# GeS2: enthalpy of formation

> Enthalpy of formation of GeS2: 9 literature value(s) with sources, pages and quotes and DFT values (Materials Project / OQMD), from ORCHID.

HTML: https://data.orchid-project.org/compounds/GeS2.html · Markdown: https://data.orchid-project.org/compounds/GeS2.md

9 accepted literature formation-enthalpy value(s) (experimental 4, model 4, unspecified 1); experimental median -46.3 kJ/mol-atom (n = 4); Materials Project -64.065 kJ/mol-atom (mp-aaabgpmi); OQMD -50.116 kJ/mol-atom (oqmd-2017).

Systems: [Ge–S](https://data.orchid-project.org/systems/GE-S.html)

## Literature values

Table: Enthalpy of formation of GeS2 reported in the literature (9)

| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---:|---|---:|---|---|---|---|---|---|
| -52.3 kJ/mol-atom ± 4.3 | GeS2 | 298.15 | experimental | Fluorine bomb calorimetry | [Ge–S](https://data.orchid-project.org/systems/GE-S.html) | [1] Chen 2022; _cites ref. 60_ | Table II, p. 3, row 42; `ORC-4TF6HMXWH2.3852a2` |  |
| -50 kJ/mol-atom ± 6.7 | GeS2 | 298.15 | experimental | Third law | [Ge–S](https://data.orchid-project.org/systems/GE-S.html) | [1] Chen 2022; _cites ref. 64_ | Table II, p. 3, row 43; `ORC-U6SKC776SP.f248ff` |  |
| -42.6 kJ/mol-atom ± 0.4 | GeS2 | 298.15 | experimental | Calorimetry | [Ge–S](https://data.orchid-project.org/systems/GE-S.html) | [1] Chen 2022; _cites ref. 66_ | Table II, p. 3, row 39; `ORC-FQ6A25FGYJ.232cbd` |  |
| -41.6 kJ/mol-atom ± 0.9 | GeS2 | 298.15 | experimental | Fluorine bomb calorimetry | [Ge–S](https://data.orchid-project.org/systems/GE-S.html) | [1] Chen 2022; _cites ref. 65_ | Table II, p. 3, row 40; `ORC-SGPWYVDIGH.92a463` |  |
| -69.55 kJ/mol-atom | GeS2 | 0 | model | First–principles | [Ge–S](https://data.orchid-project.org/systems/GE-S.html) | [1] Chen 2022; _cites ref. 36_ | Table II, p. 3, row 45; `ORC-37ZYCFUMUL.a312d4` |  |
| -50.03 kJ/mol-atom | GeS2 | 0 | model | First–principles | [Ge–S](https://data.orchid-project.org/systems/GE-S.html) | [1] Chen 2022; _cites Saal 2013_ | Table II, p. 3, row 44; `ORC-M7S7BYQTFF.7d7343` |  |
| -48.733 kJ/mol-atom | GeS2 | 298.15 | model | CALPHAD | [Ge–S](https://data.orchid-project.org/systems/GE-S.html) | [1] Chen 2022 | Table II, p. 3, row 47; `ORC-TXLKM4EHRC.8d4e0d` |  |
| -45.91 kJ/mol-atom | GeS2 | 298.15 | model | Statistical mechanical | [Ge–S](https://data.orchid-project.org/systems/GE-S.html) | [1] Chen 2022; _cites ref. 63_ | Table II, p. 3, row 41; `ORC-L4Z2KBX534.30941a` |  |
| -31.88 kJ/mol-atom | GeS2 | 0 | unspecified | First–principles | [Ge–S](https://data.orchid-project.org/systems/GE-S.html) | [1] Chen 2022 | Table II, p. 3, row 46; `ORC-2O5LFMT42I.b500e1` |  |

### Uncertainty budget

Components kept separate, in the value's unit (literature [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md), [UNCERTAINTY_CALIBRATION.md](https://data.orchid-project.org/literature/UNCERTAINTY_CALIBRATION.md)): effective = max(sqrt(max(printed, reading, method)^2 + composition^2 + conversion^2), scatter). The method floor is the robust between-study scatter of the method class in ORCHID (calibrated) or a documented prior; printed values and printed uncertainties are unchanged.

Table: Uncertainty budget of the literature values of GeS2

| Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective |
|---:|---|---:|---:|---|---:|---:|---:|---:|
| -52.3 | kJ/mol-atom | 4.3 | 0.05 | 1 (combustion_calorimetry, cleaned_below_threshold) |  |  |  | 4.3 |
| -50 | kJ/mol-atom | 6.7 | 0.5 | 2 (kems_vapour_third_law, prior) |  |  |  | 6.7 |
| -42.6 | kJ/mol-atom | 0.4 | 0.05 | 3.2 (solution_reaction_calorimetry, calibrated) |  |  |  | 3.2 |
| -41.6 | kJ/mol-atom | 0.9 | 0.05 | 1 (combustion_calorimetry, cleaned_below_threshold) |  |  |  | 1 |
| -69.55 | kJ/mol-atom |  | 0.005 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -50.03 | kJ/mol-atom |  | 0.005 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -48.733 | kJ/mol-atom |  | 5.000e-4 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -45.91 | kJ/mol-atom |  | 0.005 | 3.9 (model_calculated, calibrated) |  |  |  | 3.9 |
| -31.88 | kJ/mol-atom |  | 0.005 | 4.1 (experimental_unspecified, cleaned_below_threshold) |  |  |  | 4.1 |

## DFT formation energies

Lowest-energy entries at this composition. Materials Project and OQMD use different energy references and are never averaged. 1 eV/atom = 96.485 kJ/mol-atom.

Table: DFT formation energy of GeS2

| Source | Entry | kJ/mol-atom | eV/atom | Space group | E above hull (kJ/mol-atom) | E above hull (eV/atom) | Theoretical |
|---|---|---:|---:|---|---:|---:|---|
| Materials Project | mp-aaabgpmi | -64.065 | -0.663994 | P2_1/c | 0 | 0 | no |
| OQMD | oqmd-2017 | -50.116 | -0.519418 | P21/c | 0 | 0 | no |

DFT sources: A. Jain et al., Commentary: The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002. [doi:10.1063/1.4812323](https://doi.org/10.1063/1.4812323) (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501-1509; S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010. [doi:10.1007/s11837-013-0755-4](https://doi.org/10.1007/s11837-013-0755-4) (CC BY 4.0); 

## Sources

1. 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)

## 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-Parity: DFT-vs-experiment formation-enthalpy benchmark (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23735943
- 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); 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); G. Kim, S. V. Meschel, P. Nash, W. Chen, Experimental formation enthalpies for intermetallic phases and other inorganic compounds, Scientific Data 4 (2017) 170162, https://doi.org/10.1038/sdata.2017.162; 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.

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_dft_benchmark_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Parity: DFT-vs-experiment formation-enthalpy benchmark}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735943},
  url       = {https://doi.org/10.5281/zenodo.23735943},
  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/).