# Ba–Ca system

> Ba–Ca system: 10 accepted literature values (mixing / partial 9, crystal structure 1) and 1 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

HTML: https://data.orchid-project.org/systems/BA-CA.html · Markdown: https://data.orchid-project.org/systems/BA-CA.md

10 accepted literature values from 1 paper(s) (experimental 9, unspecified 1); 1 calculated phase diagram(s). 3 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV.

Data: [JSON](https://data.orchid-project.org/literature/systems/BA-CA.json) · [CSV](https://data.orchid-project.org/systems/BA-CA.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#BA-CA) · [interactive phase diagram](https://orchid-project.org/phase-diagrams/#BA-CA/BaCa-86Alc.json) · [phases (4)](https://data.orchid-project.org/phases/pages/BA-CA.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/BA-CA.html) · [Markdown](https://data.orchid-project.org/systems/BA-CA.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 9 |
| unspecified | 1 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| mixing / partial | 9 |
| crystal structure | 1 |

## Calculated phase diagrams

Binary phase diagrams calculated with pycalphad 0.11.2 from the SGTE binary collection (Hallstedt 2025, CC BY 4.0). Evidence class: model.

Table: Assessments with a calculated phase diagram

| TDB file | Assessment | SHA-256 | Links |
|---|---|---|---|
| BaCa-86Alc.tdb | C.B. Alcock, V.P. Itkin, Bull. Alloy Phase Diag., 7, 338-40(1986). [doi:10.1007/BF02873004](https://doi.org/10.1007/BF02873004) | `de9409bef87b35fa57d2add00c37a0dd78df70066a76149e1d69edeeb4d558b1` | [viewer](https://orchid-project.org/phase-diagrams/#BA-CA/BaCa-86Alc.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/BaCa-86Alc.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/BaCa-86Alc.json) |

Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/BA/BA-CA.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/BA/BA-CA.json)

## Other properties

### Mixing / partial (9)

Table: Mixing / partial, Ba–Ca system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Enthalpy of mixing; _printed: Δmix H_ | -1.234 kJ/mol (basis unstated) |  | liquid; _alloy: Ba 0.2, Ca 0.8_ | experimental | [1] Alcock 1986; _cites ref. 74Pre_ | Table 2, p. 3, row 1; `ORC-5P2HZR5AFA` |  |
| Enthalpy of mixing; _printed: Δmix H_ | -2.301 kJ/mol (basis unstated) |  | liquid; _alloy: Ba 0.48, Ca 0.52_ | experimental | [1] Alcock 1986; _cites ref. 74Pre_ | Table 2, p. 3, row 5; `ORC-6DHPJSDAQH` |  |
| Enthalpy of mixing; _printed: Δmix H_ | -1.611 kJ/mol (basis unstated) |  | liquid; _alloy: Ba 0.805, Ca 0.195_ | experimental | [1] Alcock 1986; _cites ref. 74Pre_ | Table 2, p. 3, row 9; `ORC-EPMZMCGT3C` |  |
| Enthalpy of mixing; _printed: Δmix H_ | -2.134 kJ/mol (basis unstated) |  | liquid; _alloy: Ba 0.63, Ca 0.37_ | experimental | [1] Alcock 1986; _cites ref. 74Pre_ | Table 2, p. 3, row 7; `ORC-FUSEK67UD2` |  |
| Enthalpy of mixing; _printed: Δmix H_ | -2.28 kJ/mol (basis unstated) |  | liquid; _alloy: Ba 0.55, Ca 0.45_ | experimental | [1] Alcock 1986; _cites ref. 74Pre_ | Table 2, p. 3, row 6; `ORC-HXKSKMOEB4` |  |
| Enthalpy of mixing; _printed: Δmix H_ | -1.904 kJ/mol (basis unstated) |  | liquid; _alloy: Ba 0.27, Ca 0.73_ | experimental | [1] Alcock 1986; _cites ref. 74Pre_ | Table 2, p. 3, row 2; `ORC-LGZ2AIFHDL` |  |
| Enthalpy of mixing; _printed: Δmix H_ | -1.925 kJ/mol (basis unstated) |  | liquid; _alloy: Ba 0.71, Ca 0.29_ | experimental | [1] Alcock 1986; _cites ref. 74Pre_ | Table 2, p. 3, row 8; `ORC-NCBAL4STC4` |  |
| Enthalpy of mixing; _printed: Δmix H_ | -2.008 kJ/mol (basis unstated) |  | liquid; _alloy: Ba 0.34, Ca 0.66_ | experimental | [1] Alcock 1986; _cites ref. 74Pre_ | Table 2, p. 3, row 3; `ORC-OQM4PDTFOE` |  |
| Enthalpy of mixing; _printed: Δmix H_ | -2.284 kJ/mol (basis unstated) |  | liquid; _alloy: Ba 0.44, Ca 0.56_ | experimental | [1] Alcock 1986; _cites ref. 74Pre_ | Table 2, p. 3, row 4; `ORC-PHQB3F3NBQ` |  |

### Crystal structure (1)

Table: Crystal structure, Ba–Ca system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 0.581 not_printed | 473.15 | (αCa); _(αCa): Ba 0.3, Ca 0.7_ | unspecified | [1] Alcock 1986; _cites ref. 49She_ | Table 1, p. 2, row 2; `ORC-OAHHFB6UKB` |  |

## Sources

Reporting papers the values were read from (a value cited from another work names that work in its row).

1. C. B. Alcock, V. P. Itkin, The Ba−Ca (Barium-Calcium) system, Bulletin of Alloy Phase Diagrams 7, 338-340 (1986). [doi:10.1007/bf02873004](https://doi.org/10.1007/bf02873004)

## 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-Diagrams: calculated binary phase diagrams (version 2026.10), Zenodo (2026). https://doi.org/10.5281/zenodo.23735859
- R. Arróyave, J. Saal, D. Shin, ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD) (version 2026.10), Zenodo (2026). https://doi.org/10.5281/zenodo.23735891
- 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_phase_diagrams_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Diagrams: calculated binary phase diagrams}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735859},
  url       = {https://doi.org/10.5281/zenodo.23735859}
}

@misc{orchid_hulls_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD)}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735891},
  url       = {https://doi.org/10.5281/zenodo.23735891}
}

@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=\<id>, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).