Gd–Si phases

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

Phases of the Gd–Si system (10)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
DIAMOND_A4 phase:gd-si:a4-diamond	C (diamond) · A4 · cF8 · Fd-3m (227)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–2499.54 K, x(Si) 1–1	0	1
BCC_A2 phase:gd-si:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 1508.16–1593.16 K, x(Si) 0–0	0	1
FCC_A1 phase:gd-si:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	not stable in 1 calculated diagram(s)	0	1
GD3SI5_C32 phase:gd-si:gd3si5-c32		needs_review	stable in 1 of 1 calculated diagram(s): 300–1936.19 K, x(Si) 0.625–0.625	0	1
GD5SI3_D88 phase:gd-si:gd5si3-d88	Mn5Si3 · D8_8 · hP16 · P6_3/mcm (193)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–2019.97 K, x(Si) 0.375–0.375	0	1
GD5SI4 phase:gd-si:gd5si4	Ge4Sm5 · oP36 · Pnma (62)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 300–2045.62 K, x(Si) 0.44444–0.44444	6	1
GDSI_B27 phase:gd-si:gdsi-b27	FeB · B27 · oP8 · Pnma (62)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–2107.12 K, x(Si) 0.5–0.5	0	1
GDSI2 phase:gd-si:gdsi2		needs_review	stable in 1 of 1 calculated diagram(s): 300–1874.01 K, x(Si) 0.66667–0.66667	0	1
HCP_A3 phase:gd-si:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1508.16 K, x(Si) 0–0	3	1
LIQUID phase:gd-si:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 1352.27–2500 K, x(Si) 0–1	21	1

DIAMOND_A4 (Gd–Si)

Id: phase:gd-si:a4-diamond; status assigned
Structure: C (diamond) · A4 · cF8 · Fd-3m (227); type st:a4-c-diamond-cf8; tier A: standard phase name; confidence high
Stoichiometry: Si 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–2499.54 K, x(Si) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:gd-si:a4-diamond
tdb: tdb:GdSi-07Hua.tdb:DIAMOND_A4

TDB models of DIAMOND_A4 (1): PHASE and CONSTITUENT statements as written

GdSi-07Hua.tdb: DIAMOND_A4, type code %, sha256 e9d1c9c91a440a0c…

46: PHASE DIAMOND_A4 % 1 1 !
47: CONST DIAMOND_A4 : SI : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2006.09.068 Mianliang Huang, Deborah L. Schlagel, Frederick A. Schmidt, Thomas A. Lograsso, Experimental investigation and thermodynamic modeling of the Gd–Si system, Journal of Alloys and Compounds 441, 94-100 (2007).
assessment that models this phase

BCC_A2 (Gd–Si)

Id: phase:gd-si: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): 1508.16–1593.16 K, x(Si) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:gd-si:bcc-a2
tdb: tdb:GdSi-07Hua.tdb:BCC_A2

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

GdSi-07Hua.tdb: BCC_A2, type code %B, sha256 e9d1c9c91a440a0c…

36: PHASE BCC_A2 %B 2 1 3 !
37: CONST BCC_A2 : GD% SI : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2006.09.068 Mianliang Huang, Deborah L. Schlagel, Frederick A. Schmidt, Thomas A. Lograsso, Experimental investigation and thermodynamic modeling of the Gd–Si system, Journal of Alloys and Compounds 441, 94-100 (2007).
assessment that models this phase

FCC_A1 (Gd–Si)

Id: phase:gd-si: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:gd-si:fcc-a1
tdb: tdb:GdSi-07Hua.tdb:FCC_A1

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

GdSi-07Hua.tdb: FCC_A1, type code %A, sha256 e9d1c9c91a440a0c…

31: PHASE FCC_A1 %A 2 1 1 !
32: CONST FCC_A1 : GD SI : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2006.09.068 Mianliang Huang, Deborah L. Schlagel, Frederick A. Schmidt, Thomas A. Lograsso, Experimental investigation and thermodynamic modeling of the Gd–Si system, Journal of Alloys and Compounds 441, 94-100 (2007).
assessment that models this phase

GD3SI5_C32 (Gd–Si)

Id: phase:gd-si:gd3si5-c32; status needs_review
No structure assigned. Why: assessment_declared_blocked_by:stoichiometry_contradicts_C32; stoichiometry_contradicts_C32:GdSi-07Hua.tdb
Candidate (dft_oqmd): Cc (9) — on-hull OQMD Gd3 Si5 at x(SI)=0.6250
Candidate (name_token): AlB2 · C32 · hP3 · P6/mmm (191) — Strukturbericht/word 'C32' in the TDB name
Candidate (sgte_mmc2): AlB2 · C32 · hP3 · P6/mmm (191) — Hallstedt 2025 mmc2 row for GD3SI5_C32: Gd3Si5
Candidate (tdb_comment): AlB2 · hP3 · P6/mmm — GdSi-07Hua.tdb: 'Prototype AlB2 (hP3, P6/mmm)'
Stoichiometry: Gd 0.3750, Si 0.6250
Stability: stable in 1 of 1 calculated diagram(s): 300–1936.19 K, x(Si) 0.625–0.625
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:gd-si:gd3si5-c32
tdb: tdb:GdSi-07Hua.tdb:GD3SI5_C32

TDB models of GD3SI5_C32 (1): PHASE and CONSTITUENT statements as written

GdSi-07Hua.tdb: GD3SI5_C32, type code %, sha256 e9d1c9c91a440a0c…

66: PHASE GD3SI5_C32 % 2 3 5 !
67: CONST GD3SI5_C32 : GD : SI : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2006.09.068 Mianliang Huang, Deborah L. Schlagel, Frederick A. Schmidt, Thomas A. Lograsso, Experimental investigation and thermodynamic modeling of the Gd–Si system, Journal of Alloys and Compounds 441, 94-100 (2007).
assessment that models this phase

GD5SI3_D88 (Gd–Si)

Id: phase:gd-si:gd5si3-d88; status assigned
Structure: Mn5Si3 · D8_8 · hP16 · P6_3/mcm (193); type st:d8-8-mn5si3-hp16; tier A: standard phase name; confidence high
Stoichiometry: Gd 0.6250, Si 0.3750
Stability: stable in 1 of 1 calculated diagram(s): 300–2019.97 K, x(Si) 0.375–0.375
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:gd-si:gd5si3-d88
tdb: tdb:GdSi-07Hua.tdb:GD5SI3_D88

TDB models of GD5SI3_D88 (1): PHASE and CONSTITUENT statements as written

GdSi-07Hua.tdb: GD5SI3_D88, type code %, sha256 e9d1c9c91a440a0c…

51: PHASE GD5SI3_D88 % 2 5 3 !
52: CONST GD5SI3_D88 : GD : SI : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2006.09.068 Mianliang Huang, Deborah L. Schlagel, Frederick A. Schmidt, Thomas A. Lograsso, Experimental investigation and thermodynamic modeling of the Gd–Si system, Journal of Alloys and Compounds 441, 94-100 (2007).
assessment that models this phase

GD5SI4 (Gd–Si)

Id: phase:gd-si:gd5si4; status assigned
Structure: Ge4Sm5 · oP36 · Pnma (62); type st:ge4sm5-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_on_hull_entry_in_oqmd, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
Stoichiometry: Gd 0.5556, Si 0.4444
Stability: stable in 1 of 1 calculated diagram(s): 300–2045.62 K, x(Si) 0.44444–0.44444
Literature: 6 values (6 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:gd-si:gd5si4
paper: paper:10.1016/j.jallcom.2006.09.068:Gd5Si4
tdb: tdb:GdSi-07Hua.tdb:GD5SI4

TDB models of GD5SI4 (1): PHASE and CONSTITUENT statements as written

GdSi-07Hua.tdb: GD5SI4, type code %, sha256 e9d1c9c91a440a0c…

56: PHASE GD5SI4 % 2 5 4 !
57: CONST GD5SI4 : GD : SI : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2006.09.068 Mianliang Huang, Deborah L. Schlagel, Frederick A. Schmidt, Thomas A. Lograsso, Experimental investigation and thermodynamic modeling of the Gd–Si system, Journal of Alloys and Compounds 441, 94-100 (2007).
assessment that models this phase; reports values for this phase

GDSI_B27 (Gd–Si)

Id: phase:gd-si:gdsi-b27; status assigned
Structure: FeB · B27 · oP8 · Pnma (62); type st:b27-feb-op8; tier A: standard phase name; confidence high
Caveat: DFT agrees: on-hull mp-aaabifpr and oqmd-12494, space group 62
Stoichiometry: Gd 0.5000, Si 0.5000
Stability: stable in 1 of 1 calculated diagram(s): 300–2107.12 K, x(Si) 0.5–0.5
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:gd-si:gdsi-b27
mp: mp:mp-aaabifpr
oqmd: oqmd:oqmd-12494
tdb: tdb:GdSi-07Hua.tdb:GDSI_B27

TDB models of GDSI_B27 (1): PHASE and CONSTITUENT statements as written

GdSi-07Hua.tdb: GDSI_B27, type code %, sha256 e9d1c9c91a440a0c…

61: PHASE GDSI_B27 % 2 1 1 !
62: CONST GDSI_B27 : GD : SI : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2006.09.068 Mianliang Huang, Deborah L. Schlagel, Frederick A. Schmidt, Thomas A. Lograsso, Experimental investigation and thermodynamic modeling of the Gd–Si system, Journal of Alloys and Compounds 441, 94-100 (2007).
assessment that models this phase

GDSI2 (Gd–Si)

Id: phase:gd-si:gdsi2; status needs_review
No structure assigned. Why: no_on_hull_entry_in_oqmd; no_structure_token
Candidate (dft_mp): I4_1/amd (141) — on-hull MP GdSi2 at x(SI)=0.6667
Candidate (tdb_comment): Si2Th · tI12 · I4_1/amd — GdSi-07Hua.tdb: 'Prototype Si2Th (tI12, I4_1/amd) and GdSi1.4 ? (oI12, Imma)'
Stoichiometry: Gd 0.3333, Si 0.6667
Stability: stable in 1 of 1 calculated diagram(s): 300–1874.01 K, x(Si) 0.66667–0.66667
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:gd-si:gdsi2
tdb: tdb:GdSi-07Hua.tdb:GDSI2

TDB models of GDSI2 (1): PHASE and CONSTITUENT statements as written

GdSi-07Hua.tdb: GDSI2, type code %, sha256 e9d1c9c91a440a0c…

71: PHASE GDSI2 % 2 1 2 !
72: CONST GDSI2 : GD : SI : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2006.09.068 Mianliang Huang, Deborah L. Schlagel, Frederick A. Schmidt, Thomas A. Lograsso, Experimental investigation and thermodynamic modeling of the Gd–Si system, Journal of Alloys and Compounds 441, 94-100 (2007).
assessment that models this phase

HCP_A3 (Gd–Si)

Id: phase:gd-si: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): 300–1508.16 K, x(Si) 0–0
Literature: 3 values (3 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:gd-si:hcp-a3
paper: paper:10.1016/j.jallcom.2006.09.068:hcp (Gd)
tdb: tdb:GdSi-07Hua.tdb:HCP_A3

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

GdSi-07Hua.tdb: HCP_A3, type code %A, sha256 e9d1c9c91a440a0c…

41: PHASE HCP_A3 %A 2 1 0.5 !
42: CONST HCP_A3 : GD% SI : VA: !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2006.09.068 Mianliang Huang, Deborah L. Schlagel, Frederick A. Schmidt, Thomas A. Lograsso, Experimental investigation and thermodynamic modeling of the Gd–Si system, Journal of Alloys and Compounds 441, 94-100 (2007).
assessment that models this phase; reports values for this phase

LIQUID (Gd–Si)

Id: phase:gd-si:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1352.27–2500 K, x(Si) 0–1
Literature: 21 values (21 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:gd-si:liquid
paper: paper:10.1016/j.jallcom.2006.09.068:Liquid
tdb: tdb:GdSi-07Hua.tdb:LIQUID

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

GdSi-07Hua.tdb: LIQUID, type code %, sha256 e9d1c9c91a440a0c…

26: PHASE LIQUID:L % 1 1 !
27: CONST LIQUID:L : GD SI : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jallcom.2006.09.068 Mianliang Huang, Deborah L. Schlagel, Frederick A. Schmidt, Thomas A. Lograsso, Experimental investigation and thermodynamic modeling of the Gd–Si system, Journal of Alloys and Compounds 441, 94-100 (2007).
assessment that models this phase; reports values for 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}
}