (X = S, Se, Te) Systems, J. Phase Equilib. Diffus. 40, 392-402 (2019).
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}
}