# Se system

> Se system: 36 accepted literature values (crystal structure 23, other property 9, formation 4) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

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

36 accepted literature values from 6 paper(s) (experimental 14, DFT 20, unspecified 2); 0 calculated phase diagram(s).

Data: [JSON](https://data.orchid-project.org/literature/systems/SE.json) · [CSV](https://data.orchid-project.org/systems/SE.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#SE) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/SE.html) · [Markdown](https://data.orchid-project.org/systems/SE.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 14 |
| DFT | 20 |
| unspecified | 2 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| formation | 4 |
| crystal structure | 23 |
| other property | 9 |

## 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, Se system (4)

| Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote |
|---|---|---:|---:|---|---:|---:|---|---|---|
| α-Se |  | 21.468 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 6; `ORC-CZGXHBS3WD` |  |
| α-Se |  | 22.869 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 5; `ORC-BI46WSY6N6` |  |
| β-Se |  | 43.164 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 10; `ORC-HZD6GVO3YJ` |  |
| β-Se |  | 53.402 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 9; `ORC-3TBTKPQUR5` |  |

## Other properties

### Crystal structure (23)

Table: Crystal structure, Se system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 4.337 Å | 298.15 | (Se); _alloy: Se 1_ | experimental | [2] Chen 2022; _cites McCann 1972_ [doi](https://doi.org/10.1063/1.1660946) | Table I, p. 2, row 5; `ORC-S4XVYZUMAU.0525ee` |  |
| Lattice a | 0.43655 Å | 298.15 | (Se); _alloy: Se 1_ | unspecified | [3] Zhou 2024; _cites King 1981_ | Table 1, p. 2, row 2; `ORC-SA2QSGLLIH.749824` |  |
| Lattice a | 1.285 Å | 298.15 | (αSe); _alloy: Se 1_ | experimental | [4] Shi 2019; _cites Steigmann 1966_ [doi](https://doi.org/10.1107/s0365110x66001506) | Table 2, p. 3, row 6; `ORC-YEKOL6C7S4.c08632` |  |
| Lattice a | 0.905 Å | 298.15 | (βSe); _alloy: Se 1_ | experimental | [4] Shi 2019; _cites Howe 1989_ | Table 2, p. 3, row 7; `ORC-YLLOZCSYSY.ecef0a` |  |
| Lattice a | 4.3 Å | 298.15 | Hex(Se); _alloy: Se 1_ | experimental | [5] Liu 2023; _cites Massalski 1990_ | Table 1, p. 3, row 3; `ORC-M7G2KDQNAK.d340e7` |  |
| Lattice b | 4.337 Å | 298.15 | (Se); _alloy: Se 1_ | experimental | [2] Chen 2022; _cites McCann 1972_ [doi](https://doi.org/10.1063/1.1660946) | Table I, p. 2, row 5; `ORC-S4XVYZUMAU.886afa` |  |
| Lattice b | 0.807 Å | 298.15 | (αSe); _alloy: Se 1_ | experimental | [4] Shi 2019; _cites Steigmann 1966_ [doi](https://doi.org/10.1107/s0365110x66001506) | Table 2, p. 3, row 6; `ORC-YEKOL6C7S4.2d5940` |  |
| Lattice b | 0.907 Å | 298.15 | (βSe); _alloy: Se 1_ | experimental | [4] Shi 2019; _cites Howe 1989_ | Table 2, p. 3, row 7; `ORC-YLLOZCSYSY.0c6467` |  |
| Lattice c | 5.077 Å | 298.15 | (Se); _alloy: Se 1_ | experimental | [2] Chen 2022; _cites McCann 1972_ [doi](https://doi.org/10.1063/1.1660946) | Table I, p. 2, row 5; `ORC-S4XVYZUMAU.500ffa` |  |
| Lattice c | 0.49576 Å | 298.15 | (Se); _alloy: Se 1_ | unspecified | [3] Zhou 2024; _cites King 1981_ | Table 1, p. 2, row 2; `ORC-SA2QSGLLIH.f98650` |  |
| Lattice c | 0.931 Å | 298.15 | (αSe); _alloy: Se 1_ | experimental | [4] Shi 2019; _cites Steigmann 1966_ [doi](https://doi.org/10.1107/s0365110x66001506) | Table 2, p. 3, row 6; `ORC-YEKOL6C7S4.257605` |  |
| Lattice c | 1.161 Å | 298.15 | (βSe); _alloy: Se 1_ | experimental | [4] Shi 2019; _cites Howe 1989_ | Table 2, p. 3, row 7; `ORC-YLLOZCSYSY.d53f83` |  |
| Lattice c | 4.9537 Å | 298.15 | Hex(Se); _alloy: Se 1_ | experimental | [5] Liu 2023; _cites Massalski 1990_ | Table 1, p. 3, row 3; `ORC-M7G2KDQNAK.89f193` |  |
| volume; _printed: Volume_ | 28.19 Å3/atom | 0 | α-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 13; `ORC-2J3IJF7YJO.257b0d` |  |
| volume; _printed: Volume_ | 32.13 Å3/atom | 0 | α-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 12; `ORC-RDYP4KAE4D.b971b4` |  |
| volume; _printed: Volume_ | 31.49 Å3/atom | 0 | α′-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 20; `ORC-3643HULYWQ.b09946` |  |
| volume; _printed: Volume_ | 26.68 Å3/atom | 0 | α′-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 21; `ORC-LFYBM7T4H2.609e2f` |  |
| volume; _printed: Volume_ | 29.78 Å3/atom |  | α′-Se; _alloy: Se 1_ | experimental | [6] Guan 2017; _cites Gattow 1964_ [doi](https://doi.org/10.1002/zaac.19643310504) | Table 1, p. 5, row 19; `ORC-WMYFLDJS4K` |  |
| volume; _printed: Volume_ | 27.74 Å3/atom | 0 | β-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 15; `ORC-KNFD5X5M6B.543c0f` |  |
| volume; _printed: Volume_ | 32.52 Å3/atom | 0 | β-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 14; `ORC-RNUEKYIHKT.6b90a1` |  |
| volume; _printed: Volume_ | 23.08 Å3/atom | 0 | δ-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 18; `ORC-25Y5G5CDO6.7e9b6c` |  |
| volume; _printed: Volume_ | 25.99 Å3/atom | 0 | δ-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 17; `ORC-MNDDAGHKJK.fadd55` |  |
| volume; _printed: Volume_ | 26.57 Å3/atom |  | δ-Se; _alloy: Se 1_ | experimental | [6] Guan 2017; _cites Hamilton 1974_ [doi](https://doi.org/10.1016/s0022-3697%2874%2980126-5) | Table 1, p. 5, row 16; `ORC-VLZTITXMO3.a8eafe` |  |

### Other property (9)

Table: Other property, Se system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| bulk modulus; _printed: B0_ | 15.142 GPa | 0 | α-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 13; `ORC-2J3IJF7YJO.66716e` |  |
| bulk modulus; _printed: B0_ | 9.058 GPa | 0 | α-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 12; `ORC-RDYP4KAE4D.5d8149` |  |
| bulk modulus; _printed: B0_ | 7.737 GPa | 0 | α′-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 20; `ORC-3643HULYWQ.be3809` |  |
| bulk modulus; _printed: B0_ | 13.342 GPa | 0 | α′-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 21; `ORC-LFYBM7T4H2.b0f046` |  |
| bulk modulus; _printed: B0_ | 14.033 GPa | 0 | β-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 15; `ORC-KNFD5X5M6B.98b597` |  |
| bulk modulus; _printed: B0_ | 8.393 GPa | 0 | β-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 14; `ORC-RNUEKYIHKT.777876` |  |
| bulk modulus; _printed: B0_ | 34.163 GPa | 0 | δ-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 18; `ORC-25Y5G5CDO6.af81fd` |  |
| bulk modulus; _printed: B0_ | 14.359 GPa | 0 | δ-Se; _alloy: Se 1_ | DFT | [6] Guan 2017 | Table 1, p. 5, row 17; `ORC-MNDDAGHKJK.95c0b0` |  |
| bulk modulus; _printed: B0_ | 10.9925 GPa (range 7.085 to 14.9) |  | δ-Se; _alloy: Se 1_ | experimental | [6] Guan 2017; _cites Hamilton 1974_ [doi](https://doi.org/10.1016/s0022-3697%2874%2980126-5) | Table 1, p. 5, row 16; `ORC-VLZTITXMO3.9644a0` |  |

## Sources

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

1. Zhi Li, Shun-Li Shang, Jianyun Shen, Po-Hsien Liao, Zi-Kui Liu, Timothy J. Anderson, Thermodynamic Assessment of the Ag-Se System Aided by First-Principles Calculations, J. Phase Equilib. Diffus. 39, 870-881 (2018). [doi:10.1007/s11669-018-0683-7](https://doi.org/10.1007/s11669-018-0683-7)
2. Shanxiong Chen, Jiong Wang, Shangzhao Yu, Biao Hu, Qing Wu, Yong Du, Thermodynamic Modeling of the Ge-X (X = As, Se, S, P) Systems, J. Electron. Mater. 51, 2114-2130 (2022). [doi:10.1007/s11664-022-09474-1](https://doi.org/10.1007/s11664-022-09474-1)
3. Jiaqiang Zhou, Jiong Wang, Biao Hu, Dongyu Cui, Thermodynamic Modeling of the Bi-Se and Bi-Te Binary Systems, J. Phase Equilib. Diffus. 45, 89-113 (2024). [doi:10.1007/s11669-024-01093-z](https://doi.org/10.1007/s11669-024-01093-z)
4. Chenying Shi, Biaobiao Yang, Biao Hu, Yong Du, Sheng Yao, Thermodynamic Description of the Al–X (X = S, Se, Te) Systems, J. Phase Equilib. Diffus. 40, 392-402 (2019). [doi:10.1007/s11669-019-00733-z](https://doi.org/10.1007/s11669-019-00733-z)
5. Runlin Liu, Jiong Wang, Dongyu Cui, Thermodynamic Modeling of the Cu-Sb-Se System, J. Phase Equilib. Diffus. 44, 687-703 (2023). [doi:10.1007/s11669-023-01074-8](https://doi.org/10.1007/s11669-023-01074-8)
6. Pin-Wen Guan, Shun-Li Shang, Greta Lindwall, Tim Anderson, Zi-Kui Liu, First-principles calculations and thermodynamic modeling of the S-Se system and implications for chalcogenide alloys, Journal of Alloys and Compounds 694, 510-521 (2017). [doi:10.1016/j.jallcom.2016.10.037](https://doi.org/10.1016/j.jallcom.2016.10.037)

## 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/).