# Pd–Sc phases

> Pd–Sc system: 9 phases (tier A 5, tier C 1, liquid 1, needs_review 2); 9 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/PD-SC.html · Markdown: https://data.orchid-project.org/phases/pages/PD-SC.md

9 phases (tier A 5, 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](https://orchid-project.org/phases/?q=PD-SC) · [full JSON](https://data.orchid-project.org/phases/systems/PD-SC.json) · [Pd–Sc system page](https://data.orchid-project.org/systems/PD-SC.html) · [Markdown](https://data.orchid-project.org/phases/pages/PD-SC.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md)

Table: Phases of the Pd–Sc system (9)

| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---:|---:|
| [BCC_A2](#phase-pd-sc-bcc-a2); _phase:pd-sc:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300.5–2499.25 K, x(Sc) 1–1 | 0 | 1 |
| [FCC_A1](#phase-pd-sc-fcc-a1); _phase:pd-sc:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1829.3 K, x(Sc) 0–0.14915 | 0 | 1 |
| [HCP_A3](#phase-pd-sc-hcp-a3); _phase:pd-sc:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1608 K, x(Sc) 1–1 | 0 | 1 |
| [LIQUID](#phase-pd-sc-liquid); _phase:pd-sc:liquid_ | liquid | liquid | stable in 1 of 1 calculated diagram(s): 1273.15–2500 K, x(Sc) 0–1 | 0 | 1 |
| [PD2SC](#phase-pd-sc-pd2sc); _phase:pd-sc:pd2sc_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300–1702.45 K, x(Sc) 0.33333–0.33333 | 3 | 1 |
| [PD3SC_L12](#phase-pd-sc-pd3sc-l12); _phase:pd-sc:pd3sc-l12_ | AuCu3 · L1_2 · cP4 · Pm-3m (221) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1772.45 K, x(Sc) 0.25–0.25 | 0 | 1 |
| [PDSC_B2](#phase-pd-sc-pdsc-b2); _phase:pd-sc:pdsc-b2_ | CsCl · B2 · cP2 · Pm-3m (221) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1872.38 K, x(Sc) 0.5–0.50869 | 0 | 1 |
| [PDSC2](#phase-pd-sc-pdsc2); _phase:pd-sc:pdsc2_ | NiTi2 · cF96 · Fd-3m (227) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1472.82 K, x(Sc) 0.66667–0.66667 | 0 | 1 |
| [PDSC4](#phase-pd-sc-pdsc4); _phase:pd-sc:pdsc4_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300–1312.84 K, x(Sc) 0.8–0.8 | 0 | 1 |

## BCC_A2 (Pd–Sc)

- Id: `phase:pd-sc: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): 300.5–2499.25 K, x(Sc) 1–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-sc:bcc-a2)

Names (2): _corpus: _corpus:phase:pd-sc:bcc-a2  
_tdb: _tdb:PdSc-02Du.tdb:BCC_A2  


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

[PdSc-02Du.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSc-02Du.tdb): BCC_A2, type code %B, sha256 `63a13cc650067f3a…`

~~~~text
34: PHASE BCC_A2 %B 2 1 3 !
35: CONST BCC_A2 : PD SC% : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.3139/146.020277](https://doi.org/10.3139/146.020277) Z. Du, C. Li, L. Lu, Z. Metallkd., 93, 277-80(2002).  
_assessment that models this phase_

## FCC_A1 (Pd–Sc)

- Id: `phase:pd-sc: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): 300–1829.3 K, x(Sc) 0–0.14915
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-sc:fcc-a1)

Names (2): _corpus: _corpus:phase:pd-sc:fcc-a1  
_tdb: _tdb:PdSc-02Du.tdb:FCC_A1  


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

[PdSc-02Du.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSc-02Du.tdb): FCC_A1, type code %A, sha256 `63a13cc650067f3a…`

~~~~text
29: PHASE FCC_A1 %A 2 1 1 !
30: CONST FCC_A1 : PD% SC : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.3139/146.020277](https://doi.org/10.3139/146.020277) Z. Du, C. Li, L. Lu, Z. Metallkd., 93, 277-80(2002).  
_assessment that models this phase_

## HCP_A3 (Pd–Sc)

- Id: `phase:pd-sc: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): 300–1608 K, x(Sc) 1–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-sc:hcp-a3)

Names (2): _corpus: _corpus:phase:pd-sc:hcp-a3  
_tdb: _tdb:PdSc-02Du.tdb:HCP_A3  


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

[PdSc-02Du.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSc-02Du.tdb): HCP_A3, type code %A, sha256 `63a13cc650067f3a…`

~~~~text
39: PHASE HCP_A3 %A 2 1 0.5 !
40: CONST HCP_A3 : PD SC% : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.3139/146.020277](https://doi.org/10.3139/146.020277) Z. Du, C. Li, L. Lu, Z. Metallkd., 93, 277-80(2002).  
_assessment that models this phase_

## LIQUID (Pd–Sc)

- Id: `phase:pd-sc:liquid`; status `assigned`
- Structure: liquid; type `st:liquid`; liquid; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 1273.15–2500 K, x(Sc) 0–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-sc:liquid)

Names (2): _corpus: _corpus:phase:pd-sc:liquid  
_tdb: _tdb:PdSc-02Du.tdb:LIQUID  


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

[PdSc-02Du.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSc-02Du.tdb): LIQUID, type code %, sha256 `63a13cc650067f3a…`

~~~~text
24: PHASE LIQUID:L % 1 1 !
25: CONST LIQUID:L : PD SC : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.3139/146.020277](https://doi.org/10.3139/146.020277) Z. Du, C. Li, L. Lu, Z. Metallkd., 93, 277-80(2002).  
_assessment that models this phase_

## PD2SC (Pd–Sc)

- Id: `phase:pd-sc:pd2sc`; status `needs_review`
- No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
- Candidate (sgte_mmc2): (Pd2Sc) — Hallstedt 2025 mmc2 row for PD2SC: Pd2Sc
- Stoichiometry: Pd 0.6667, Sc 0.3333
- Stability: stable in 1 of 1 calculated diagram(s): 300–1702.45 K, x(Sc) 0.33333–0.33333
- Literature: 3 values (3 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-sc:pd2sc)

Names (3): _corpus: _corpus:phase:pd-sc:pd2sc  
_paper: _paper:10.1016/j.matpr.2019.08.196:Pd2Sc  
_tdb: _tdb:PdSc-02Du.tdb:PD2SC  


### TDB models of PD2SC (1): PHASE and CONSTITUENT statements as written

[PdSc-02Du.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSc-02Du.tdb): PD2SC, type code %, sha256 `63a13cc650067f3a…`

~~~~text
49: PHASE PD2SC % 2 2 1 !
50: CONST PD2SC : PD : SC : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.3139/146.020277](https://doi.org/10.3139/146.020277) Z. Du, C. Li, L. Lu, Z. Metallkd., 93, 277-80(2002).  
_assessment that models this phase_
- [doi:10.1016/j.matpr.2019.08.196](https://doi.org/10.1016/j.matpr.2019.08.196) Said Kardellass, Colette Servant, Isabelle Drouelle, Fatima Zahra Chrifi-Alaoui, Mohamed Idbenali, Alyen Abahazem et al., Calphad-type assessment of the Pd-Yb binary system supported by first-principles calculations – Part II: Results, Materials Today: Proceedings 24, 140-150 (2020).  
_reports values for this phase_

## PD3SC_L12 (Pd–Sc)

- Id: `phase:pd-sc:pd3sc-l12`; status `assigned`
- Structure: AuCu3 · L1_2 · cP4 · Pm-3m (221); type `st:l1-2-aucu3-cp4`; tier A: standard phase name; confidence high
- Caveat: DFT agrees: on-hull mp-aaaaadyz and oqmd-17945, space group 221
- Stoichiometry: Pd 0.7500, Sc 0.2500
- Stability: stable in 1 of 1 calculated diagram(s): 300–1772.45 K, x(Sc) 0.25–0.25
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-sc:pd3sc-l12)

Names (4): _corpus: _corpus:phase:pd-sc:pd3sc-l12  
_mp: _mp:mp-aaaaadyz  
_oqmd: _oqmd:oqmd-17945  
_tdb: _tdb:PdSc-02Du.tdb:PD3SC_L12  


### TDB models of PD3SC_L12 (1): PHASE and CONSTITUENT statements as written

[PdSc-02Du.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSc-02Du.tdb): PD3SC_L12, type code %, sha256 `63a13cc650067f3a…`

~~~~text
44: PHASE PD3SC_L12 % 2 3 1 !
45: CONST PD3SC_L12 : PD : SC : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.3139/146.020277](https://doi.org/10.3139/146.020277) Z. Du, C. Li, L. Lu, Z. Metallkd., 93, 277-80(2002).  
_assessment that models this phase_

## PDSC_B2 (Pd–Sc)

- Id: `phase:pd-sc:pdsc-b2`; status `assigned`
- Structure: CsCl · B2 · cP2 · Pm-3m (221); type `st:b2-cscl-cp2`; tier A: standard phase name; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 300–1872.38 K, x(Sc) 0.5–0.50869
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-sc:pdsc-b2)

Names (2): _corpus: _corpus:phase:pd-sc:pdsc-b2  
_tdb: _tdb:PdSc-02Du.tdb:PDSC_B2  


### TDB models of PDSC_B2 (1): PHASE and CONSTITUENT statements as written

[PdSc-02Du.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSc-02Du.tdb): PDSC_B2, type code %, sha256 `63a13cc650067f3a…`

~~~~text
54: PHASE PDSC_B2 % 2 1 1 !
55: CONST PDSC_B2 : PD% VA : SC : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.3139/146.020277](https://doi.org/10.3139/146.020277) Z. Du, C. Li, L. Lu, Z. Metallkd., 93, 277-80(2002).  
_assessment that models this phase_

## PDSC2 (Pd–Sc)

- Id: `phase:pd-sc:pdsc2`; status `assigned`
- Structure: NiTi2 · cF96 · Fd-3m (227); type `st:niti2-cf96`; 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 (dft_space_group_227_matches_4_structure_types, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: Pd 0.3333, Sc 0.6667
- Stability: stable in 1 of 1 calculated diagram(s): 300–1472.82 K, x(Sc) 0.66667–0.66667
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-sc:pdsc2)

Names (2): _corpus: _corpus:phase:pd-sc:pdsc2  
_tdb: _tdb:PdSc-02Du.tdb:PDSC2  


### TDB models of PDSC2 (1): PHASE and CONSTITUENT statements as written

[PdSc-02Du.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSc-02Du.tdb): PDSC2, type code %, sha256 `63a13cc650067f3a…`

~~~~text
59: PHASE PDSC2 % 2 1 2 !
60: CONST PDSC2 : PD : SC : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.3139/146.020277](https://doi.org/10.3139/146.020277) Z. Du, C. Li, L. Lu, Z. Metallkd., 93, 277-80(2002).  
_assessment that models this phase_

## PDSC4 (Pd–Sc)

- Id: `phase:pd-sc:pdsc4`; status `needs_review`
- No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
- Candidate (sgte_mmc2): (PdSc4) — Hallstedt 2025 mmc2 row for PDSC4: PdSc4
- Stoichiometry: Pd 0.2000, Sc 0.8000
- Stability: stable in 1 of 1 calculated diagram(s): 300–1312.84 K, x(Sc) 0.8–0.8
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-sc:pdsc4)

Names (2): _corpus: _corpus:phase:pd-sc:pdsc4  
_tdb: _tdb:PdSc-02Du.tdb:PDSC4  


### TDB models of PDSC4 (1): PHASE and CONSTITUENT statements as written

[PdSc-02Du.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSc-02Du.tdb): PDSC4, type code %, sha256 `63a13cc650067f3a…`

~~~~text
64: PHASE PDSC4 % 2 1 4 !
65: CONST PDSC4 : PD : SC : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.3139/146.020277](https://doi.org/10.3139/146.020277) Z. Du, C. Li, L. Lu, Z. Metallkd., 93, 277-80(2002).  
_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). 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).