# Pt–Si phases

> Pt–Si system: 15 phases (tier A 7, tier B 1, tier C 4, liquid 1, needs_review 2); 13 stable in a calculated diagram in the ORCHID phase registry, with names, structure type when the stored evidence supports an assignment under the stated tier rules, calculated stability, verbatim TDB PHASE/CONSTITUENT statements and example references.

HTML: https://data.orchid-project.org/phases/pages/PT-SI.html · Markdown: https://data.orchid-project.org/phases/pages/PT-SI.md

15 phases (tier A 7, tier B 1, tier C 4, liquid 1, needs_review 2); 13 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](https://orchid-project.org/phases/?q=PT-SI) · [full JSON](https://data.orchid-project.org/phases/systems/PT-SI.json) · [Pt–Si system page](https://data.orchid-project.org/systems/PT-SI.html) · [Markdown](https://data.orchid-project.org/phases/pages/PT-SI.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md)

Table: Phases of the Pt–Si system (15)

| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---:|---:|
| [DIAMOND_A4](#phase-pt-si-a4-diamond); _phase:pt-si:a4-diamond_ | C (diamond) · A4 · cF8 · Fd-3m (227) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–2499.68 K, x(Si) 1–1 | 3 | 1 |
| [BCC_A2](#phase-pt-si-bcc-a2); _phase:pt-si:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | not stable in 1 calculated diagram(s) | 0 | 1 |
| [FCC_A1](#phase-pt-si-fcc-a1); _phase:pt-si:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–2063.01 K, x(Si) 0–0.01071 | 5 | 1 |
| [HCP_A3](#phase-pt-si-hcp-a3); _phase:pt-si: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-pt-si-liquid); _phase:pt-si:liquid_ | liquid | liquid | stable in 1 of 1 calculated diagram(s): 1124.26–2500 K, x(Si) 0–1 | 20 | 1 |
| [PT17SI8_ALPHA](#phase-pt-si-pt17si8-alpha); _phase:pt-si:pt17si8-alpha_ | Pt12Si5 · tP68 · P4/n (85) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 1042.99–1280 K, x(Si) 0.32–0.32 | 2 | 1 |
| [PT17SI8_BETA](#phase-pt-si-pt17si8-beta); _phase:pt-si:pt17si8-beta_ | Ni12P5 · tI34 · I4/m (87) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1042.99 K, x(Si) 0.32–0.32 | 8 | 1 |
| [PT25SI7](#phase-pt-si-pt25si7); _phase:pt-si:pt25si7_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300–1115.4 K, x(Si) 0.218–0.218 | 2 | 1 |
| [PT2SI_C22](#phase-pt-si-pt2si-c22); _phase:pt-si:pt2si-c22_ | Fe2P · C22 · hP9 · P-62m (189) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 1017.54–1378.31 K, x(Si) 0.33333–0.33333 | 3 | 1 |
| [PT2SI_L2B](#phase-pt-si-pt2si-l2b); _phase:pt-si:pt2si-l2b_ | ThH2 · L'2_b · tI6 · I4/mmm (139) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 323.56–1017.54 K, x(Si) 0.33333–0.33333 | 10 | 1 |
| [PT3SI_ALPHA](#phase-pt-si-pt3si-alpha); _phase:pt-si:pt3si-alpha_ | GePt3 · mC16 · C2/m (12) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–715.5 K, x(Si) 0.25–0.25 | 3 | 1 |
| [PT3SI_D011](#phase-pt-si-pt3si-d011); _phase:pt-si:pt3si-d011_ | Fe3C · D0_11 · oP16 · Pnma (62) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 715.5–1147.35 K, x(Si) 0.25–0.25 | 12 | 1 |
| [PT5SI2](#phase-pt-si-pt5si2); _phase:pt-si:pt5si2_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300–1141.18 K, x(Si) 0.286–0.286 | 2 | 1 |
| [PT6SI5](#phase-pt-si-pt6si5); _phase:pt-si:pt6si5_ | Pt6Si5 · mP22 · P2_1/m (11) | tier B: DFT-supported (unique MP + OQMD match) | stable in 1 of 1 calculated diagram(s): 300–1292.73 K, x(Si) 0.45455–0.45455 | 4 | 1 |
| [PTSI_B31](#phase-pt-si-ptsi-b31); _phase:pt-si:ptsi-b31_ | MnP · B31 · oP8 · Pnma (62) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1504.68 K, x(Si) 0.5–0.5 | 8 | 1 |

## DIAMOND_A4 (Pt–Si)

- Id: `phase:pt-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): 300–2499.68 K, x(Si) 1–1
- Literature: 3 values (3 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:a4-diamond)

Names (4): _corpus: _corpus:phase:pt-si:a4-diamond, corpus:phase:pt-si:diamond-a4  
_paper: _paper:10.1016/j.calphad.2007.07.010:Diamond(Si)  
_tdb: _tdb:PtSi-08Xu.tdb:DIAMOND_A4  


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

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): DIAMOND_A4, type code %, sha256 `10c16b80054347fb…`

~~~~text
41: PHASE DIAMOND_A4 % 1 1 !
42: CONST DIAMOND_A4 : SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## BCC_A2 (Pt–Si)

- Id: `phase:pt-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: not stable in 1 calculated diagram(s)
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:bcc-a2)

Names (2): _corpus: _corpus:phase:pt-si:bcc-a2  
_tdb: _tdb:PtSi-08Xu.tdb:BCC_A2  


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

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): BCC_A2, type code %B, sha256 `10c16b80054347fb…`

~~~~text
31: PHASE BCC_A2 %B 2 1 3 !
32: CONST BCC_A2 : PT SI : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase_

## FCC_A1 (Pt–Si)

- Id: `phase:pt-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: stable in 1 of 1 calculated diagram(s): 300–2063.01 K, x(Si) 0–0.01071
- Literature: 5 values (5 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:fcc-a1)

Names (3): _corpus: _corpus:phase:pt-si:fcc-a1  
_paper: _paper:10.1016/j.calphad.2007.07.010:Fcc(Pt)  
_tdb: _tdb:PtSi-08Xu.tdb:FCC_A1  


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

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): FCC_A1, type code %A, sha256 `10c16b80054347fb…`

~~~~text
26: PHASE FCC_A1 %A 2 1 1 !
27: CONST FCC_A1 : PT SI : VA : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## HCP_A3 (Pt–Si)

- Id: `phase:pt-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: not stable in 1 calculated diagram(s)
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:hcp-a3)

Names (2): _corpus: _corpus:phase:pt-si:hcp-a3  
_tdb: _tdb:PtSi-08Xu.tdb:HCP_A3  


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

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): HCP_A3, type code %A, sha256 `10c16b80054347fb…`

~~~~text
36: PHASE HCP_A3 %A 2 1 0.5 !
37: CONST HCP_A3 : PT SI : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase_

## LIQUID (Pt–Si)

- Id: `phase:pt-si:liquid`; status `assigned`
- Structure: liquid; type `st:liquid`; liquid; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 1124.26–2500 K, x(Si) 0–1
- Literature: 20 values (20 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:liquid)

Names (3): _corpus: _corpus:phase:pt-si:liquid  
_paper: _paper:10.1016/j.calphad.2007.07.010:L  
_tdb: _tdb:PtSi-08Xu.tdb:LIQUID  


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

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): LIQUID, type code %, sha256 `10c16b80054347fb…`

~~~~text
21: PHASE LIQUID:L % 1 1 !
22: CONST LIQUID:L : PT SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## PT17SI8_ALPHA (Pt–Si)

- Id: `phase:pt-si:pt17si8-alpha`; status `assigned`
- Structure: Pt12Si5 · tP68 · P4/n (85); type `st:pt12si5-tp68`; 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](https://doi.org/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: Pt 0.6800, Si 0.3200
- Stability: stable in 1 of 1 calculated diagram(s): 1042.99–1280 K, x(Si) 0.32–0.32
- Literature: 2 values (2 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:pt17si8-alpha)

Names (3): _corpus: _corpus:phase:pt-si:pt17si8-alpha  
_paper: _paper:10.1016/j.calphad.2007.07.010:α-Pt17Si8  
_tdb: _tdb:PtSi-08Xu.tdb:PT17SI8_ALPHA  


### TDB models of PT17SI8_ALPHA (1): PHASE and CONSTITUENT statements as written

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): PT17SI8_ALPHA, type code %, sha256 `10c16b80054347fb…`

~~~~text
66: PHASE PT17SI8_ALPHA % 2 17 8 !
67: CONST PT17SI8_ALPHA : PT : SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## PT17SI8_BETA (Pt–Si)

- Id: `phase:pt-si:pt17si8-beta`; status `assigned`
- Structure: Ni12P5 · tI34 · I4/m (87); type `st:ni12p5-ti34`; 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](https://doi.org/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: Pt 0.6800, Si 0.3200
- Stability: stable in 1 of 1 calculated diagram(s): 300–1042.99 K, x(Si) 0.32–0.32
- Literature: 8 values (8 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:pt17si8-beta)

Names (3): _corpus: _corpus:phase:pt-si:pt17si8-beta  
_paper: _paper:10.1016/j.calphad.2007.07.010:β-Pt17Si8  
_tdb: _tdb:PtSi-08Xu.tdb:PT17SI8_BETA  


### TDB models of PT17SI8_BETA (1): PHASE and CONSTITUENT statements as written

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): PT17SI8_BETA, type code %, sha256 `10c16b80054347fb…`

~~~~text
71: PHASE PT17SI8_BETA % 2 17 8 !
72: CONST PT17SI8_BETA : PT : SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## PT25SI7 (Pt–Si)

- Id: `phase:pt-si:pt25si7`; status `needs_review`
- No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
- Candidate (literature_printed): (Pt25Si7) · ? — printed with a label mapped to this phase
- Candidate (sgte_mmc2): (Pt25Si7) — Hallstedt 2025 mmc2 row for PT25SI7: Pt25Si7
- Stoichiometry: Pt 0.7820, Si 0.2180
- Stability: stable in 1 of 1 calculated diagram(s): 300–1115.4 K, x(Si) 0.218–0.218
- Literature: 2 values (2 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:pt25si7)

Names (3): _corpus: _corpus:phase:pt-si:pt25si7  
_paper: _paper:10.1016/j.calphad.2007.07.010:Pt25Si7  
_tdb: _tdb:PtSi-08Xu.tdb:PT25SI7  


### TDB models of PT25SI7 (1): PHASE and CONSTITUENT statements as written

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): PT25SI7, type code %, sha256 `10c16b80054347fb…`

~~~~text
46: PHASE PT25SI7 % 2 0.782 0.218 !
47: CONST PT25SI7 : PT : SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## PT2SI_C22 (Pt–Si)

- Id: `phase:pt-si:pt2si-c22`; status `assigned`
- Structure: Fe2P · C22 · hP9 · P-62m (189); type `st:c22-fe2p-hp9`; tier A: standard phase name; confidence high
- Stoichiometry: Pt 0.6667, Si 0.3333
- Stability: stable in 1 of 1 calculated diagram(s): 1017.54–1378.31 K, x(Si) 0.33333–0.33333
- Literature: 3 values (3 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:pt2si-c22)

Names (3): _corpus: _corpus:phase:pt-si:pt2si-c22  
_paper: _paper:10.1016/j.calphad.2007.07.010:α-Pt2Si  
_tdb: _tdb:PtSi-08Xu.tdb:PT2SI_C22  


### TDB models of PT2SI_C22 (1): PHASE and CONSTITUENT statements as written

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): PT2SI_C22, type code %, sha256 `10c16b80054347fb…`

~~~~text
76: PHASE PT2SI_C22 % 2 2 1 !
77: CONST PT2SI_C22 : PT : SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## PT2SI_L2B (Pt–Si)

- Id: `phase:pt-si:pt2si-l2b`; status `assigned`
- Structure: ThH2 · L'2_b · tI6 · I4/mmm (139); type `st:l-2-b-thh2-ti6`; 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](https://doi.org/10.1016/j.calphad.2025.102833)
- Caveat: not certain from the name or DFT alone (name_has_descriptive_tokens:L2B, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: Pt 0.6667, Si 0.3333
- Stability: stable in 1 of 1 calculated diagram(s): 323.56–1017.54 K, x(Si) 0.33333–0.33333
- Literature: 10 values (10 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:pt2si-l2b)

Names (3): _corpus: _corpus:phase:pt-si:pt2si-l2b  
_paper: _paper:10.1016/j.calphad.2007.07.010:β-Pt2Si  
_tdb: _tdb:PtSi-08Xu.tdb:PT2SI_L2B  


### TDB models of PT2SI_L2B (1): PHASE and CONSTITUENT statements as written

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): PT2SI_L2B, type code %, sha256 `10c16b80054347fb…`

~~~~text
81: PHASE PT2SI_L2B % 2 2 1 !
82: CONST PT2SI_L2B : PT : SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## PT3SI_ALPHA (Pt–Si)

- Id: `phase:pt-si:pt3si-alpha`; status `assigned`
- Structure: GePt3 · mC16 · C2/m (12); type `st:gept3-mc16`; 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](https://doi.org/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: Pt 0.7500, Si 0.2500
- Stability: stable in 1 of 1 calculated diagram(s): 300–715.5 K, x(Si) 0.25–0.25
- Literature: 3 values (3 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:pt3si-alpha)

Names (3): _corpus: _corpus:phase:pt-si:pt3si-alpha  
_paper: _paper:10.1016/j.calphad.2007.07.010:α-Pt3Si  
_tdb: _tdb:PtSi-08Xu.tdb:PT3SI_ALPHA  


### TDB models of PT3SI_ALPHA (1): PHASE and CONSTITUENT statements as written

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): PT3SI_ALPHA, type code %, sha256 `10c16b80054347fb…`

~~~~text
51: PHASE PT3SI_ALPHA % 2 3 1 !
52: CONST PT3SI_ALPHA : PT : SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## PT3SI_D011 (Pt–Si)

- Id: `phase:pt-si:pt3si-d011`; status `assigned`
- Structure: Fe3C · D0_11 · oP16 · Pnma (62); type `st:d0-11-fe3c-op16`; tier A: standard phase name; confidence high
- Stoichiometry: Pt 0.7500, Si 0.2500
- Stability: stable in 1 of 1 calculated diagram(s): 715.5–1147.35 K, x(Si) 0.25–0.25
- Literature: 12 values (12 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:pt3si-d011)

Names (3): _corpus: _corpus:phase:pt-si:pt3si-d011  
_paper: _paper:10.1016/j.calphad.2007.07.010:β-Pt3Si  
_tdb: _tdb:PtSi-08Xu.tdb:PT3SI_D011  


### TDB models of PT3SI_D011 (1): PHASE and CONSTITUENT statements as written

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): PT3SI_D011, type code %, sha256 `10c16b80054347fb…`

~~~~text
56: PHASE PT3SI_D011 % 2 3 1 !
57: CONST PT3SI_D011 : PT : SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## PT5SI2 (Pt–Si)

- Id: `phase:pt-si:pt5si2`; status `needs_review`
- No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
- Candidate (literature_printed): (Pt5Si2) · ? — printed with a label mapped to this phase
- Candidate (sgte_mmc2): (Pt5Si2) — Hallstedt 2025 mmc2 row for PT5SI2: Pt25Si7
- Stoichiometry: Pt 0.7140, Si 0.2860
- Stability: stable in 1 of 1 calculated diagram(s): 300–1141.18 K, x(Si) 0.286–0.286
- Literature: 2 values (2 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:pt5si2)

Names (3): _corpus: _corpus:phase:pt-si:pt5si2  
_paper: _paper:10.1016/j.calphad.2007.07.010:Pt5Si2  
_tdb: _tdb:PtSi-08Xu.tdb:PT5SI2  


### TDB models of PT5SI2 (1): PHASE and CONSTITUENT statements as written

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): PT5SI2, type code %, sha256 `10c16b80054347fb…`

~~~~text
61: PHASE PT5SI2 % 2 0.714 0.286 !
62: CONST PT5SI2 : PT : SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## PT6SI5 (Pt–Si)

- Id: `phase:pt-si:pt6si5`; status `assigned`
- Structure: Pt6Si5 · mP22 · P2_1/m (11); type `st:pt6si5-mp22`; tier B: DFT-supported (unique MP + OQMD match); confidence high
- Stoichiometry: Pt 0.5455, Si 0.4545
- Stability: stable in 1 of 1 calculated diagram(s): 300–1292.73 K, x(Si) 0.45455–0.45455
- Literature: 4 values (4 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:pt6si5)

Names (5): _corpus: _corpus:phase:pt-si:pt6si5  
_mp: _mp:mp-aaaabrwv  
_oqmd: _oqmd:oqmd-8038  
_paper: _paper:10.1016/j.calphad.2007.07.010:Pt6Si5  
_tdb: _tdb:PtSi-08Xu.tdb:PT6SI5  


### TDB models of PT6SI5 (1): PHASE and CONSTITUENT statements as written

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): PT6SI5, type code %, sha256 `10c16b80054347fb…`

~~~~text
86: PHASE PT6SI5 % 2 6 5 !
87: CONST PT6SI5 : PT : SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of values for this phase_

## PTSI_B31 (Pt–Si)

- Id: `phase:pt-si:ptsi-b31`; status `assigned`
- Structure: MnP · B31 · oP8 · Pnma (62); type `st:b31-mnp-op8`; tier A: standard phase name; confidence high
- Caveat: DFT agrees: on-hull mp-aaaaabau and oqmd-2257, space group 62
- Stoichiometry: Pt 0.5000, Si 0.5000
- Stability: stable in 1 of 1 calculated diagram(s): 300–1504.68 K, x(Si) 0.5–0.5
- Literature: 8 values (8 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pt-si:ptsi-b31)

Names (5): _corpus: _corpus:phase:pt-si:ptsi-b31  
_mp: _mp:mp-aaaaabau  
_oqmd: _oqmd:oqmd-2257  
_paper: _paper:10.1016/j.calphad.2007.07.010:PtSi  
_tdb: _tdb:PtSi-08Xu.tdb:PTSI_B31  


### TDB models of PTSI_B31 (1): PHASE and CONSTITUENT statements as written

[PtSi-08Xu.tdb](https://orchid-project.org/data/databases/sgte-binary/PtSi-08Xu.tdb): PTSI_B31, type code %, sha256 `10c16b80054347fb…`

~~~~text
92: PHASE PTSI_B31 % 2 1 1 !
93: CONST PTSI_B31 : PT : SI : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.calphad.2007.07.010](https://doi.org/10.1016/j.calphad.2007.07.010) L.L. Xu, J. Wang, H.S. Liu, Z.P. Jin, Thermodynamic assessment of the Pt–Si binary system, Calphad 32, 101-105 (2008).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0925-8388(93)90888-t](https://doi.org/10.1016/0925-8388%2893%2990888-t) R. Massara, P. Feschotte, Le système binaire PtSi, Journal of Alloys and Compounds 201, 223-227 (1993).  
_cited as the source of 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). https://doi.org/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). https://doi.org/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.

```bibtex
@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}
}
```

---

Derived data CC BY 4.0 ([licence](https://creativecommons.org/licenses/by/4.0/)): cite the ORCHID phase registry and the sources named on the page (TDB assessments, Hallstedt 2025, Materials Project, OQMD). TDB statements are quoted as written; parameter expressions are not reproduced. Field reference: [SCHEMA.md](https://data.orchid-project.org/phases/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt).