# Ga–N system > Ga–N system: 23 accepted literature values (heat capacity / entropy / enthalpy 11, formation 8, phase transition 4) and 2 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote. HTML: https://data.orchid-project.org/systems/GA-N.html · Markdown: https://data.orchid-project.org/systems/GA-N.md 23 accepted literature values from 2 paper(s) (experimental 4, model 2, unspecified 17); 2 calculated phase diagram(s). 4 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/GA-N.json) · [CSV](https://data.orchid-project.org/systems/GA-N.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#GA-N) · [interactive phase diagram](https://orchid-project.org/phase-diagrams/#GA-N/GaN-03Unl.json) · [phases (5)](https://data.orchid-project.org/phases/pages/GA-N.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/GA-N.html) · [Markdown](https://data.orchid-project.org/systems/GA-N.md) Table: Accepted values by evidence class | Evidence class | Values | |---|---:| | experimental | 4 | | model | 2 | | unspecified | 17 | Table: Accepted values by property group | Property group | Values | |---|---:| | phase transition | 4 | | formation | 8 | | heat capacity / entropy / enthalpy | 11 | ## 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 | |---|---|---|---| | GaN-03Unl.tdb | J. Unland, B. Onderka, A. Davydov, R. Schmid-Fetzer, J. Cryst. Growth, 256, 33-51(2003). [doi:10.1016/S0022-0248(03)01352-6](https://doi.org/10.1016/S0022-0248%2803%2901352-6) | `eb023f7ceb4ad845c783c44fc3241e37e257661ace881cd9ac75f7bf8666187a` | [viewer](https://orchid-project.org/phase-diagrams/#GA-N/GaN-03Unl.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/GaN-03Unl.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/GaN-03Unl.json) | | GaN-98Dav.tdb | A.V. Davydov, T.J. Anderson, Electrochem. Soc. Proc. 98-18, 38-49(1998). | `879d60b9d25803c8732ebeef5da64d4598900a0604a8b9ffa51df68f2d52f070` | [viewer](https://orchid-project.org/phase-diagrams/#GA-N/GaN-98Dav.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/GaN-98Dav.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/GaN-98Dav.json) | Table: Calculated three-phase invariants (model, mole fraction of the second component) | TDB file | T (K) | Phases at the invariant | |---|---:|---| | GaN-03Unl.tdb | 1117.53 | LIQUID (x(N) 0) + GAN_B4 (x(N) 0.5) + GAS (x(N) 1) | | GaN-03Unl.tdb | 302.91 | LIQUID (x(N) 0) + ORTHORHOMBIC_A11 (x(N) 0) + GAN_B4 (x(N) 0.5) | | GaN-98Dav.tdb | 1052.57 | LIQUID (x(N) 0) + GAN_B4 (x(N) 0.5) + GAS (x(N) 1) | | GaN-98Dav.tdb | 302.91 | LIQUID (x(N) 0) + ORTHORHOMBIC_A11 (x(N) 0) + GAN_B4 (x(N) 0.5) | Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/GA/GA-N.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/GA/GA-N.json) · [CALPHAD hull GaN-98Dav](https://data.orchid-project.org/hulls/calphad-sgte/GA/GA-N--GaN-98Dav.json) ## 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, Ga–N system (8) | Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote | |---|---|---:|---:|---|---:|---:|---|---|---| | GaN | | -157.7 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Onderka 2002; _cites Madar 1975_ | Table AI, p. 18, row 25; `ORC-MK5TLO3SF5` | | | GaN | | -157.7 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Onderka 2002; _cites Karpinski 1984_ | Table AI, p. 18, row 26; `ORC-QQL76BGONT` | | | GaN | | -156.8 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Onderka 2002; _cites Ranade 2000_ | Table AI, p. 18, row 27; `ORC-PEOWFV2IWD` | | | GaN | | -140.2 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Onderka 2002; _cites MacChesney 1970_ | Table AI, p. 18, row 30; `ORC-LHYZF4HQHR` | | | GaN | | -140 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Onderka 2002; _cites Unland_ | Table AI, p. 18, row 17; `ORC-4T7BA2NHWJ.925d6c` | | | GaN | | -117.1 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Onderka 2002; _cites Davydov 1999_ | Table AI, p. 18, row 18; `ORC-XNAQL7HNT3.e3beeb` | | | GaN | | -104.2 kJ/mol (basis unstated) | 298.15 | unspecified | | | [1] Onderka 2002; _cites Hahn 1940_ | Table AI, p. 18, row 24; `ORC-LIAN2RVUAP` | | | GaN | [GaN](https://data.orchid-project.org/compounds/GaN.html) | -52.1 kJ/mol-atom ± 2 | 298.15 | experimental | -63.373 (mp-aaaaabey) | -55.891 (oqmd-6450) | [2] Unland 2003; _cites Hahn 1940_ [doi](https://doi.org/10.1002/zaac.19402440203) | Table 2, p. 3, row 1; `ORC-L4ZDFWE5GW` | | ## Other properties ### Phase transition (4) Table: Phase transition, Ga–N system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Phase transition | 1043 K | 1043 | other: GaN, Dynamic oscillation TGA, first heating cycle; _alloy: N 0.5_ | experimental | [2] Unland 2003 | Table 4, p. 5, row 1; `ORC-FK57YZZHWC` | | | Phase transition | 1085 K | 1085 | other: GaN, fast heating TGA (in ramp before 1275 K, 24 h); _alloy: N 0.5_ | experimental | [2] Unland 2003 | Table 4, p. 5, row 2; `ORC-QQ5EJWD4AD` | | | Phase transition | 1110 K | 1110 | other: GaN (+ in situ Ga) Isothermal stepping TGA, samples #1, #2, #3, assessed value; _alloy: N 0.5_ | experimental | [2] Unland 2003 | Table 4, p. 5, row 4; `ORC-QUBP5YRWM6` | | | Phase transition | 2700 K | 2700 | liquid | model | [2] Unland 2003 | p. 15; `ORC-JWKRDOKSBK` | “The experimental solubility data are compared to the calculated phase boundary based on Tm=2700 K in Fig. 8.” | ### Heat capacity / entropy / enthalpy (11) Table: Heat capacity / entropy / enthalpy, Ga–N system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Entropy; _printed: S°298_ | 26 J/mol-formula K | 298.15 | GaN | unspecified | [1] Onderka 2002; _cites Unland_ | Table AI, p. 18, row 17; `ORC-4T7BA2NHWJ.fd391f` | | | Entropy; _printed: S°298_ | 37 J/mol-formula K | 298.15 | GaN | unspecified | [1] Onderka 2002; _cites Davydov 1999_ | Table AI, p. 18, row 29; `ORC-E5BA3LD6XE` | | | Entropy; _printed: S°298_ | 36.5 J/mol-formula K | 298.15 | GaN | unspecified | [1] Onderka 2002; _cites Koshenko 1979_ | Table AI, p. 18, row 28; `ORC-FFB3FKS6MS` | | | Entropy; _printed: ΔmS_ | 67.4 J/mol-formula K | 298.15 | GaN | model | [1] Onderka 2002; _cites Jones 1984_ | Table AI, p. 18, row 19; `ORC-JMWXUEHMPP` | | | Entropy; _printed: ΔmS_ | 67.4 J/mol-formula K | 2700 | GaN | unspecified | [1] Onderka 2002; _cites Unland_ | Table AI, p. 18, row 17; `ORC-4T7BA2NHWJ.bd553d` | | | Entropy; _printed: ΔmS_ | 67 J/mol-formula K | 2791 | GaN | unspecified | [1] Onderka 2002; _cites Van 1973_ | Table AI, p. 18, row 15; `ORC-7S4ILD56YN` | | | Entropy; _printed: ΔmS_ | 31.5 J/mol-formula K | 2792 | GaN | unspecified | [1] Onderka 2002; _cites Davydov 1999_ | Table AI, p. 18, row 18; `ORC-XNAQL7HNT3.431058` | | | Heat capacity; _printed: Cp,298_ | 34.03 J/mol (basis unstated)/K | 298.15 | GaN | unspecified | [1] Onderka 2002; _cites Unland_ | Table AI, p. 18, row 17; `ORC-4T7BA2NHWJ.ff131c` | | | Heat capacity; _printed: Cp,298_ | 33.8 J/mol (basis unstated)/K | 298.15 | GaN | unspecified | [1] Onderka 2002; _cites Strelchenko 1984_ | Table AI, p. 18, row 23; `ORC-HIYYHVEOWV` | | | Heat capacity; _printed: Cp,298_ | 37.86 J/mol (basis unstated)/K | 298.15 | GaN | unspecified | [1] Onderka 2002; _cites Marina 1971_ | Table AI, p. 18, row 21; `ORC-PTDCOM6PXE` | | | Heat capacity; _printed: Cp,298_ | 35.19 J/mol (basis unstated)/K | 298.15 | GaN | unspecified | [1] Onderka 2002; _cites Demidenko 1975_ | Table AI, p. 18, row 22; `ORC-UIEMLZI5V4` | | ## Sources Reporting papers the values were read from (a value cited from another work names that work in its row). 1. B. Onderka, J. Unland, R. Schmid-Fetzer, Thermodynamics and phase stability in the In–N system, J. Mater. Res. 17, 3065-3083 (2002). [doi:10.1557/jmr.2002.0445](https://doi.org/10.1557/jmr.2002.0445) 2. J. Unland, B. Onderka, A. Davydov, R. Schmid-Fetzer, Thermodynamics and Phase Stability in the Ga–N System, Journal of Crystal Growth 256, 33-51 (2003). [doi:10.1016/s0022-0248(03)01352-6](https://doi.org/10.1016/s0022-0248%2803%2901352-6) ## 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=\, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).