# Ag–Se system

> Ag–Se system: 95 accepted literature values (formation 56, heat capacity / entropy / enthalpy 16, phase transition 12, invariant reaction 10) and 3 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

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

95 accepted literature values from 2 paper(s) (experimental 54, model 15, DFT 24, unspecified 2); 3 calculated phase diagram(s). 10 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/AG-SE.json) · [CSV](https://data.orchid-project.org/systems/AG-SE.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#AG-SE) · [interactive phase diagram](https://orchid-project.org/phase-diagrams/#AG-SE/AgSe-18Li.json) · [phases (9)](https://data.orchid-project.org/phases/pages/AG-SE.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/AG-SE.html) · [Markdown](https://data.orchid-project.org/systems/AG-SE.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 54 |
| model | 15 |
| DFT | 24 |
| unspecified | 2 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| invariant reaction | 10 |
| phase transition | 12 |
| formation | 56 |
| heat capacity / entropy / enthalpy | 16 |
| other property | 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 |
|---|---|---|---|
| AgSe-18Li.tdb | Z. Li, S.-L. Shang, J. Shen, P.-H. Liao, Z.-K. Liu, T.J. Anderson, J. Phase Equilib. Diffus., 39, 870-81(2018). [doi:10.1007/s11669-018-0683-7](https://doi.org/10.1007/s11669-018-0683-7) | `5c67cbc09a8493422619e5b430fd6e6113c2a0a1f73714fb5425b52b51531de6` | [viewer](https://orchid-project.org/phase-diagrams/#AG-SE/AgSe-18Li.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/AgSe-18Li.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/AgSe-18Li.json) |
| AgSe-18Raj.tdb | V.B. Rajkumar, S.-W. Chen, Calphad, 63, 51-60(2018). [doi:10.1016/j.calphad.2018.08.004](https://doi.org/10.1016/j.calphad.2018.08.004) | `006f78e8a914d0c0089987deea3b481ab30b7db0e106de8feec91d051a4df59d` | [viewer](https://orchid-project.org/phase-diagrams/#AG-SE/AgSe-18Raj.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/AgSe-18Raj.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/AgSe-18Raj.json) |
| AgSe-24Hut.tdb | Y. Hutabalian, S.-W. Chen, W. Gierlotka, Calphad, 86, 102709(2024). [doi:10.1016/j.calphad.2024.102709](https://doi.org/10.1016/j.calphad.2024.102709) | `0dbcbc54a481f33f417d41953fff00320dceed440bbe8fa9d93788fad2db6c59` | [viewer](https://orchid-project.org/phase-diagrams/#AG-SE/AgSe-24Hut.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/AgSe-24Hut.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/AgSe-24Hut.json) |

Table: Calculated three-phase invariants (model, mole fraction of the second component)

| TDB file | T (K) | Phases at the invariant |
|---|---:|---|
| AgSe-18Li.tdb | 1742.4 | ION#2 (x(Se) 0.15254) + ION (x(Se) 0.32511) + GAS (x(Se) 0.99732) |
| AgSe-18Li.tdb | 1162.23 | FCC_A1 (x(Se) 0) + ION#2 (x(Se) 0.07694) + ION (x(Se) 0.3071) |
| AgSe-18Li.tdb | 1113.29 | FCC_A1 (x(Se) 0) + ION (x(Se) 0.30875) + AG2SE_BETA (x(Se) 0.33313) |
| AgSe-18Li.tdb | 1008.98 | ION#2 (x(Se) 0.41546) + ION (x(Se) 0.92063) + GAS (x(Se) 1) |
| AgSe-18Li.tdb | 887.49 | AG2SE_BETA (x(Se) 0.33332) + ION (x(Se) 0.43894) + ION#2 (x(Se) 0.93915) |
| AgSe-18Li.tdb | 490.09 | AG2SE_BETA (x(Se) 0.33333) + ION (x(Se) 0.97149) + HEXAGONAL_A8 (x(Se) 1) |
| AgSe-18Li.tdb | 405.44 | AG2SE_BETA (x(Se) 0.33333) + AG2SE_ALPHA (x(Se) 0.33335) + HEXAGONAL_A8 (x(Se) 1) |
| AgSe-18Li.tdb | 404.86 | FCC_A1 (x(Se) 0) + AG2SE_BETA (x(Se) 0.33292) + AG2SE_ALPHA (x(Se) 0.33319) |
| AgSe-18Raj.tdb | 2406.69 | LIQUID#2 (x(Se) 0.06911) + GAS (x(Se) 0.28259) + LIQUID (x(Se) 0.28533) |
| AgSe-18Raj.tdb | 1163.78 | FCC_A1 (x(Se) 0) + LIQUID#2 (x(Se) 0.05734) + LIQUID (x(Se) 0.29765) |
| AgSe-18Raj.tdb | 1114.47 | FCC_A1 (x(Se) 0) + LIQUID (x(Se) 0.29988) + AG2SE_BETA (x(Se) 0.32521) |
| AgSe-18Raj.tdb | 1044.31 | LIQUID#2 (x(Se) 0.45116) + LIQUID (x(Se) 0.93881) + GAS (x(Se) 1) |
| AgSe-18Raj.tdb | 890.35 | AG2SE_BETA (x(Se) 0.33364) + LIQUID (x(Se) 0.4446) + LIQUID#2 (x(Se) 0.9482) |
| AgSe-18Raj.tdb | 476.73 | AG2SE_BETA (x(Se) 0.33334) + LIQUID (x(Se) 0.98321) + HEXAGONAL_A8 (x(Se) 1) |
| AgSe-18Raj.tdb | 405.23 | AG2SE_BETA (x(Se) 0.33333) + AG2SE_ALPHA (x(Se) 0.33333) + HEXAGONAL_A8 (x(Se) 1) |
| AgSe-18Raj.tdb | 405.22 | FCC_A1 (x(Se) 0) + AG2SE_BETA (x(Se) 0.33332) + AG2SE_ALPHA (x(Se) 0.33333) |
| AgSe-24Hut.tdb | 1163.58 | FCC_A1 (x(Se) 0) + LIQUID#2 (x(Se) 0.074) + LIQUID (x(Se) 0.31485) |
| AgSe-24Hut.tdb | 1134.7 | FCC_A1 (x(Se) 0) + LIQUID (x(Se) 0.31831) + AG2SE_BETA (x(Se) 0.33333) |
| AgSe-24Hut.tdb | 1006.51 | LIQUID (x(Se) 0.41461) + LIQUID#2 (x(Se) 0.92903) + GAS (x(Se) 1) |
| AgSe-24Hut.tdb | 891.38 | AG2SE_BETA (x(Se) 0.33333) + LIQUID (x(Se) 0.41901) + LIQUID#2 (x(Se) 0.95639) |
| AgSe-24Hut.tdb | 493.82 | AG2SE_BETA (x(Se) 0.33333) + LIQUID (x(Se) 0.99908) + HEXAGONAL_A8 (x(Se) 1) |
| AgSe-24Hut.tdb | 404.9 | AG2SE_BETA (x(Se) 0.33333) + AG2SE_ALPHA (x(Se) 0.33333) + HEXAGONAL_A8 (x(Se) 1) |
| AgSe-24Hut.tdb | 404.9 | FCC_A1 (x(Se) 0) + AG2SE_ALPHA (x(Se) 0.33333) + AG2SE_BETA (x(Se) 0.33333) |

Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/AG/AG-SE.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/AG/AG-SE.json) · [CALPHAD hull AgSe-18Li](https://data.orchid-project.org/hulls/calphad-sgte/AG/AG-SE--AgSe-18Li.json) · [CALPHAD hull AgSe-18Raj](https://data.orchid-project.org/hulls/calphad-sgte/AG/AG-SE--AgSe-18Raj.json)

## Invariant reactions (literature)

Table: Invariant reactions reported in the literature for the Ag–Se system (10)

| T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote |
|---:|---|---|---|---|---|---|
| 1163.01 | monotectic: L1 -> Ag + L2 | L1: Se 0.076; Ag: Se 0; L2: Se 0.307 | model | [1] Li 2018 | Table 6, p. 9, row 4; `ORC-2N35PGMSJA` |  |
| 1163 | monotectic: L1 -> Ag + L2 | L1: Se 0.082; Ag: Se 0; L2: Se 0.312 | experimental | [1] Li 2018; _cites Wiggett 1999_ [doi](https://doi.org/10.1007/s11663-999-0019-4) | Table 6, p. 9, row 2; `ORC-35IHIHH2MO` |  |
| 1163 | monotectic: L1 -> Ag + L2 | L1: Se 0.12; Ag: Se 0; L2: Se 0.313 | experimental | [1] Li 2018; _cites Pellini 1915_ | Table 6, p. 9, row 1; `ORC-J75BIA26YR` |  |
| 1163 | monotectic: L1 -> Ag + L2 | L1: Se 0.11; Ag: Se 0; L2: Se 0.31 | experimental | [1] Li 2018; _cites Houphouet-Boigny 1984_ [doi](https://doi.org/10.1016/0022-5088%2884%2990272-8) | Table 6, p. 9, row 3; `ORC-Q23442VCCM` |  |
| 1113 | eutectic: L2 -> Ag + β-Ag2Se | L2: Se 0.32; Ag: Se 0; β-Ag2Se: Se 0.333 | experimental | [1] Li 2018; _cites Friedrich 1908_ | Table 6, p. 9, row 5; `ORC-FAPEESMBQB` |  |
| 1112.53 | eutectic: L2 -> Ag + β-Ag2Se | L2: Se 0.30876; Ag: Se 0; β-Ag2Se: Se 0.333 | model | [1] Li 2018 | Table 6, p. 9, row 6; `ORC-VP2FQGO6RM` |  |
| 889 | monotectic: L2 -> β-Ag2Se + L3 | L2: Se 0.445; β-Ag2Se: Se 0.333; L3: Se 0.955 | unspecified | [1] Li 2018; _cites Pelabon 1906_ | Table 6, p. 9, row 11; `ORC-GQQB5KQV7F` |  |
| 887.31 | monotectic: L2 -> β-Ag2Se + L3 | L2: Se 0.439; β-Ag2Se: Se 0.333; L3: Se 0.9402 | model | [1] Li 2018 | Table 6, p. 9, row 12; `ORC-WSFH6IWL6I` |  |
| 490 | eutectic: L3 -> β-Ag2Se + Se | L3: Se 1; β-Ag2Se: Se 0.333; Se: Se 1 | unspecified | [1] Li 2018; _cites Karakaya 1990_ [doi](https://doi.org/10.1007/bf03029297) | Table 6, p. 9, row 13; `ORC-YOZQ6UHO5I` |  |
| 489.75 | eutectic: L3 -> β-Ag2Se + Se | L3: Se 0.9714; β-Ag2Se: Se 0.333; Se: Se 1 | model | [1] Li 2018 | Table 6, p. 9, row 14; `ORC-WGYJUDV544` |  |

## 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, Ag–Se system (40)

| Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote |
|---|---|---:|---:|---|---:|---:|---|---|---|
| α-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -14.3633 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Voronin 2011_ [doi](https://doi.org/10.1134/s1023193511040203) | Table 1, p. 3, row 4; `ORC-IAHORPYKKP.ee26d1` |  |
| α-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -14.2433 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Osadchii 2007_ [doi](https://doi.org/10.2138/am.2007.2209) | Table 1, p. 3, row 1; `ORC-DENBWB3K3C.f053d3` |  |
| α-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -14.2433 kJ/mol-atom | 298.15 | model | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018 | Table 1, p. 3, row 9; `ORC-EG4CZFRGL7.4223e1` |  |
| α-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -14.2333 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Nasar 1997_ [doi](https://doi.org/10.1007/s11663-997-0120-5) | Table 1, p. 3, row 2; `ORC-NOQDCUENTV.b287ad` |  |
| α-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -14.1367 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Voronin 2011_ [doi](https://doi.org/10.1134/s1023193511040203) | Table 1, p. 3, row 3; `ORC-IYYBFJIDJR.5ed8ac` |  |
| α-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -14.12 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Grnvold 2003_ [doi](https://doi.org/10.1016/s0040-6031%2802%2900470-7) | Table 1, p. 3, row 7; `ORC-S7IJ2WTKZG.8ae02e` |  |
| α-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -13.7067 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Feng 2013_ [doi](https://doi.org/10.1016/j.ssi.2012.10.013) | Table 1, p. 3, row 8; `ORC-3HNT2KROYM.68a880` |  |
| α-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -13.54 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Oehsen 1981_ [doi](https://doi.org/10.1002/bbpc.19810850104) | Table 1, p. 3, row 5; `ORC-N7ZOMZ7UNS.c3fba0` |  |
| α-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -13.3667 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Olin 2005_ | Table 1, p. 3, row 6; `ORC-RMJA7ZD7GC.11b1bd` |  |
| α-Ag2Se |  | -9.936 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 1; `ORC-BC2LZ73AND.5a2061` |  |
| α-Ag2Se |  | -5.869 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 2; `ORC-UZUVCSCTEU.6ee1ba` |  |
| α-Ag₂Se |  | -9.936 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 1; `ORC-BC2LZ73AND.e8e3fd` |  |
| α-Ag₂Se |  | -5.869 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 2; `ORC-UZUVCSCTEU.c30a3c` |  |
| β-Ag12Se2 |  | 91.738 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 13; `ORC-O3K7RVVLMH.3f510e` |  |
| β-Ag12Se2 |  | 97.68 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 14; `ORC-SO4KQ2RZF6.a6b555` |  |
| β-Ag18Se2 |  | 149.37 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 18; `ORC-BMYIGKRGHQ.ab4c43` |  |
| β-Ag18Se2 |  | 150.532 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 17; `ORC-BR3BJ3WAT2.987c33` |  |
| β-Ag24Se2 |  | 20.119 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 15; `ORC-C6A7BK3CRU.8be91d` |  |
| β-Ag24Se2 |  | 20.653 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 16; `ORC-2IEPTMKRTC.7da0d9` |  |
| β-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -14.2333 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Nasar 1997_ [doi](https://doi.org/10.1007/s11663-997-0120-5) | Table 1, p. 3, row 15; `ORC-FORFJG353E.50f713` |  |
| β-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -11.6867 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Feng 2013_ [doi](https://doi.org/10.1016/j.ssi.2012.10.013) | Table 1, p. 3, row 13; `ORC-JFXIVMRCAO.aecbc9` |  |
| β-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -11.6833 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Grnvold 2003_ [doi](https://doi.org/10.1016/s0040-6031%2802%2900470-7) | Table 1, p. 3, row 12; `ORC-IR25DWRF5G.7f35b1` |  |
| β-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -11.68 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Voronin 2011_ [doi](https://doi.org/10.1134/s1023193511040203) | Table 1, p. 3, row 11; `ORC-FCNMFTUR4E.f22bb3` |  |
| β-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -11.6733 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Osadchii 2007_ [doi](https://doi.org/10.2138/am.2007.2209) | Table 1, p. 3, row 10; `ORC-DYLEZCG4HM.87c197` |  |
| β-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -11.67 kJ/mol-atom | 298.15 | model | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018 | Table 1, p. 3, row 16; `ORC-G2E5AOIVAY.1d15e8` |  |
| β-Ag2Se | [Ag2Se](https://data.orchid-project.org/compounds/Ag2Se.html) | -11.6667 kJ/mol-atom | 298.15 | experimental | -21.663 (mp-aaabgjqe) | -7.938 (oqmd-1374449) | [1] Li 2018; _cites Oehsen 1981_ [doi](https://doi.org/10.1002/bbpc.19810850104) | Table 1, p. 3, row 14; `ORC-PJHC2KGG2M.da54bd` |  |
| β-Ag2Se |  | -4.127 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 7; `ORC-QDB2TFAHB5.03d7af` |  |
| β-Ag2Se |  | -3.196 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 8; `ORC-5Y5PRUZMB2.3ca8e9` |  |
| β-Ag6Se2 |  | 13.937 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 11; `ORC-FTPU3E5TTQ.038558` |  |
| β-Ag6Se2 |  | 22.092 kJ/mol-atom |  | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 12; `ORC-F6WUAXESL4.a1a014` |  |
| β-Ag₁₂Se₂ |  | 91.738 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 13; `ORC-O3K7RVVLMH.208d9a` |  |
| β-Ag₁₂Se₂ |  | 97.68 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 14; `ORC-SO4KQ2RZF6.e28110` |  |
| β-Ag₁₈Se₂ |  | 149.37 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 18; `ORC-BMYIGKRGHQ.ae82ec` |  |
| β-Ag₁₈Se₂ |  | 150.532 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 17; `ORC-BR3BJ3WAT2.012e0d` |  |
| β-Ag₂Se |  | -4.127 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 7; `ORC-QDB2TFAHB5.10dd99` |  |
| β-Ag₂Se |  | -3.196 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 8; `ORC-5Y5PRUZMB2.c05b32` |  |
| β-Ag₂₄Se₂ |  | 20.119 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 15; `ORC-C6A7BK3CRU.d000ab` |  |
| β-Ag₂₄Se₂ |  | 20.653 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 16; `ORC-2IEPTMKRTC.d17026` |  |
| β-Ag₆Se₂ |  | 13.937 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 11; `ORC-FTPU3E5TTQ.3cc763` |  |
| β-Ag₆Se₂ |  | 22.092 kJ/mol-atom | 0 | DFT |  |  | [1] Li 2018 | Table 4, p. 6, row 12; `ORC-F6WUAXESL4.93d4ac` |  |

## Other properties

### Phase transition (12)

Table: Phase transition, Ag–Se system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Phase transition | 397.5 K | 397.5 | polymorphic: β-Ag2Se -> α-Ag2Se; _β-Ag2Se: Se 0.333; α-Ag2Se: Se 0.333333_ | experimental | [1] Li 2018; _cites Voronin 2011_ [doi](https://doi.org/10.1134/s1023193511040203) | Table 6, p. 9, row 17; `ORC-K4KNGG5MBZ` |  |
| Phase transition | 405.4 K | 405.4 | polymorphic: β-Ag2Se -> α-Ag2Se; _β-Ag2Se: Se 0.333; α-Ag2Se: Se 0.333333_ | experimental | [1] Li 2018; _cites Osadchii 2007_ [doi](https://doi.org/10.2138/am.2007.2209) | Table 6, p. 9, row 15; `ORC-WVSW7E5KQR` |  |
| Phase transition | 405.42 K | 405.42 | polymorphic: β-Ag2Se -> α-Ag2Se; _β-Ag2Se: Se 0.333; α-Ag2Se: Se 0.333333_ | model | [1] Li 2018 | Table 6, p. 9, row 20; `ORC-KVVPZY5NC4` |  |
| Phase transition | 406 K | 406 | polymorphic: β-Ag2Se -> α-Ag2Se; _β-Ag2Se: Se 0.333; α-Ag2Se: Se 0.333333_ | experimental | [1] Li 2018; _cites Nasar 1997_ [doi](https://doi.org/10.1007/s11663-997-0120-5) | Table 6, p. 9, row 19; `ORC-2ZJPQBOXV2` |  |
| Phase transition | 406 K | 406 | polymorphic: β-Ag2Se -> α-Ag2Se; _β-Ag2Se: Se 0.333; α-Ag2Se: Se 0.333333_ | experimental | [1] Li 2018; _cites Olin 2005_ | Table 6, p. 9, row 16; `ORC-X2CSDMHGEC` |  |
| Phase transition | 407.7 K | 407.7 | polymorphic: β-Ag2Se -> α-Ag2Se; _β-Ag2Se: Se 0.333; α-Ag2Se: Se 0.333333_ | experimental | [1] Li 2018; _cites Feng 2013_ [doi](https://doi.org/10.1016/j.ssi.2012.10.013) | Table 6, p. 9, row 18; `ORC-VER7GHGEG6` |  |
| Phase transition | 1167 K | 1167 | congruent melting: L2 -> β-Ag2Se; _L2: Se 0.333; β-Ag2Se: Se 0.333333_ | experimental | [1] Li 2018; _cites Kulwicki 1963_ | Table 6, p. 9, row 9; `ORC-GZP36LH55D` |  |
| Phase transition | 1168 K | 1168 | congruent melting: L2 -> β-Ag2Se; _L2: Se 0.333; β-Ag2Se: Se 0.333333_ | experimental | [1] Li 2018; _cites Ohno 1994_ [doi](https://doi.org/10.1088/0953-8984/6/28/010) | Table 6, p. 9, row 8; `ORC-YULOY5UZWW` |  |
| Phase transition | 1170 K | 1170 | congruent melting: L2 -> β-Ag2Se; _L2: Se 0.333; β-Ag2Se: Se 0.333333_ | experimental | [1] Li 2018; _cites Pellini 1915_ | Table 6, p. 9, row 7; `ORC-ISLSPXP6JL` |  |
| Phase transition | 1170.12 K | 1170.12 | congruent melting: L2 -> β-Ag2Se; _L2: Se 0.333; β-Ag2Se: Se 0.333333_ | model | [1] Li 2018 | Table 6, p. 9, row 10; `ORC-IBJOJQBLZZ` |  |
| Phase transition | 1233.15 K | 1233.15 | Ag2Se3 | model | [2] Shi 2019; _cites Yaws 2015_ [doi](https://doi.org/10.1016/b978-0-12-800834-8.00002-5) | p. 4; `ORC-TXMTWDGJDK` | “Yaws\[29\] assessed the melting temperature of Ag2Se3 to be 960 C based on experimental values.” |
| Phase transition | 2096.26 K | 2096.26 | other | model | [1] Li 2018 | p. 8; `ORC-4GSNYIQGVA` | “The calculated miscibility gap in liquid phase converges at 2096.26 K, which agrees with the value of Wiggett et al.\[25\] in that the boundary of the miscibility gap does not converge even at relatively high temperature (\* 1450 K).” |

### Formation (16)

Table: Formation, Ag–Se system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Gibbs energy of formation; _printed: −ΔfG°_ | -16.4133 kJ/mol-atom | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Feng 2013_ [doi](https://doi.org/10.1016/j.ssi.2012.10.013) | Table 1, p. 3, row 8; `ORC-3HNT2KROYM.a2bfc1` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -16.49 kJ/mol-atom | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Osadchii 2007_ [doi](https://doi.org/10.2138/am.2007.2209) | Table 1, p. 3, row 1; `ORC-DENBWB3K3C.795a9d` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -16.49 kJ/mol-atom | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | model | [1] Li 2018 | Table 1, p. 3, row 9; `ORC-EG4CZFRGL7.ed96ac` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -16.53 kJ/mol-atom | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Voronin 2011_ [doi](https://doi.org/10.1134/s1023193511040203) | Table 1, p. 3, row 4; `ORC-IAHORPYKKP.dffef8` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -16.3967 kJ/mol-atom | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Voronin 2011_ [doi](https://doi.org/10.1134/s1023193511040203) | Table 1, p. 3, row 3; `ORC-IYYBFJIDJR.b0c51f` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -16.34 kJ/mol-atom | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Oehsen 1981_ [doi](https://doi.org/10.1002/bbpc.19810850104) | Table 1, p. 3, row 5; `ORC-N7ZOMZ7UNS.69f53d` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -16.3 kJ/mol-atom | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Nasar 1997_ [doi](https://doi.org/10.1007/s11663-997-0120-5) | Table 1, p. 3, row 2; `ORC-NOQDCUENTV.ece9ca` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -15.6333 kJ/mol-atom | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Olin 2005_ | Table 1, p. 3, row 6; `ORC-RMJA7ZD7GC.195be4` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -16.47 kJ/mol-atom | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Grnvold 2003_ [doi](https://doi.org/10.1016/s0040-6031%2802%2900470-7) | Table 1, p. 3, row 7; `ORC-S7IJ2WTKZG.c6a6ae` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -15.81 kJ/mol-atom | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Osadchii 2007_ [doi](https://doi.org/10.2138/am.2007.2209) | Table 1, p. 3, row 10; `ORC-DYLEZCG4HM.dda937` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -15.86 kJ/mol-atom | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Voronin 2011_ [doi](https://doi.org/10.1134/s1023193511040203) | Table 1, p. 3, row 11; `ORC-FCNMFTUR4E.92fd58` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -15.9567 kJ/mol-atom | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Nasar 1997_ [doi](https://doi.org/10.1007/s11663-997-0120-5) | Table 1, p. 3, row 15; `ORC-FORFJG353E.e63569` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -15.81 kJ/mol-atom | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | model | [1] Li 2018 | Table 1, p. 3, row 16; `ORC-G2E5AOIVAY.76a40b` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -15.8267 kJ/mol-atom | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Grnvold 2003_ [doi](https://doi.org/10.1016/s0040-6031%2802%2900470-7) | Table 1, p. 3, row 12; `ORC-IR25DWRF5G.53bf45` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -15.88 kJ/mol-atom | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Feng 2013_ [doi](https://doi.org/10.1016/j.ssi.2012.10.013) | Table 1, p. 3, row 13; `ORC-JFXIVMRCAO.b4f2b4` |  |
| Gibbs energy of formation; _printed: −ΔfG°_ | -15.84 kJ/mol-atom | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Oehsen 1981_ [doi](https://doi.org/10.1002/bbpc.19810850104) | Table 1, p. 3, row 14; `ORC-PJHC2KGG2M.c02e48` |  |

### Heat capacity / entropy / enthalpy (16)

Table: Heat capacity / entropy / enthalpy, Ag–Se system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Entropy; _printed: S°_ | 51.5333 J/mol-atom/K | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Feng 2013_ [doi](https://doi.org/10.1016/j.ssi.2012.10.013) | Table 1, p. 3, row 8; `ORC-3HNT2KROYM.990832` |  |
| Entropy; _printed: S°_ | 49.9967 J/mol-atom/K | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Osadchii 2007_ [doi](https://doi.org/10.2138/am.2007.2209) | Table 1, p. 3, row 1; `ORC-DENBWB3K3C.26b5f5` |  |
| Entropy; _printed: S°_ | 49.9933 J/mol-atom/K | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | model | [1] Li 2018 | Table 1, p. 3, row 9; `ORC-EG4CZFRGL7.099ba1` |  |
| Entropy; _printed: S°_ | 49.7333 J/mol-atom/K | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Voronin 2011_ [doi](https://doi.org/10.1134/s1023193511040203) | Table 1, p. 3, row 4; `ORC-IAHORPYKKP.afc82b` |  |
| Entropy; _printed: S°_ | 50.0267 J/mol-atom/K | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Voronin 2011_ [doi](https://doi.org/10.1134/s1023193511040203) | Table 1, p. 3, row 3; `ORC-IYYBFJIDJR.162e5c` |  |
| Entropy; _printed: S°_ | 51.8467 J/mol-atom/K | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Oehsen 1981_ [doi](https://doi.org/10.1002/bbpc.19810850104) | Table 1, p. 3, row 5; `ORC-N7ZOMZ7UNS.86de55` |  |
| Entropy; _printed: S°_ | 49.4 J/mol-atom/K | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Nasar 1997_ [doi](https://doi.org/10.1007/s11663-997-0120-5) | Table 1, p. 3, row 2; `ORC-NOQDCUENTV.d22ac6` |  |
| Entropy; _printed: S°_ | 49.9667 J/mol-atom/K | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Olin 2005_ | Table 1, p. 3, row 6; `ORC-RMJA7ZD7GC.480378` |  |
| Entropy; _printed: S°_ | 50.3433 J/mol-atom/K | 298.15 | α-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Grnvold 2003_ [doi](https://doi.org/10.1016/s0040-6031%2802%2900470-7) | Table 1, p. 3, row 7; `ORC-S7IJ2WTKZG.44d77f` |  |
| Entropy; _printed: S°_ | 56.3367 J/mol-atom/K | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Osadchii 2007_ [doi](https://doi.org/10.2138/am.2007.2209) | Table 1, p. 3, row 10; `ORC-DYLEZCG4HM.68f3c3` |  |
| Entropy; _printed: S°_ | 56.48 J/mol-atom/K | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Voronin 2011_ [doi](https://doi.org/10.1134/s1023193511040203) | Table 1, p. 3, row 11; `ORC-FCNMFTUR4E.5707ff` |  |
| Entropy; _printed: S°_ | 49.4 J/mol-atom/K | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Nasar 1997_ [doi](https://doi.org/10.1007/s11663-997-0120-5) | Table 1, p. 3, row 15; `ORC-FORFJG353E.ff2936` |  |
| Entropy; _printed: S°_ | 56.3333 J/mol-atom/K | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | model | [1] Li 2018 | Table 1, p. 3, row 16; `ORC-G2E5AOIVAY.3e13c8` |  |
| Entropy; _printed: S°_ | 56.3633 J/mol-atom/K | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Grnvold 2003_ [doi](https://doi.org/10.1016/s0040-6031%2802%2900470-7) | Table 1, p. 3, row 12; `ORC-IR25DWRF5G.fbd859` |  |
| Entropy; _printed: S°_ | 56.5233 J/mol-atom/K | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Feng 2013_ [doi](https://doi.org/10.1016/j.ssi.2012.10.013) | Table 1, p. 3, row 13; `ORC-JFXIVMRCAO.e9240b` |  |
| Entropy; _printed: S°_ | 56.46 J/mol-atom/K | 298.15 | β-Ag2Se; _alloy: Se 0.333333_ | experimental | [1] Li 2018; _cites Oehsen 1981_ [doi](https://doi.org/10.1002/bbpc.19810850104) | Table 1, p. 3, row 14; `ORC-PJHC2KGG2M.6ce77e` |  |

### Other property (1)

Table: Other property, Ag–Se system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Other; _printed: enthalpy_ | 7.71 kJ/mol | 405.42 |  | model | [1] Li 2018 | p. 10; `ORC-MZHW33WEFX` | “The temperature and enthalpy of a-Ag2Se to b-Ag2Se transformation are calculated as 405.42 K and 7.71 kJ/mol as shown in Table 6 and 2, respectively.” |

## 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. 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)

## 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/).