# Ho system

> Ho system: 11 accepted literature values (crystal structure 7, formation 2, phase transition 2) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

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

11 accepted literature values from 5 paper(s) (experimental 4, model 2, DFT 4, unspecified 1); 0 calculated phase diagram(s). 1 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/HO.json) · [CSV](https://data.orchid-project.org/systems/HO.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#HO) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/HO.html) · [Markdown](https://data.orchid-project.org/systems/HO.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 4 |
| model | 2 |
| DFT | 4 |
| unspecified | 1 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| phase transition | 2 |
| formation | 2 |
| crystal structure | 7 |

## Formation enthalpies

Literature values in kJ/mol-atom where the per-atom basis is known. DFT columns: the lowest-energy entry at the same composition (Materials Project 2026.04.13, OQMD v1.8; different energy references, never averaged), from [dft_parity.json](https://data.orchid-project.org/literature/dft_parity.json).

Table: Enthalpies of formation, Ho system (2)

| Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote |
|---|---|---:|---:|---|---:|---:|---|---|---|
| Ho (fcc) |  | -1.18 kJ/mol-atom | 0 | DFT |  |  | [1] Dong 2012; _cites Wang 2004_ [doi](https://doi.org/10.1016/j.calphad.2004.05.002) | Table 1, p. 2, row 2; `ORC-M5IKCLOBJO.2f19a8` |  |
| Ho (fcc) |  | -1.18 kJ/mol-atom | 0 | DFT |  |  | [1] Dong 2012 | Table 1, p. 2, row 1; `ORC-WDC5NOCJMI.8f7064` |  |

## Other properties

### Phase transition (2)

Table: Phase transition, Ho system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Phase transition | 1703 K | 1703 | polymorphic: Ho; _alloy: Ho 1_ | model | [2] Norgren 2000; _cites Norgren_ | Table 1, p. 4, row 19; `ORC-BW6MXXMABF` |  |
| Phase transition | 1713.15 K | 1713.15 | polymorphic: (βHo) ↔ (αHo); _(βHo): Ho 1_ | unspecified | [3] Kardellass 2014; _cites Kubaschewski 1982_ | Table 1, p. 2, row 12; `ORC-UNBXALJLDN` |  |

### Crystal structure (7)

Table: Crystal structure, Ho system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 3.548 Å | 0 | (Ho); _(Ho): Ho 1_ | DFT | [4] Ghamri 2013 | Table 1, p. 2, row 2; `ORC-CD2SIKZRBS.311079` |  |
| Lattice a | 3.58 Å | 298.15 | (Ho); _(Ho): Ho 1_ | experimental | [4] Ghamri 2013; _cites Harris 1985_ [doi](https://doi.org/10.1016/0022-5088%2885%2990401-1) | Table 1, p. 2, row 1; `ORC-ZQKV7OKNBY.65ffad` |  |
| Lattice a; _printed: a_ | 4.967 Å | 298.15 | Ho (fcc); _alloy: Ho 1_ | model | [1] Dong 2012 | Table 1, p. 2, row 3; `ORC-3WYULLKRU5` |  |
| Lattice a | 3.58 Å | 298.15 | hcp(Ho); _alloy: Ho 1_ | experimental | [5] Cui 2023; _cites Spedding 1961_ [doi](https://doi.org/10.1016/0022-5088%2861%2990003-0) | Table 1, p. 2, row 5; `ORC-ULK4F5O6ZD.5e6c1c` |  |
| Lattice c | 5.82 Å | 0 | (Ho); _(Ho): Ho 1_ | DFT | [4] Ghamri 2013 | Table 1, p. 2, row 2; `ORC-CD2SIKZRBS.f2dd42` |  |
| Lattice c | 5.62 Å | 298.15 | (Ho); _(Ho): Ho 1_ | experimental | [4] Ghamri 2013; _cites Harris 1985_ [doi](https://doi.org/10.1016/0022-5088%2885%2990401-1) | Table 1, p. 2, row 1; `ORC-ZQKV7OKNBY.a014d3` |  |
| Lattice c | 5.62 Å | 298.15 | hcp(Ho); _alloy: Ho 1_ | experimental | [5] Cui 2023; _cites Spedding 1961_ [doi](https://doi.org/10.1016/0022-5088%2861%2990003-0) | Table 1, p. 2, row 5; `ORC-ULK4F5O6ZD.a88d20` |  |

## Sources

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

1. H.Q. Dong, X.M. Tao, T. Laurila, M. Paulasto-Kröckel, Thermodynamic assessment of Au–Ho and Au–Tm binary systems, Calphad 37, 87-93 (2012). [doi:10.1016/j.calphad.2012.02.002](https://doi.org/10.1016/j.calphad.2012.02.002)
2. 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)
3. S. Kardellass, C. Servant, N. Selhaoui, A. Iddaoudi, M. Ait Amar, L. Bouirden, A thermodynamic assessment of the Iron+Holmium phase diagram, The Journal of Chemical Thermodynamics 74, 78-84 (2014). [doi:10.1016/j.jct.2013.11.037](https://doi.org/10.1016/j.jct.2013.11.037)
4. H. Ghamri, A. Belgacem-Bouzida, Y. Djaballah, A. Hidoussi, Thermodynamic assessment of the Ho–Te system supported by ab initio calculations, Journal of Alloys and Compounds 552, 387-391 (2013). [doi:10.1016/j.jallcom.2012.11.084](https://doi.org/10.1016/j.jallcom.2012.11.084)
5. Dongyu Cui, Jiong Wang, Jiaqiang Zhou, Thermodynamic Modeling of the Te-X (X = Gd, Dy, Ho) Binary Systems Combined with the First-Principles Method, J. Phase Equilib. Diffus. 44, 456-467 (2023). [doi:10.1007/s11669-023-01051-1](https://doi.org/10.1007/s11669-023-01051-1)

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