# Pr system > Pr system: 10 accepted literature values (crystal structure 7, phase transition 3) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote. HTML: https://data.orchid-project.org/systems/PR.html · Markdown: https://data.orchid-project.org/systems/PR.md 10 accepted literature values from 3 paper(s) (experimental 3, model 3, unspecified 4); 0 calculated phase diagram(s). Data: [JSON](https://data.orchid-project.org/literature/systems/PR.json) · [CSV](https://data.orchid-project.org/systems/PR.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#PR) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/PR.html) · [Markdown](https://data.orchid-project.org/systems/PR.md) Table: Accepted values by evidence class | Evidence class | Values | |---|---:| | experimental | 3 | | model | 3 | | unspecified | 4 | Table: Accepted values by property group | Property group | Values | |---|---:| | phase transition | 3 | | crystal structure | 7 | ## Other properties ### Phase transition (3) Table: Phase transition, Pr system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Phase transition | 1068 K | 1068 | polymorphic: Pr; _alloy: Pr 1_ | model | [1] Norgren 2000; _cites Saunders 1998_ | Table 1, p. 4, row 4; `ORC-NEDKG3TBPG` | | | Phase transition | 1068 K | 1068 | polymorphic: Pr; _alloy: Pr 1_ | model | [1] Norgren 2000; _cites Norgren_ | Table 1, p. 4, row 3; `ORC-QBJ3L6JPWB` | | | Phase transition | 1073 K | 1073 | polymorphic: Pr; _alloy: Pr 1_ | model | [1] Norgren 2000; _cites Huasen 1995_ | Table 1, p. 4, row 5; `ORC-ZKSNHDO4EN` | | ### Crystal structure (7) Table: Crystal structure, Pr system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Lattice a | 4.13 Å | | (β Pr); _alloy: Pr 1_ | experimental | [2] Peng 2011; _cites Spedding 1961_ [doi](https://doi.org/10.1016/0022-5088%2861%2990003-0) | Table 1, p. 2, row 13; `ORC-23BXM67U66` | | | Lattice a | 3.67 Å | 298.15 | (α Pr); _alloy: Pr 1_ | experimental | [2] Peng 2011; _cites Smirnov 1974_ | Table 1, p. 2, row 12; `ORC-FS7MOC24IL.95714a` | | | Lattice a | 3.6721 Å | 298.15 | αPr; _αPr: Pr 1_ | unspecified | [3] Wang 2015; _cites ref. 1965Jos_ | Table 1, p. 2, row 8; `ORC-2AXYGHCQXN.e4aea4` | | | Lattice a | 4.13 Å | 298.15 | βPr; _alloy: Pr 1_ | unspecified | [3] Wang 2015; _cites ref. 1993Sac_ | Table 1, p. 2, row 7; `ORC-NX57FOIEHI` | | | Lattice a | 4.13 Å | 298.15 | βPra; _βPra: Pr 1_ | unspecified | [3] Wang 2015; _cites ref. 1993Sac_ | Table 1, p. 2, row 15; `ORC-HBQCN63HJU` | | | Lattice b | 11.8326 Å | 298.15 | αPr; _αPr: Pr 1_ | unspecified | [3] Wang 2015; _cites ref. 1965Jos_ | Table 1, p. 2, row 8; `ORC-2AXYGHCQXN.9edbc3` | | | Lattice c | 11.83 Å | 298.15 | (α Pr); _alloy: Pr 1_ | experimental | [2] Peng 2011; _cites Smirnov 1974_ | Table 1, p. 2, row 12; `ORC-FS7MOC24IL.e4f35f` | | ## Sources Reporting papers the values were read from (a value cited from another work names that work in its row). 1. Susanne Norgren, Thermodynamic assessment of the Ho-Tb, Ho-Dy, Ho-Er, Er-Tb, and Er-Dy systems, JPE 21, 148-156 (2000). [doi:10.1361/105497100770340200](https://doi.org/10.1361/105497100770340200) 2. Yingbiao Peng, Yong Du, Lijun Zhang, Chunsheng Sha, Shuhong Liu, Feng Zheng et al., Thermodynamic modeling of the C–RE (RE=La, Ce and Pr) systems, Calphad 35, 533-541 (2011). [doi:10.1016/j.calphad.2011.09.002](https://doi.org/10.1016/j.calphad.2011.09.002) 3. Peisheng Wang, Rainer Schmid-Fetzer, Thermodynamic assessment of the Mg–Pr system, Computational Materials Science 104, 138-142 (2015). [doi:10.1016/j.commatsci.2014.11.050](https://doi.org/10.1016/j.commatsci.2014.11.050) ## Please cite - R. Arróyave, J. Saal, D. Shin, ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23735569 - 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 the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work); 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). 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_literature_2026, author = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon}, title = {{ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature}}, version = {2026.10}, publisher = {Zenodo}, year = {2026}, doi = {10.5281/zenodo.23735569}, url = {https://doi.org/10.5281/zenodo.23735569}, 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 ORCHID ([CITATION.cff](https://data.orchid-project.org/CITATION.cff)) and the original sources. Quotes are short excerpts kept so that each value can be checked; they remain under the publishers' copyright and are not relicensed. Source papers, page images and full text are not redistributed. Field reference: [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt). Found an error? The report link of a value (Markdown: its id, ORC-..., in the Location column) opens a pre-filled GitHub issue, https://github.com/orchid-calphad/orchid-data/issues/new?template=report-value-error.yml&record_id=\, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).