# Co–Pr phases

> Co–Pr system: 14 phases (tier A 7, tier C 3, liquid 1, needs_review 3); 14 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/CO-PR.html · Markdown: https://data.orchid-project.org/phases/pages/CO-PR.md

14 phases (tier A 7, tier C 3, liquid 1, needs_review 3); 14 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=CO-PR) · [full JSON](https://data.orchid-project.org/phases/systems/CO-PR.json) · [Co–Pr system page](https://data.orchid-project.org/systems/CO-PR.html) · [Markdown](https://data.orchid-project.org/phases/pages/CO-PR.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md)

Table: Phases of the Co–Pr system (14)

| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---:|---:|
| [BCC_A2](#phase-co-pr-bcc-a2); _phase:co-pr:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 1068–2499.25 K, x(Pr) 0.93–1 | 0 | 1 |
| [CO17PR2](#phase-co-pr-co17pr2); _phase:co-pr:co17pr2_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 1158.52–1538.17 K, x(Pr) 0.10526–0.10526 | 10 | 1 |
| [CO19PR5](#phase-co-pr-co19pr5); _phase:co-pr:co19pr5_ | Ce5Co19 · hR24 · R-3m (166) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1399.79 K, x(Pr) 0.20833–0.20833 | 11 | 1 |
| [CO2PR_C15](#phase-co-pr-co2pr-c15); _phase:co-pr:co2pr-c15_ | Cu2Mg · C15 · cF24 · Fd-3m (227) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1210.04 K, x(Pr) 0.33333–0.33333 | 6 | 1 |
| [CO2PR5](#phase-co-pr-co2pr5); _phase:co-pr:co2pr5_ | Mn5C2 · mC28 · C2/c (15) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–816.95 K, x(Pr) 0.71429–0.71429 | 5 | 1 |
| [CO3PR](#phase-co-pr-co3pr); _phase:co-pr:co3pr_ | Ni3Pu · hR12 · R-3m (166) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1338.03 K, x(Pr) 0.25–0.25 | 6 | 1 |
| [CO3PR4](#phase-co-pr-co3pr4); _phase:co-pr:co3pr4_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300–861.23 K, x(Pr) 0.57143–0.57143 | 6 | 1 |
| [CO5PR_D2D](#phase-co-pr-co5pr-d2d); _phase:co-pr:co5pr-d2d_ | CaCu5 · D2_d · hP6 · P6/mmm (191) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 1135.38–1504.72 K, x(Pr) 0.16667–0.16667 | 11 | 1 |
| [CO7PR2](#phase-co-pr-co7pr2); _phase:co-pr:co7pr2_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300–1391.34 K, x(Pr) 0.22222–0.22222 | 6 | 1 |
| [COPR3_D011](#phase-co-pr-copr3-d011); _phase:co-pr:copr3-d011_ | Fe3C · D0_11 · oP16 · Pnma (62) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–851.95 K, x(Pr) 0.75–0.75 | 8 | 1 |
| [DHCP](#phase-co-pr-dhcp-a3); _phase:co-pr:dhcp-a3_ | alpha-La · A3' · hP4 · P6_3/mmc (194) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1203 K, x(Pr) 1–1 | 3 | 1 |
| [FCC_A1](#phase-co-pr-fcc-a1); _phase:co-pr:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 694.99–1789.88 K, x(Pr) 0–1e-05 | 2 | 1 |
| [HCP_A3](#phase-co-pr-hcp-a3); _phase:co-pr:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–694.99 K, x(Pr) 0–0 | 0 | 1 |
| [LIQUID](#phase-co-pr-liquid); _phase:co-pr:liquid_ | liquid | liquid | stable in 1 of 1 calculated diagram(s): 806.11–2500 K, x(Pr) 0–1 | 31 | 1 |

## BCC_A2 (Co–Pr)

- Id: `phase:co-pr: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): 1068–2499.25 K, x(Pr) 0.93–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:bcc-a2)

Names (2): _corpus: _corpus:phase:co-pr:bcc-a2  
_tdb: _tdb:CoPr-99Du.tdb:BCC_A2  


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

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): BCC_A2, type code %B, sha256 `2191eecdf8154a45…`

~~~~text
34: PHASE BCC_A2 %B 2 1 3 !
35: CONST BCC_A2 : CO PR% : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase_

## CO17PR2 (Co–Pr)

- Id: `phase:co-pr:co17pr2`; status `needs_review`
- No structure assigned. Why: no_structure_token; sgte_mmc2_row_disagrees_with_dft; sgte_mmc2_rows_disagree
- Candidate (dft_mp): R-3m (166) — on-hull MP Pr2Co17 at x(PR)=0.1053
- Candidate (dft_oqmd): R-3m (166) — on-hull OQMD Co17 Pr2 at x(PR)=0.1053
- Candidate (literature_printed): Ni17Th2 · hP38 — printed with a label mapped to this phase
- Candidate (sgte_mmc2): Ni17Th2 · hP38 · P6_3/mmc (194) — Hallstedt 2025 mmc2 row for CO17PR2: Co17Pr2 (high T), see also Th2Zn17
- Candidate (sgte_mmc2): Th2Zn17 · hR19 · R-3m (166) — Hallstedt 2025 mmc2 row for CO17PR2: Co17Pr2 (low T), see also Ni17Th2
- Candidate (tdb_comment): Ni17Th2 · hP38 · P6_3/mmc, ht — CoPr-99Du.tdb: 'Prototype Ni17Th2 (hP38, P6_3/mmc, ht) and Th2Zn17 (hR19, R-3m, lt)'
- Stoichiometry: Co 0.8947, Pr 0.1053
- Stability: stable in 1 of 1 calculated diagram(s): 1158.52–1538.17 K, x(Pr) 0.10526–0.10526
- Literature: 10 values (6 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:co17pr2)

Names (3): _corpus: _corpus:phase:co-pr:co17pr2  
_paper: _paper:10.1016/s0925-8388(98)00928-1:Co17Pr2  
_tdb: _tdb:CoPr-99Du.tdb:CO17PR2  


### TDB models of CO17PR2 (1): PHASE and CONSTITUENT statements as written

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): CO17PR2, type code %A, sha256 `2191eecdf8154a45…`

~~~~text
49: PHASE CO17PR2 %A 2 17 2 !
50: CONST CO17PR2 : CO : PR : !
~~~~

Example references (3 of 3; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(72)90115-4](https://doi.org/10.1016/0022-5088%2872%2990115-4) K.H.J. Buschow, Note on the stability of rare earth-cobalt compounds with CaCu5 structure, Journal of the Less Common Metals 29, 283-288 (1972).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(86)90077-9](https://doi.org/10.1016/0022-5088%2886%2990077-9) Y.C. Chuang, C.H. Wu, S.C. Chang, T.C. Li, Y.C. Wang, Effect of heat treatment on the microstructure and coercivity of PrCo5, Journal of the Less Common Metals 125, 25-32 (1986).  
_cited as the source of values for this phase_

## CO19PR5 (Co–Pr)

- Id: `phase:co-pr:co19pr5`; status `assigned`
- Structure: Ce5Co19 · hR24 · R-3m (166); type `st:ce5co19-hr24`; 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_on_hull_entry_in_both, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: Co 0.7917, Pr 0.2083
- Stability: stable in 1 of 1 calculated diagram(s): 300–1399.79 K, x(Pr) 0.20833–0.20833
- Literature: 11 values (7 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:co19pr5)

Names (3): _corpus: _corpus:phase:co-pr:co19pr5  
_paper: _paper:10.1016/s0925-8388(98)00928-1:Co19Pr5  
_tdb: _tdb:CoPr-99Du.tdb:CO19PR5  


### TDB models of CO19PR5 (1): PHASE and CONSTITUENT statements as written

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): CO19PR5, type code %A, sha256 `2191eecdf8154a45…`

~~~~text
59: PHASE CO19PR5 %A 2 19 5 !
60: CONST CO19PR5 : CO : PR : !
~~~~

Example references (3 of 3; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(72)90115-4](https://doi.org/10.1016/0022-5088%2872%2990115-4) K.H.J. Buschow, Note on the stability of rare earth-cobalt compounds with CaCu5 structure, Journal of the Less Common Metals 29, 283-288 (1972).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(86)90077-9](https://doi.org/10.1016/0022-5088%2886%2990077-9) Y.C. Chuang, C.H. Wu, S.C. Chang, T.C. Li, Y.C. Wang, Effect of heat treatment on the microstructure and coercivity of PrCo5, Journal of the Less Common Metals 125, 25-32 (1986).  
_cited as the source of values for this phase_

## CO2PR_C15 (Co–Pr)

- Id: `phase:co-pr:co2pr-c15`; status `assigned`
- Structure: Cu2Mg · C15 · cF24 · Fd-3m (227); type `st:c15-cu2mg-cf24`; tier A: standard phase name; confidence high
- Stoichiometry: Co 0.6667, Pr 0.3333
- Stability: stable in 1 of 1 calculated diagram(s): 300–1210.04 K, x(Pr) 0.33333–0.33333
- Literature: 6 values (6 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:co2pr-c15)

Names (3): _corpus: _corpus:phase:co-pr:co2pr-c15  
_paper: _paper:10.1016/s0925-8388(98)00928-1:Co2Pr  
_tdb: _tdb:CoPr-99Du.tdb:CO2PR_C15  


### TDB models of CO2PR_C15 (1): PHASE and CONSTITUENT statements as written

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): CO2PR_C15, type code %A, sha256 `2191eecdf8154a45…`

~~~~text
74: PHASE CO2PR_C15 %A 2 2 1 !
75: CONST CO2PR_C15 : CO : PR : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase; reports values for this phase_

## CO2PR5 (Co–Pr)

- Id: `phase:co-pr:co2pr5`; status `assigned`
- Structure: Mn5C2 · mC28 · C2/c (15); type `st:mn5c2-mc28`; 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_15_matches_2_structure_types, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: Co 0.2857, Pr 0.7143
- Stability: stable in 1 of 1 calculated diagram(s): 300–816.95 K, x(Pr) 0.71429–0.71429
- Literature: 5 values (5 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:co2pr5)

Names (3): _corpus: _corpus:phase:co-pr:co2pr5  
_paper: _paper:10.1016/s0925-8388(98)00928-1:Co2Pr5  
_tdb: _tdb:CoPr-99Du.tdb:CO2PR5  


### TDB models of CO2PR5 (1): PHASE and CONSTITUENT statements as written

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): CO2PR5, type code %, sha256 `2191eecdf8154a45…`

~~~~text
84: PHASE CO2PR5 % 2 2 5 !
85: CONST CO2PR5 : CO : PR : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase; reports values for this phase_

## CO3PR (Co–Pr)

- Id: `phase:co-pr:co3pr`; status `assigned`
- Structure: Ni3Pu · hR12 · R-3m (166); type `st:ni3pu-hr12`; 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_on_hull_entry_in_both, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: Co 0.7500, Pr 0.2500
- Stability: stable in 1 of 1 calculated diagram(s): 300–1338.03 K, x(Pr) 0.25–0.25
- Literature: 6 values (6 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:co3pr)

Names (3): _corpus: _corpus:phase:co-pr:co3pr  
_paper: _paper:10.1016/s0925-8388(98)00928-1:Co3Pr  
_tdb: _tdb:CoPr-99Du.tdb:CO3PR  


### TDB models of CO3PR (1): PHASE and CONSTITUENT statements as written

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): CO3PR, type code %A, sha256 `2191eecdf8154a45…`

~~~~text
69: PHASE CO3PR %A 2 3 1 !
70: CONST CO3PR : CO : PR : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase; reports values for this phase_

## CO3PR4 (Co–Pr)

- Id: `phase:co-pr:co3pr4`; status `needs_review`
- No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
- Candidate (literature_printed): (Co3Pr4) · hP\* — printed with a label mapped to this phase
- Candidate (sgte_mmc2): (Co3Pr4) — Hallstedt 2025 mmc2 row for CO3PR4: Co3Pr4
- Stoichiometry: Co 0.4286, Pr 0.5714
- Stability: stable in 1 of 1 calculated diagram(s): 300–861.23 K, x(Pr) 0.57143–0.57143
- Literature: 6 values (6 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:co3pr4)

Names (3): _corpus: _corpus:phase:co-pr:co3pr4  
_paper: _paper:10.1016/s0925-8388(98)00928-1:Co3Pr4  
_tdb: _tdb:CoPr-99Du.tdb:CO3PR4  


### TDB models of CO3PR4 (1): PHASE and CONSTITUENT statements as written

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): CO3PR4, type code %, sha256 `2191eecdf8154a45…`

~~~~text
79: PHASE CO3PR4 % 2 3 4 !
80: CONST CO3PR4 : CO : PR : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase; reports values for this phase_

## CO5PR_D2D (Co–Pr)

- Id: `phase:co-pr:co5pr-d2d`; status `assigned`
- Structure: CaCu5 · D2_d · hP6 · P6/mmm (191); type `st:d2-d-cacu5-hp6`; tier A: standard phase name; confidence high
- Stoichiometry: Co 0.8333, Pr 0.1667
- Stability: stable in 1 of 1 calculated diagram(s): 1135.38–1504.72 K, x(Pr) 0.16667–0.16667
- Literature: 11 values (7 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:co5pr-d2d)

Names (3): _corpus: _corpus:phase:co-pr:co5pr-d2d  
_paper: _paper:10.1016/s0925-8388(98)00928-1:Co5Pr  
_tdb: _tdb:CoPr-99Du.tdb:CO5PR_D2D  


### TDB models of CO5PR_D2D (1): PHASE and CONSTITUENT statements as written

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): CO5PR_D2D, type code %A, sha256 `2191eecdf8154a45…`

~~~~text
54: PHASE CO5PR_D2D %A 2 5 1 !
55: CONST CO5PR_D2D : CO : PR : !
~~~~

Example references (3 of 3; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(72)90115-4](https://doi.org/10.1016/0022-5088%2872%2990115-4) K.H.J. Buschow, Note on the stability of rare earth-cobalt compounds with CaCu5 structure, Journal of the Less Common Metals 29, 283-288 (1972).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(86)90077-9](https://doi.org/10.1016/0022-5088%2886%2990077-9) Y.C. Chuang, C.H. Wu, S.C. Chang, T.C. Li, Y.C. Wang, Effect of heat treatment on the microstructure and coercivity of PrCo5, Journal of the Less Common Metals 125, 25-32 (1986).  
_cited as the source of values for this phase_

## CO7PR2 (Co–Pr)

- Id: `phase:co-pr:co7pr2`; status `needs_review`
- No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_rows_disagree
- Candidate (literature_printed): Ce2Ni7 · hP36 — printed with a label mapped to this phase
- Candidate (sgte_mmc2): Ce2Ni7 · hP36 · P6_3/mmc (194) — Hallstedt 2025 mmc2 row for CO7PR2: Co7Pr2 (high T), see also Co7Gd2
- Candidate (sgte_mmc2): Co7Gd2 · hR18 · R-3m (166) — Hallstedt 2025 mmc2 row for CO7PR2: Co7Pr2 (low T), see also Ce2Ni7
- Candidate (tdb_comment): Ce2Ni7 · hP36 · P6_3/mmc, ht — CoPr-99Du.tdb: 'Prototype Ce2Ni7 (hP36, P6_3/mmc, ht) and Co7Gd2 (hR18, R-3m, lt)'
- Stoichiometry: Co 0.7778, Pr 0.2222
- Stability: stable in 1 of 1 calculated diagram(s): 300–1391.34 K, x(Pr) 0.22222–0.22222
- Literature: 6 values (6 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:co7pr2)

Names (3): _corpus: _corpus:phase:co-pr:co7pr2  
_paper: _paper:10.1016/s0925-8388(98)00928-1:Co7Pr2  
_tdb: _tdb:CoPr-99Du.tdb:CO7PR2  


### TDB models of CO7PR2 (1): PHASE and CONSTITUENT statements as written

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): CO7PR2, type code %A, sha256 `2191eecdf8154a45…`

~~~~text
64: PHASE CO7PR2 %A 2 7 2 !
65: CONST CO7PR2 : CO : PR : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase; reports values for this phase_

## COPR3_D011 (Co–Pr)

- Id: `phase:co-pr:copr3-d011`; status `assigned`
- Structure: Fe3C · D0_11 · oP16 · Pnma (62); type `st:d0-11-fe3c-op16`; tier A: standard phase name; confidence high
- Caveat: DFT agrees: on-hull mp-aaabxche and oqmd-663801, space group 62
- Stoichiometry: Co 0.2500, Pr 0.7500
- Stability: stable in 1 of 1 calculated diagram(s): 300–851.95 K, x(Pr) 0.75–0.75
- Literature: 8 values (8 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:copr3-d011)

Names (5): _corpus: _corpus:phase:co-pr:copr3-d011  
_mp: _mp:mp-aaabxche  
_oqmd: _oqmd:oqmd-663801  
_paper: _paper:10.1016/s0925-8388(98)00928-1:CoPr3  
_tdb: _tdb:CoPr-99Du.tdb:COPR3_D011  


### TDB models of COPR3_D011 (1): PHASE and CONSTITUENT statements as written

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): COPR3_D011, type code %, sha256 `2191eecdf8154a45…`

~~~~text
89: PHASE COPR3_D011 % 2 1 3 !
90: CONST COPR3_D011 : CO : PR : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase; reports values for this phase_

## DHCP (Co–Pr)

- Id: `phase:co-pr:dhcp-a3`; status `assigned`
- Structure: alpha-La · A3' · hP4 · P6_3/mmc (194); type `st:a3-alpha-la-hp4`; tier A: standard phase name; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 300–1203 K, x(Pr) 1–1
- Literature: 3 values (3 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:dhcp-a3)

Names (4): _corpus: _corpus:phase:co-pr:dhcp-a3, corpus:phase:co-pr:dhcp  
_paper: _paper:10.1016/s0925-8388(98)00928-1:dhcp(Pr)  
_tdb: _tdb:CoPr-99Du.tdb:DHCP  


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

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): DHCP, type code %, sha256 `2191eecdf8154a45…`

~~~~text
44: PHASE DHCP % 1 1 !
45: CONST DHCP : CO PR% : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase; reports values for this phase_

## FCC_A1 (Co–Pr)

- Id: `phase:co-pr: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): 694.99–1789.88 K, x(Pr) 0–1e-05
- Literature: 2 values (2 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:fcc-a1)

Names (3): _corpus: _corpus:phase:co-pr:fcc-a1  
_paper: _paper:10.1016/s0925-8388(98)00928-1:fcc(Co)  
_tdb: _tdb:CoPr-99Du.tdb:FCC_A1  


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

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): FCC_A1, type code %A, sha256 `2191eecdf8154a45…`

~~~~text
29: PHASE FCC_A1 %A 2 1 1 !
30: CONST FCC_A1 : CO% PR : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase; reports values for this phase_

## HCP_A3 (Co–Pr)

- Id: `phase:co-pr: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): 300–694.99 K, x(Pr) 0–0
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:hcp-a3)

Names (2): _corpus: _corpus:phase:co-pr:hcp-a3  
_tdb: _tdb:CoPr-99Du.tdb:HCP_A3  


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

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): HCP_A3, type code %A, sha256 `2191eecdf8154a45…`

~~~~text
39: PHASE HCP_A3 %A 2 1 0.5 !
40: CONST HCP_A3 : CO% PR : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_assessment that models this phase_

## LIQUID (Co–Pr)

- Id: `phase:co-pr:liquid`; status `assigned`
- Structure: liquid; type `st:liquid`; liquid; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 806.11–2500 K, x(Pr) 0–1
- Literature: 31 values (31 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:co-pr:liquid)

Names (3): _corpus: _corpus:phase:co-pr:liquid  
_paper: _paper:10.1016/s0925-8388(98)00928-1:liq.  
_tdb: _tdb:CoPr-99Du.tdb:LIQUID  


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

[CoPr-99Du.tdb](https://orchid-project.org/data/databases/sgte-binary/CoPr-99Du.tdb): LIQUID, type code %, sha256 `2191eecdf8154a45…`

~~~~text
24: PHASE LIQUID:L % 1 1 !
25: CONST LIQUID:L : CO PR : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/S0925-8388(98)00928-1](https://doi.org/10.1016/S0925-8388%2898%2900928-1) Z. Du, D. Wang, W. Zhang, J. Alloys Compd., 284, 206-12(1999).  
_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). 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).