# Na–O–U system

> Na–O–U system: 179 accepted literature values (crystal structure 95, formation 35, heat capacity / entropy / enthalpy 34, invariant reaction 14) and 0 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

HTML: https://data.orchid-project.org/systems/NA-O-U.html · Markdown: https://data.orchid-project.org/systems/NA-O-U.md

179 accepted literature values from 1 paper(s) (experimental 85, model 31, DFT 28, unspecified 35); 0 calculated phase diagram(s). 6 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/NA-O-U.json) · [CSV](https://data.orchid-project.org/systems/NA-O-U.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#NA-O-U) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/NA-O-U.html) · [Markdown](https://data.orchid-project.org/systems/NA-O-U.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 85 |
| model | 31 |
| DFT | 28 |
| unspecified | 35 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| invariant reaction | 14 |
| formation | 35 |
| heat capacity / entropy / enthalpy | 34 |
| crystal structure | 95 |
| model expression | 1 |

## Invariant reactions (literature)

Table: Invariant reactions reported in the literature for the Na–O–U system (14)

| T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote |
|---:|---|---|---|---|---|---|
| 2532.4 | Na2UO4 = UO2 + 2Na(g) + O2(g) |  | model | [1] Smith 2017 | Table 12, p. 19, row 7; `ORC-JN3M7AQOOM` |  |
| 2476.2 | Na2U2O7 = Na2UO4 + UO2 + 1/2O2(g) |  | model | [1] Smith 2017 | Table 12, p. 19, row 9; `ORC-YZCC4SVYJX` |  |
| 2341.6 | Na4UO5 = Na2UO4 + 2Na(g) + 1/2O2(g) |  | model | [1] Smith 2017 | Table 12, p. 19, row 5; `ORC-2Q2QJIUVVC` |  |
| 1913.4 | Na2U2O7 = 2UO2 + 2Na(g) + 3/2O2(g) |  | model | [1] Smith 2017 | Table 12, p. 19, row 10; `ORC-L6IBKDBDC5` |  |
| 1827.1 | 2Na2UO4 = Na2U2O7 + 2Na(g) + 1/2O2(g) |  | model | [1] Smith 2017 | Table 12, p. 19, row 8; `ORC-U7RXTOTIS5` |  |
| 1756.3 | Na4UO5 = Na2UO4 + 2Na(g) + 1/2O2(g) |  | model | [1] Smith 2017 | Table 12, p. 19, row 6; `ORC-KPUJ3NTW6F` |  |
| 1701.9 | 2NaUO3 = Na2UO4 + UO2 |  | model | [1] Smith 2017 | Table 12, p. 19, row 1; `ORC-LQJ435NA2J` |  |
| 1645.6 | 3NaUO3 = Na2U2O7 + UO2 + Na(g) |  | model | [1] Smith 2017 | Table 12, p. 19, row 2; `ORC-TBBH74SGIL` |  |
| 1620 | Na2U2O7 = 2UO2 + 2Na(g) + 3/2O2(g) |  | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 12, p. 19, row 14; `ORC-4HD5NNHCJS` |  |
| 1550 | 3NaUO3 = Na2U2O7 + UO2 + Na(g) |  | experimental | [1] Smith 2017; _cites Smith 2014_ | Table 12, p. 19, row 11; `ORC-K22OCHIPZZ` |  |
| 1358.3 | 2Na3UO4 = Na4UO5 + UO2 + 2Na(g) + 1/2O2(g) |  | model | [1] Smith 2017 | Table 12, p. 19, row 3; `ORC-AI7IDCJBHH` |  |
| 1273 | Na4UO5 = NaUO3 + 3Na(g) + O2(g) |  | experimental | [1] Smith 2017; _cites Smith 2014_ | Table 12, p. 19, row 13; `ORC-4DQU5EEHC7` |  |
| 1173 | Na3UO4 = NaUO3 + 2Na(g) + 1/2O2(g) |  | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 12, p. 19, row 12; `ORC-52ZNXYAYPM` |  |
| 944.4 | 2Na3UO4 = Na4UO5 + UO2 + 2Na(g) + 1/2O2(g) |  | model | [1] Smith 2017 | Table 12, p. 19, row 4; `ORC-5QFE5VAFFS` |  |

## 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, Na–O–U system (18)

| Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote |
|---|---|---:|---:|---|---:|---:|---|---|---|
| Na4UO5 |  | -245.7 kJ/mol-atom | 298.15 | model |  |  | [1] Smith 2017 | Table 8, p. 12, row 8; `ORC-U35EJ3COUG.4d732a` |  |
| Na4UO5 |  | -245.7 kJ/mol-atom ± 0.22 | 298.15 | experimental |  |  | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 6; `ORC-UAK72SN4IB.351931` |  |
| Na4UO5 |  | -238.83 kJ/mol-atom | 298.15 | DFT |  |  | [1] Smith 2017 | Table 8, p. 12, row 7; `ORC-IQUKA2ZQMW.547eeb` |  |
| NaUO3 |  | -298.98 kJ/mol-atom | 298.15 | model |  |  | [1] Smith 2017 | Table 8, p. 12, row 15; `ORC-GHEOX6AVL7.d91c42` |  |
| NaUO3 |  | -298.98 kJ/mol-atom ± 2 | 298.15 | experimental |  |  | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 13; `ORC-KJVQY5PHBZ.233753` |  |
| NaUO3 |  | -298.92 kJ/mol-atom | 298.15 | DFT |  |  | [1] Smith 2017 | Table 8, p. 12, row 14; `ORC-E7RN5GEMPQ.c555c0` |  |
| α-Na2U2O7 |  | -291.255 kJ/mol-atom | 298.15 | model |  |  | [1] Smith 2017 | Table 8, p. 12, row 11; `ORC-IPSIRQQY3F.7fd3e1` |  |
| α-Na2U2O7 |  | -291.255 kJ/mol-atom ± 0.363636 | 298.15 | experimental |  |  | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 9; `ORC-QRFJ7MF5HX.c32090` |  |
| α-Na2U2O7 |  | -284.591 kJ/mol-atom | 298.15 | DFT |  |  | [1] Smith 2017 | Table 8, p. 12, row 10; `ORC-WIXFGZYLZ5.1d88ea` |  |
| α-Na2UO4 |  | -271.6 kJ/mol-atom | 298.15 | model |  |  | [1] Smith 2017 | Table 8, p. 12, row 3; `ORC-KT2I7KQ4ZC.afa2cf` |  |
| α-Na2UO4 |  | -271.1 kJ/mol-atom ± 0.5 | 298.15 | experimental |  |  | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 1; `ORC-NBACGHOUKT.34730b` |  |
| α-Na2UO4 |  | -265.443 kJ/mol-atom | 298.15 | DFT |  |  | [1] Smith 2017 | Table 8, p. 12, row 2; `ORC-Z5TNUF2QYD.8dc057` |  |
| α-Na3UO4 |  | -253 kJ/mol-atom ± 1 | 298.15 | experimental |  |  | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 16; `ORC-MAEM6HMSSE.89d71d` |  |
| α-Na3UO4 |  | -253 kJ/mol-atom | 298.15 | model |  |  | [1] Smith 2017 | Table 8, p. 12, row 18; `ORC-U6FN5KA3UD.139f5b` |  |
| α-Na3UO4 |  | -251.838 kJ/mol-atom | 298.15 | DFT |  |  | [1] Smith 2017 | Table 8, p. 12, row 17; `ORC-XS6Z6HN5SC.2fc393` |  |
| β-Na2U2O7 |  | -284.618 kJ/mol-atom | 298.15 | DFT |  |  | [1] Smith 2017 | Table 8, p. 12, row 12; `ORC-B2U7BMSEFS.313e41` |  |
| β-Na2UO4 |  | -269.229 kJ/mol-atom ± 0.514286 | 298.15 | experimental |  |  | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 4; `ORC-L5WKOUAPR7` |  |
| β-Na2UO4 |  | -264.6 kJ/mol-atom | 298.15 | DFT |  |  | [1] Smith 2017 | Table 8, p. 12, row 5; `ORC-36VRI4S3TK.9edd93` |  |

## Other properties

### Formation (17)

Table: Formation, Na–O–U system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -223.47 kJ/mol-atom | 298.15 | Na4UO5; _alloy: O 0.5, U 0.1_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 7; `ORC-IQUKA2ZQMW.48c01a` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -230.17 kJ/mol-atom | 298.15 | Na4UO5; _alloy: O 0.5, U 0.1_ | model | [1] Smith 2017 | Table 8, p. 12, row 8; `ORC-U35EJ3COUG.a595a4` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -230.17 kJ/mol-atom ± 0.29 | 298.15 | Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 6; `ORC-UAK72SN4IB.882fec` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -282.54 kJ/mol-atom | 298.15 | NaUO3; _alloy: O 0.6, U 0.2_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 14; `ORC-E7RN5GEMPQ.be8b2e` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -282.16 kJ/mol-atom | 298.15 | NaUO3; _alloy: O 0.6, U 0.2_ | model | [1] Smith 2017 | Table 8, p. 12, row 15; `ORC-GHEOX6AVL7.f02a31` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -282.5 kJ/mol-atom ± 2 | 298.15 | NaUO3; _alloy: O 0.6, U 0.2_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 13; `ORC-KJVQY5PHBZ.1f4f9d` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -273.773 kJ/mol-atom | 298.15 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | model | [1] Smith 2017 | Table 8, p. 12, row 11; `ORC-IPSIRQQY3F.d02661` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -273.773 kJ/mol-atom ± 0.363636 | 298.15 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 9; `ORC-QRFJ7MF5HX.d51bb5` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -284.591 kJ/mol-atom | 298.15 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 10; `ORC-WIXFGZYLZ5.9780f3` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -254.857 kJ/mol-atom | 298.15 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | model | [1] Smith 2017 | Table 8, p. 12, row 3; `ORC-KT2I7KQ4ZC.fdec55` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -254.186 kJ/mol-atom ± 0.5 | 298.15 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 1; `ORC-NBACGHOUKT.0694fd` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -249.643 kJ/mol-atom | 298.15 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 2; `ORC-Z5TNUF2QYD.86a7c2` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -237.488 kJ/mol-atom ± 1 | 298.15 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 16; `ORC-MAEM6HMSSE.6cd241` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -237.488 kJ/mol-atom | 298.15 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | model | [1] Smith 2017 | Table 8, p. 12, row 18; `ORC-U6FN5KA3UD.4036a6` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -236.65 kJ/mol-atom | 298.15 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 17; `ORC-XS6Z6HN5SC.53564a` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -268.1 kJ/mol-atom | 298.15 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 12; `ORC-B2U7BMSEFS.30d912` |  |
| Gibbs energy of formation; _printed: ΔfG°m(298.15 K)_ | -248.414 kJ/mol-atom | 298.15 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 5; `ORC-36VRI4S3TK.752450` |  |

### Heat capacity / entropy / enthalpy (34)

Table: Heat capacity / entropy / enthalpy, Na–O–U system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Entropy; _printed: S°m(298.15 K)_ | 25.24 J/mol-atom/K | 298.15 | Na4UO5; _alloy: O 0.5, U 0.1_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 7; `ORC-IQUKA2ZQMW.804ad4` |  |
| Entropy; _printed: S°m(298.15 K)_ | 24.75 J/mol-atom/K | 298.15 | Na4UO5; _alloy: O 0.5, U 0.1_ | model | [1] Smith 2017 | Table 8, p. 12, row 8; `ORC-U35EJ3COUG.9d01ca` |  |
| Entropy; _printed: S°m(298.15 K)_ | 24.75 J/mol-atom/K ± 0.62 | 298.15 | Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 6; `ORC-UAK72SN4IB.02a81e` |  |
| Entropy; _printed: S°m(298.15 K)_ | 26.86 J/mol-atom/K | 298.15 | NaUO3; _alloy: O 0.6, U 0.2_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 14; `ORC-E7RN5GEMPQ.315c76` |  |
| Entropy; _printed: S°m(298.15 K)_ | 25.4 J/mol-atom/K | 298.15 | NaUO3; _alloy: O 0.6, U 0.2_ | model | [1] Smith 2017 | Table 8, p. 12, row 15; `ORC-GHEOX6AVL7.1e421c` |  |
| Entropy; _printed: S°m(298.15 K)_ | 26.56 J/mol-atom/K ± 0.08 | 298.15 | NaUO3; _alloy: O 0.6, U 0.2_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 13; `ORC-KJVQY5PHBZ.37210f` |  |
| Entropy; _printed: S°m(298.15 K)_ | 25.0818 J/mol-atom/K | 298.15 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | model | [1] Smith 2017 | Table 8, p. 12, row 11; `ORC-IPSIRQQY3F.4ec9f3` |  |
| Entropy; _printed: S°m(298.15 K)_ | 25.0818 J/mol-atom/K ± 0.0909091 | 298.15 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 9; `ORC-QRFJ7MF5HX.96ec3f` |  |
| Entropy; _printed: S°m(298.15 K)_ | 30.1182 J/mol-atom/K | 298.15 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 10; `ORC-WIXFGZYLZ5.90b033` |  |
| Entropy; _printed: S°m(298.15 K)_ | 24.2857 J/mol-atom/K | 298.15 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | model | [1] Smith 2017 | Table 8, p. 12, row 3; `ORC-KT2I7KQ4ZC.94e7d9` |  |
| Entropy; _printed: S°m(298.15 K)_ | 23.7143 J/mol-atom/K ± 0.0714286 | 298.15 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 1; `ORC-NBACGHOUKT.493dd6` |  |
| Entropy; _printed: S°m(298.15 K)_ | 27.3571 J/mol-atom/K | 298.15 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 2; `ORC-Z5TNUF2QYD.5e1c2a` |  |
| Entropy; _printed: S°m(298.15 K)_ | 24.775 J/mol-atom/K ± 0.05 | 298.15 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 16; `ORC-MAEM6HMSSE.95cd53` |  |
| Entropy; _printed: S°m(298.15 K)_ | 24.775 J/mol-atom/K | 298.15 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | model | [1] Smith 2017 | Table 8, p. 12, row 18; `ORC-U6FN5KA3UD.94a7fa` |  |
| Entropy; _printed: S°m(298.15 K)_ | 25.7875 J/mol-atom/K | 298.15 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 17; `ORC-XS6Z6HN5SC.7e5399` |  |
| Entropy; _printed: S°m(298.15 K)_ | 28.2818 J/mol-atom/K | 298.15 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 12; `ORC-B2U7BMSEFS.85759c` |  |
| Entropy; _printed: S°m(298.15 K)_ | 25.9714 J/mol-atom/K | 298.15 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 5; `ORC-36VRI4S3TK.a2a4b7` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 21.69 J/mol-atom/K | 298.15 | Na4UO5; _alloy: O 0.5, U 0.1_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 7; `ORC-IQUKA2ZQMW.0b6ffd` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 22.04 J/mol-atom/K | 298.15 | Na4UO5; _alloy: O 0.5, U 0.1_ | model | [1] Smith 2017 | Table 8, p. 12, row 8; `ORC-U35EJ3COUG.b180fb` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 22.06 J/mol-atom/K ± 0.67 | 298.15 | Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 6; `ORC-UAK72SN4IB.c84ed4` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 21.96 J/mol-atom/K | 298.15 | NaUO3; _alloy: O 0.6, U 0.2_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 14; `ORC-E7RN5GEMPQ.183f2c` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 21.82 J/mol-atom/K | 298.15 | NaUO3; _alloy: O 0.6, U 0.2_ | model | [1] Smith 2017 | Table 8, p. 12, row 15; `ORC-GHEOX6AVL7.7310d9` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 21.774 J/mol-atom/K ± 0.08 | 298.15 | NaUO3; _alloy: O 0.6, U 0.2_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 13; `ORC-KJVQY5PHBZ.39b1dd` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 20.7364 J/mol-atom/K | 298.15 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | model | [1] Smith 2017 | Table 8, p. 12, row 11; `ORC-IPSIRQQY3F.a72e3a` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 20.6636 J/mol-atom/K ± 0.0909091 | 298.15 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 9; `ORC-QRFJ7MF5HX.aea61c` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 20.8636 J/mol-atom/K | 298.15 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 10; `ORC-WIXFGZYLZ5.cb9e89` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 21.0143 J/mol-atom/K | 298.15 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | model | [1] Smith 2017 | Table 8, p. 12, row 3; `ORC-KT2I7KQ4ZC.6a33d8` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 20.9571 J/mol-atom/K ± 0.0714286 | 298.15 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 1; `ORC-NBACGHOUKT.56be8c` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 21.4571 J/mol-atom/K | 298.15 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 2; `ORC-Z5TNUF2QYD.3b072f` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 21.625 J/mol-atom/K ± 0.05 | 298.15 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Guillaumont 2003_ | Table 8, p. 12, row 16; `ORC-MAEM6HMSSE.ef77a9` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 21.6 J/mol-atom/K | 298.15 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | model | [1] Smith 2017 | Table 8, p. 12, row 18; `ORC-U6FN5KA3UD.1edfff` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 21.9625 J/mol-atom/K | 298.15 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 17; `ORC-XS6Z6HN5SC.ea79c5` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 20.9636 J/mol-atom/K | 298.15 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 12; `ORC-B2U7BMSEFS.327693` |  |
| Heat capacity; _printed: C°p,m(298.15 K)_ | 21.4429 J/mol-atom/K | 298.15 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | DFT | [1] Smith 2017 | Table 8, p. 12, row 5; `ORC-36VRI4S3TK.19086d` |  |

### Crystal structure (95)

Table: Crystal structure, Na–O–U system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 7.695 Å | 0 | Na4UO5; _alloy: O 0.5, U 0.1_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 14; `ORC-2PO6UOZQ6D.64d9ab` |  |
| Lattice a | 5.8321 Å | 0 | NaUO3; _alloy: O 0.6, U 0.2_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 2; `ORC-WRIULLBTMZ.85192a` |  |
| Lattice a | 13.1322 Å | 0 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 16; `ORC-POUD4MEIFR.2a78e5` |  |
| Lattice a | 10.0103 Å | 0 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 9; `ORC-6HWM5GHCWK.37c2dc` |  |
| Lattice a | 5.937 Å | 0 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 5; `ORC-2EOEFM3QXE.bcf1db` |  |
| Lattice a | 13.125 Å | 0 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 18; `ORC-2K5WLKS7O7.1f9dad` |  |
| Lattice a | 5.8598 Å | 0 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 11; `ORC-SSMGCBGUOB.095149` |  |
| Lattice a | 12.7617 Å ± 1.400e-4 | 293 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites IJdo 2015_ [doi](https://doi.org/10.1016/j.jssc.2014.09.011) | Table 10, p. 13, row 15; `ORC-DKOLOD5UMU.bd5a0a` |  |
| Lattice a | 7.5172 Å ± 1.000e-4 | 295 | Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Roof 2010_ [doi](https://doi.org/10.1016/j.jcrysgro.2009.12.002) | Table 10, p. 13, row 13; `ORC-VO2P2UAUJY.d94624` |  |
| Lattice a | 5.7739 Å ± 2.000e-4 | 295 | NaUO3; _alloy: O 0.6, U 0.2_ | experimental | [1] Smith 2017; _cites Van 2004_ [doi](https://doi.org/10.1016/j.jssc.2004.02.021) | Table 10, p. 13, row 1; `ORC-JE5SV5P2SX.041aaa` |  |
| Lattice a | 4.77 Å ± 0.02 | 295 | m-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Scholder 1964_ [doi](https://doi.org/10.1002/zaac.19643270104) | Table 10, p. 13, row 3; `ORC-QES4CX5PAG.339b60` |  |
| Lattice a | 4.764 Å ± 0.003 | 295 | m-Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 12; `ORC-DJKJXB3HQ7.6c0e32` |  |
| Lattice a | 9.7623 Å ± 3.000e-4 | 295 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Cordfunke 1995_ [doi](https://doi.org/10.1006/jssc.1995.1137) | Table 10, p. 13, row 8; `ORC-WVWM6UK62A.befcfa` |  |
| Lattice a | 5.892 Å ± 0.002 | 295 | α-Na3.16(2)U0.84(2)O4; _alloy: O 0.5, U 0.105_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 4; `ORC-FJEPEE7TP7.d25c9b` |  |
| Lattice a | 5.8079 Å ± 3.000e-4 | 295 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Cordfunke 1995_ [doi](https://doi.org/10.1006/jssc.1995.1137) | Table 10, p. 13, row 10; `ORC-WUP2RBOGWG.c7ece6` |  |
| Lattice a | 9.589 Å ± 0.002 | 295 | β-Na3+xU1-xO4 | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 6; `ORC-YS4AAIAIOZ.340cd9` |  |
| Lattice a | 9.56 Å ± 0.04 | 295 | β-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Marcon 1972_ | Table 10, p. 13, row 7; `ORC-N5MZ7PHZEY.ed6301` |  |
| Lattice a | 12.933 Å ± 0.001 | 773 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites IJdo 2015_ [doi](https://doi.org/10.1016/j.jssc.2014.09.011) | Table 10, p. 13, row 17; `ORC-LRXWCMSQFR.736da1` |  |
| Lattice a | 3.987 Å ± 0.003 | 1323 | γ-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 19; `ORC-FWMGNN3TZV.9b4a6c` |  |
| Lattice b | 7.695 Å | 0 | Na4UO5; _alloy: O 0.5, U 0.1_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 14; `ORC-2PO6UOZQ6D.34d447` |  |
| Lattice b | 5.9742 Å | 0 | NaUO3; _alloy: O 0.6, U 0.2_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 2; `ORC-WRIULLBTMZ.b057b7` |  |
| Lattice b | 7.8815 Å | 0 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 16; `ORC-POUD4MEIFR.c0964c` |  |
| Lattice b | 5.7628 Å | 0 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 9; `ORC-6HWM5GHCWK.45bf93` |  |
| Lattice b | 6.845 Å | 0 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 5; `ORC-2EOEFM3QXE.f14327` |  |
| Lattice b | 7.881 Å | 0 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 18; `ORC-2K5WLKS7O7.6d6df5` |  |
| Lattice b | 6.0265 Å | 0 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 11; `ORC-SSMGCBGUOB.e4638b` |  |
| Lattice b | 7.8384 Å ± 1.000e-4 | 293 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites IJdo 2015_ [doi](https://doi.org/10.1016/j.jssc.2014.09.011) | Table 10, p. 13, row 15; `ORC-DKOLOD5UMU.a84424` |  |
| Lattice b | 7.5172 Å ± 1.000e-4 | 295 | Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Roof 2010_ [doi](https://doi.org/10.1016/j.jcrysgro.2009.12.002) | Table 10, p. 13, row 13; `ORC-VO2P2UAUJY.8167c9` |  |
| Lattice b | 5.9051 Å ± 2.000e-4 | 295 | NaUO3; _alloy: O 0.6, U 0.2_ | experimental | [1] Smith 2017; _cites Van 2004_ [doi](https://doi.org/10.1016/j.jssc.2004.02.021) | Table 10, p. 13, row 1; `ORC-JE5SV5P2SX.87ba26` |  |
| Lattice b | 4.77 Å ± 0.02 | 295 | m-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Scholder 1964_ [doi](https://doi.org/10.1002/zaac.19643270104) | Table 10, p. 13, row 3; `ORC-QES4CX5PAG.585aa6` |  |
| Lattice b | 4.764 Å ± 0.003 | 295 | m-Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 12; `ORC-DJKJXB3HQ7.da3221` |  |
| Lattice b | 5.7287 Å ± 2.000e-4 | 295 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Cordfunke 1995_ [doi](https://doi.org/10.1006/jssc.1995.1137) | Table 10, p. 13, row 8; `ORC-WVWM6UK62A.700dba` |  |
| Lattice b | 6.772 Å ± 0.002 | 295 | α-Na3.16(2)U0.84(2)O4; _alloy: O 0.5, U 0.105_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 4; `ORC-FJEPEE7TP7.a84bfc` |  |
| Lattice b | 5.9753 Å ± 3.000e-4 | 295 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Cordfunke 1995_ [doi](https://doi.org/10.1006/jssc.1995.1137) | Table 10, p. 13, row 10; `ORC-WUP2RBOGWG.49abb5` |  |
| Lattice b | 9.589 Å ± 0.002 | 295 | β-Na3+xU1-xO4 | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 6; `ORC-YS4AAIAIOZ.3474d9` |  |
| Lattice b | 9.56 Å ± 0.04 | 295 | β-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Marcon 1972_ | Table 10, p. 13, row 7; `ORC-N5MZ7PHZEY.9fd134` |  |
| Lattice b | 7.887 Å ± 0.001 | 773 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites IJdo 2015_ [doi](https://doi.org/10.1016/j.jssc.2014.09.011) | Table 10, p. 13, row 17; `ORC-LRXWCMSQFR.3ff921` |  |
| Lattice b | 3.987 Å ± 0.003 | 1323 | γ-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 19; `ORC-FWMGNN3TZV.ce2a85` |  |
| Lattice c | 4.6325 Å | 0 | Na4UO5; _alloy: O 0.5, U 0.1_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 14; `ORC-2PO6UOZQ6D.e71dc7` |  |
| Lattice c | 8.3699 Å | 0 | NaUO3; _alloy: O 0.6, U 0.2_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 2; `ORC-WRIULLBTMZ.549282` |  |
| Lattice c | 6.9292 Å | 0 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 16; `ORC-POUD4MEIFR.edc1e4` |  |
| Lattice c | 3.5236 Å | 0 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 9; `ORC-6HWM5GHCWK.53c3ab` |  |
| Lattice c | 5.978 Å | 0 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 5; `ORC-2EOEFM3QXE.4b4dd3` |  |
| Lattice c | 6.9291 Å | 0 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 18; `ORC-2K5WLKS7O7.f65bae` |  |
| Lattice c | 11.8836 Å | 0 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 11; `ORC-SSMGCBGUOB.86c218` |  |
| Lattice c | 6.8962 Å ± 9.000e-4 | 293 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites IJdo 2015_ [doi](https://doi.org/10.1016/j.jssc.2014.09.011) | Table 10, p. 13, row 15; `ORC-DKOLOD5UMU.d2e6ff` |  |
| Lattice c | 4.6325 Å ± 2.000e-4 | 295 | Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Roof 2010_ [doi](https://doi.org/10.1016/j.jcrysgro.2009.12.002) | Table 10, p. 13, row 13; `ORC-VO2P2UAUJY.5925f2` |  |
| Lattice c | 8.2784 Å ± 2.000e-4 | 295 | NaUO3; _alloy: O 0.6, U 0.2_ | experimental | [1] Smith 2017; _cites Van 2004_ [doi](https://doi.org/10.1016/j.jssc.2004.02.021) | Table 10, p. 13, row 1; `ORC-JE5SV5P2SX.7a8b20` |  |
| Lattice c | 4.77 Å ± 0.02 | 295 | m-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Scholder 1964_ [doi](https://doi.org/10.1002/zaac.19643270104) | Table 10, p. 13, row 3; `ORC-QES4CX5PAG.e49a44` |  |
| Lattice c | 4.764 Å ± 0.003 | 295 | m-Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 12; `ORC-DJKJXB3HQ7.bae558` |  |
| Lattice c | 3.4956 Å ± 1.000e-4 | 295 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Cordfunke 1995_ [doi](https://doi.org/10.1006/jssc.1995.1137) | Table 10, p. 13, row 8; `ORC-WVWM6UK62A.a84382` |  |
| Lattice c | 5.916 Å ± 0.002 | 295 | α-Na3.16(2)U0.84(2)O4; _alloy: O 0.5, U 0.105_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 4; `ORC-FJEPEE7TP7.e798bf` |  |
| Lattice c | 11.7179 Å ± 6.000e-4 | 295 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Cordfunke 1995_ [doi](https://doi.org/10.1006/jssc.1995.1137) | Table 10, p. 13, row 10; `ORC-WUP2RBOGWG.fe0b3d` |  |
| Lattice c | 9.589 Å ± 0.002 | 295 | β-Na3+xU1-xO4 | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 6; `ORC-YS4AAIAIOZ.4665f2` |  |
| Lattice c | 9.56 Å ± 0.04 | 295 | β-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Marcon 1972_ | Table 10, p. 13, row 7; `ORC-N5MZ7PHZEY.97213c` |  |
| Lattice c | 6.9086 Å ± 8.000e-4 | 773 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites IJdo 2015_ [doi](https://doi.org/10.1016/j.jssc.2014.09.011) | Table 10, p. 13, row 17; `ORC-LRXWCMSQFR.d3d59b` |  |
| Lattice c | 18.491 Å ± 0.003 | 1323 | γ-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 19; `ORC-FWMGNN3TZV.b826b7` |  |
| lattice beta | 90 ° | 0 | Na4UO5; _alloy: O 0.5, U 0.1_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 14; `ORC-2PO6UOZQ6D.f44760` |  |
| lattice beta | 90 ° | 0 | NaUO3; _alloy: O 0.6, U 0.2_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 2; `ORC-WRIULLBTMZ.9d2adf` |  |
| lattice beta | 110.994 ° | 0 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 16; `ORC-POUD4MEIFR.fbe418` |  |
| lattice beta | 90 ° | 0 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 9; `ORC-6HWM5GHCWK.ba33be` |  |
| lattice beta | 110.54 ° | 0 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 5; `ORC-2EOEFM3QXE.30e672` |  |
| lattice beta | 110.967 ° | 0 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 18; `ORC-2K5WLKS7O7.63661a` |  |
| lattice beta | 90 ° | 0 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 11; `ORC-SSMGCBGUOB.f011c6` |  |
| lattice beta | 111.285 ° ± 0.009 | 293 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites IJdo 2015_ [doi](https://doi.org/10.1016/j.jssc.2014.09.011) | Table 10, p. 13, row 15; `ORC-DKOLOD5UMU.2874fd` |  |
| lattice beta | 90 ° | 295 | Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Roof 2010_ [doi](https://doi.org/10.1016/j.jcrysgro.2009.12.002) | Table 10, p. 13, row 13; `ORC-VO2P2UAUJY.46c6b4` |  |
| lattice beta | 90 ° | 295 | NaUO3; _alloy: O 0.6, U 0.2_ | experimental | [1] Smith 2017; _cites Van 2004_ [doi](https://doi.org/10.1016/j.jssc.2004.02.021) | Table 10, p. 13, row 1; `ORC-JE5SV5P2SX.52c8cf` |  |
| lattice beta | 90 ° | 295 | m-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Scholder 1964_ [doi](https://doi.org/10.1002/zaac.19643270104) | Table 10, p. 13, row 3; `ORC-QES4CX5PAG.b5dde3` |  |
| lattice beta | 90 ° | 295 | m-Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 12; `ORC-DJKJXB3HQ7.2ec493` |  |
| lattice beta | 90 ° | 295 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Cordfunke 1995_ [doi](https://doi.org/10.1006/jssc.1995.1137) | Table 10, p. 13, row 8; `ORC-WVWM6UK62A.daf05e` |  |
| lattice beta | 110.65 ° ± 0.02 | 295 | α-Na3.16(2)U0.84(2)O4; _alloy: O 0.5, U 0.105_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 4; `ORC-FJEPEE7TP7.b40069` |  |
| lattice beta | 90 ° | 295 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Cordfunke 1995_ [doi](https://doi.org/10.1006/jssc.1995.1137) | Table 10, p. 13, row 10; `ORC-WUP2RBOGWG.4221e1` |  |
| lattice beta | 90 ° | 295 | β-Na3+xU1-xO4 | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 6; `ORC-YS4AAIAIOZ.390677` |  |
| lattice beta | 90 ° | 295 | β-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Marcon 1972_ | Table 10, p. 13, row 7; `ORC-N5MZ7PHZEY.c191f4` |  |
| lattice beta | 110.816 ° ± 0.01 | 773 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites IJdo 2015_ [doi](https://doi.org/10.1016/j.jssc.2014.09.011) | Table 10, p. 13, row 17; `ORC-LRXWCMSQFR.f0621d` |  |
| lattice beta | 90 ° | 1323 | γ-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 19; `ORC-FWMGNN3TZV.cce032` |  |
| lattice v | 0.27542 nm3 | 0 | Na4UO5; _alloy: O 0.5, U 0.1_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 14; `ORC-2PO6UOZQ6D.ef1d23` |  |
| lattice v | 0.29187 nm3 | 0 | NaUO3; _alloy: O 0.6, U 0.2_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 2; `ORC-WRIULLBTMZ.d9d13a` |  |
| lattice v | 0.66918 nm3 | 0 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 16; `ORC-POUD4MEIFR.981e01` |  |
| lattice v | 0.203352 nm3 | 0 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 9; `ORC-6HWM5GHCWK.697fe5` |  |
| lattice v | 0.2273 nm3 | 0 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 5; `ORC-2EOEFM3QXE.68e6cd` |  |
| lattice v | 0.66933 nm3 | 0 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 18; `ORC-2K5WLKS7O7.74bc3f` |  |
| lattice v | 0.419514 nm3 | 0 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | unspecified | [1] Smith 2017 | Table 10, p. 13, row 11; `ORC-SSMGCBGUOB.af2ace` |  |
| lattice v | 0.64278 nm3 ± 1.000e-4 | 293 | α-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites IJdo 2015_ [doi](https://doi.org/10.1016/j.jssc.2014.09.011) | Table 10, p. 13, row 15; `ORC-DKOLOD5UMU.3a57da` |  |
| lattice v | 0.26178 nm3 ± 1.000e-5 | 295 | Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Roof 2010_ [doi](https://doi.org/10.1016/j.jcrysgro.2009.12.002) | Table 10, p. 13, row 13; `ORC-VO2P2UAUJY.e574c4` |  |
| lattice v | 0.28226 nm3 ± 1.000e-5 | 295 | NaUO3; _alloy: O 0.6, U 0.2_ | experimental | [1] Smith 2017; _cites Van 2004_ [doi](https://doi.org/10.1016/j.jssc.2004.02.021) | Table 10, p. 13, row 1; `ORC-JE5SV5P2SX.340530` |  |
| lattice v | 0.10853 nm3 ± 1.000e-4 | 295 | m-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Scholder 1964_ [doi](https://doi.org/10.1002/zaac.19643270104) | Table 10, p. 13, row 3; `ORC-QES4CX5PAG.316108` |  |
| lattice v | 0.10812 nm3 ± 1.000e-5 | 295 | m-Na4UO5; _alloy: O 0.5, U 0.1_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 12; `ORC-DJKJXB3HQ7.c043f2` |  |
| lattice v | 0.195496 nm3 ± 1.100e-5 | 295 | α-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Cordfunke 1995_ [doi](https://doi.org/10.1006/jssc.1995.1137) | Table 10, p. 13, row 8; `ORC-WVWM6UK62A.736fa7` |  |
| lattice v | 0.22083 nm3 ± 1.000e-5 | 295 | α-Na3.16(2)U0.84(2)O4; _alloy: O 0.5, U 0.105_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 4; `ORC-FJEPEE7TP7.93ebb4` |  |
| lattice v | 0.40665 nm3 ± 3.400e-5 | 295 | β-Na2UO4; _alloy: O 0.571429, U 0.142857_ | experimental | [1] Smith 2017; _cites Cordfunke 1995_ [doi](https://doi.org/10.1006/jssc.1995.1137) | Table 10, p. 13, row 10; `ORC-WUP2RBOGWG.a5267d` |  |
| lattice v | 0.88191 nm3 ± 1.000e-5 | 295 | β-Na3+xU1-xO4 | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 6; `ORC-YS4AAIAIOZ.7c1c27` |  |
| lattice v | 0.8737 nm3 ± 1.000e-4 | 295 | β-Na3UO4; _alloy: O 0.5, U 0.125_ | experimental | [1] Smith 2017; _cites Marcon 1972_ | Table 10, p. 13, row 7; `ORC-N5MZ7PHZEY.3e0ee7` |  |
| lattice v | 0.6588 nm3 ± 1.300e-4 | 773 | β-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites IJdo 2015_ [doi](https://doi.org/10.1016/j.jssc.2014.09.011) | Table 10, p. 13, row 17; `ORC-LRXWCMSQFR.bc85eb` |  |
| lattice v | 0.25461 nm3 ± 1.000e-5 | 1323 | γ-Na2U2O7; _alloy: O 0.636364, U 0.181818_ | experimental | [1] Smith 2017; _cites Smith 2015_ [doi](https://doi.org/10.1021/acs.inorgchem.5b00136) | Table 10, p. 13, row 19; `ORC-FWMGNN3TZV.c7c94c` |  |

### Model expression (1)

Table: Model expression, Na–O–U system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Chemical potential; _printed: ΔG_O2^eq (T/K)_ | expression: −948630 + 263.28T | 900 | α-Na3UO4; _alloy: O 0.5, U 0.125_ | model | [1] Smith 2017 | Table 13, p. 20, row 7; `ORC-3BIODAA54I` |  |

## Sources

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

1. A.L. Smith, C. Guéneau, J.-L. Flèche, S. Chatain, O. Beneš, R.J.M. Konings, Thermodynamic assessment of the Na-O and Na-U-O systems: Margin to the safe operation of SFRs, The Journal of Chemical Thermodynamics 114, 93-115 (2017). [doi:10.1016/j.jct.2017.04.003](https://doi.org/10.1016/j.jct.2017.04.003)

## 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/).