# Ta–V system

> Ta–V system: 128 accepted literature values (crystal structure 105, phase transition 13, formation 5, invariant reaction 4) and 5 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote.

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

128 accepted literature values from 3 paper(s) (experimental 39, model 14, DFT 72, unspecified 3); 5 calculated phase diagram(s). 3 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/TA-V.json) · [CSV](https://data.orchid-project.org/systems/TA-V.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#TA-V) · [interactive phase diagram](https://orchid-project.org/phase-diagrams/#TA-V/TaV-04Dan-LB.json) · [phases (6)](https://data.orchid-project.org/phases/pages/TA-V.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/TA-V.html) · [Markdown](https://data.orchid-project.org/systems/TA-V.md)

Table: Accepted values by evidence class

| Evidence class | Values |
|---|---:|
| experimental | 39 |
| model | 14 |
| DFT | 72 |
| unspecified | 3 |

Table: Accepted values by property group

| Property group | Values |
|---|---:|
| invariant reaction | 4 |
| phase transition | 13 |
| formation | 5 |
| mixing / partial | 1 |
| crystal structure | 105 |

## 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 |
|---|---|---|---|
| TaV-04Dan-LB.tdb | C.A. Danon, C. Servant, J. Alloys Compd., 366, 191-200(2004). [doi:10.1016/S0925-8388(03)00728-X](https://doi.org/10.1016/S0925-8388%2803%2900728-X) | `759e7fab83f6768c8ba3cc1bc1b360cce5efe1f8f2145e7998dc039493febbcc` | [viewer](https://orchid-project.org/phase-diagrams/#TA-V/TaV-04Dan-LB.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/TaV-04Dan-LB.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/TaV-04Dan-LB.json) |
| TaV-04Dan-final.tdb | C.A. Danon, C. Servant, J. Alloys Compd., 366, 191-200(2004). [doi:10.1016/S0925-8388(03)00728-X](https://doi.org/10.1016/S0925-8388%2803%2900728-X) | `e087735be882c734158b1418f36ff6b247144d5801e36144bec1354ccab56199` | [viewer](https://orchid-project.org/phase-diagrams/#TA-V/TaV-04Dan-final.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/TaV-04Dan-final.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/TaV-04Dan-final.json) |
| TaV-11Pav-3sl.tdb | J. Pavlu, J. Vrestal, X.-Q. Chen, P. Rogl, Calphad, 35, 103-8(2011). [doi:10.1016/j.calphad.2010.12.002](https://doi.org/10.1016/j.calphad.2010.12.002) | `14fb4f3a13ba57e1b06d3c6c2c609cd63b6dcea149ab805026cc6eb8bd47ae0d` | [viewer](https://orchid-project.org/phase-diagrams/#TA-V/TaV-11Pav-3sl.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/TaV-11Pav-3sl.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/TaV-11Pav-3sl.json) |
| TaV-11Pav.tdb | J. Pavlu, J. Vrestal, X.-Q. Chen, P. Rogl, Calphad, 35, 103-8(2011). [doi:10.1016/j.calphad.2010.12.002](https://doi.org/10.1016/j.calphad.2010.12.002) | `773e8a82344b28f3e739a61c9b5a540002e0448854ce38bf3e2ce9493baa5609` | [viewer](https://orchid-project.org/phase-diagrams/#TA-V/TaV-11Pav.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/TaV-11Pav.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/TaV-11Pav.json) |
| TaV-13Bro.tdb | P. Broz, A.U. Khan, H. Niu, X.-Q. Chen, D. Li, J. Vrestal, J. Bursik, P. Rogl, J. Solid Stae Chem., 199, 171-80(2013). [doi:10.1016/j.jssc.2012.12.003](https://doi.org/10.1016/j.jssc.2012.12.003) | `f220800583236b2b9725c30dbe0c178a25c381e9b58301bc881799758aa4a073` | [viewer](https://orchid-project.org/phase-diagrams/#TA-V/TaV-13Bro.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/TaV-13Bro.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/TaV-13Bro.json) |

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

| TDB file | T (K) | Phases at the invariant |
|---|---:|---|
| TaV-04Dan-final.tdb | 1550.16 | BCC_A2 (x(V) 0.49715) + C15_LAVES (x(V) 0.62646) + C14_LAVES (x(V) 0.64025) |
| TaV-04Dan-final.tdb | 1403.03 | C15_LAVES (x(V) 0.68706) + C14_LAVES (x(V) 0.68981) + BCC_A2 (x(V) 0.93516) |
| TaV-11Pav-3sl.tdb | 1547.05 | BCC_A2 (x(V) 0.42079) + C15_LAVES (x(V) 0.62086) + C14_LAVES (x(V) 0.63932) |
| TaV-11Pav-3sl.tdb | 1405.16 | C15_LAVES (x(V) 0.68362) + C14_LAVES (x(V) 0.68934) + BCC_A2 (x(V) 0.96665) |
| TaV-11Pav-3sl.tdb | 643.35 | C15_LAVES (x(V) 0.66855) + C14_LAVES (x(V) 0.66872) + BCC_A2 (x(V) 0.99992) |
| TaV-11Pav-3sl.tdb | 602.17 | BCC_A2 (x(V) 0.10925) + C15_LAVES (x(V) 0.64983) + C14_LAVES (x(V) 0.65998) |
| TaV-11Pav.tdb | 1550.87 | BCC_A2 (x(V) 0.42392) + C15_LAVES (x(V) 0.62142) + C14_LAVES (x(V) 0.63798) |
| TaV-11Pav.tdb | 1405.18 | C15_LAVES (x(V) 0.68362) + C14_LAVES (x(V) 0.69305) + BCC_A2 (x(V) 0.96665) |
| TaV-11Pav.tdb | 626.13 | C15_LAVES (x(V) 0.66831) + C14_LAVES (x(V) 0.66925) + BCC_A2 (x(V) 0.99994) |
| TaV-11Pav.tdb | 588.7 | BCC_A2 (x(V) 0.10639) + C15_LAVES (x(V) 0.65095) + C14_LAVES (x(V) 0.66026) |
| TaV-13Bro.tdb | 631.44 | C15_LAVES (x(V) 0.66832) + C14_LAVES (x(V) 0.66932) + BCC_A2 (x(V) 0.99971) |
| TaV-13Bro.tdb | 605.4 | BCC_A2 (x(V) 0.15681) + C15_LAVES (x(V) 0.65261) + C14_LAVES (x(V) 0.6608) |

Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/TA/TA-V.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/TA/TA-V.json) · [CALPHAD hull TaV-04Dan-LB](https://data.orchid-project.org/hulls/calphad-sgte/TA/TA-V--TaV-04Dan-LB.json) · [CALPHAD hull TaV-04Dan-final](https://data.orchid-project.org/hulls/calphad-sgte/TA/TA-V--TaV-04Dan-final.json) · [CALPHAD hull TaV-11Pav-3sl](https://data.orchid-project.org/hulls/calphad-sgte/TA/TA-V--TaV-11Pav-3sl.json) · [CALPHAD hull TaV-11Pav](https://data.orchid-project.org/hulls/calphad-sgte/TA/TA-V--TaV-11Pav.json)

## Invariant reactions (literature)

Table: Invariant reactions reported in the literature for the Ta–V system (4)

| T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote |
|---:|---|---|---|---|---|---|
| 1553 | peritectoid: C14 + bcc \<-> C15 | C14: V 0.64; bcc: V 0.45; C15: V 0.63 | experimental | [1] Danon 2004; _cites Savitskii 1972_ | Table 3, p. 6, row 16; `ORC-IR5CIUOXWQ` |  |
| 1548 | peritectoid: C14 + bcc \<-> C15 | C14: V 0.64; bcc: V 0.496; C15: V 0.626 | model | [1] Danon 2004 | Table 3, p. 6, row 17; `ORC-XUQKKT6RM4` |  |
| 1400 | eutectoid: C14 \<-> C15 + bcc | C14: V 0.69; C15: V 0.687; bcc: V 0.936 | model | [1] Danon 2004 | Table 3, p. 6, row 19; `ORC-U7LRB7BN6G` |  |
| 1398 | eutectoid: C14 \<-> C15 + bcc | C14: V 0.71; C15: V 0.69; bcc: V 0.91 | experimental | [1] Danon 2004; _cites Savitskii 1972_ | Table 3, p. 6, row 18; `ORC-NOBTI6MRCP` |  |

## 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, Ta–V system (5)

| Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote |
|---|---|---:|---:|---|---:|---:|---|---|---|
| TaV2 | [TaV2](https://data.orchid-project.org/compounds/TaV2.html) | -11.7 kJ/mol-atom |  | model | -10.061 (mp-aaabghei) | -12.128 (oqmd-1365869) | [2] Broz 2013; _cites Charifi 2009_ | Table 2, p. 6, row 2; `ORC-P7UOZYKX5T.77c7a7` |  |
| TaV2 | [TaV2](https://data.orchid-project.org/compounds/TaV2.html) | -11.4 kJ/mol-atom | 0 | unspecified | -10.061 (mp-aaabghei) | -12.128 (oqmd-1365869) | [2] Broz 2013 | Table 2, p. 6, row 1; `ORC-43Q245UIWR.2de6a7` |  |
| TaV2 | [TaV2](https://data.orchid-project.org/compounds/TaV2.html) | -11.4 kJ/mol-atom | 0 | model | -10.061 (mp-aaabghei) | -12.128 (oqmd-1365869) | [2] Broz 2013; _cites Pavlu 2011_ [doi](https://doi.org/10.1016/j.calphad.2010.12.002) | Table 2, p. 6, row 3; `ORC-QGYXQE3PYW.872e43` |  |
| TaV2 | [TaV2](https://data.orchid-project.org/compounds/TaV2.html) | -10.2 kJ/mol-atom | 0 | model | -10.061 (mp-aaabghei) | -12.128 (oqmd-1365869) | [2] Broz 2013; _cites Pavlu 2011_ [doi](https://doi.org/10.1016/j.calphad.2010.12.002) | Table 2, p. 6, row 5; `ORC-C7ISSWAY6Y.4500ac` |  |
| TaV2 | [TaV2](https://data.orchid-project.org/compounds/TaV2.html) | -10.2 kJ/mol-atom | 0 | unspecified | -10.061 (mp-aaabghei) | -12.128 (oqmd-1365869) | [2] Broz 2013 | Table 2, p. 6, row 4; `ORC-CAW5LG4ZO4.fceaaa` |  |

## Other properties

### Phase transition (13)

Table: Phase transition, Ta–V system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Phase transition | 1565 K | 1565 | congruent transformation: bcc \<-> C15; _bcc: V 0.66; C15: V 0.66_ | model | [1] Danon 2004 | Table 3, p. 6, row 15; `ORC-IVE44OY3FH` |  |
| Phase transition | 1574 K | 1574 | congruent transformation: bcc \<-> C15; _bcc: V 0.667; C15: V 0.667_ | model | [1] Danon 2004; _cites Kaufman 1991_ [doi](https://doi.org/10.1016/0364-5916%2891%2990004-4) | Table 3, p. 6, row 14; `ORC-Y4JH6ATDKN` |  |
| Phase transition | 1583 K | 1583 | congruent transformation: bcc \<-> C15; _bcc: V 0.67; C15: V 0.67_ | experimental | [1] Danon 2004; _cites Nefedov 1965_ | Table 3, p. 6, row 13; `ORC-UUELXVBTD7` |  |
| Phase transition | 1593 K | 1593 | congruent transformation: bcc \<-> C15; _bcc: V 0.67; C15: V 0.67_ | experimental | [1] Danon 2004; _cites Carlson 1959_ | Table 3, p. 6, row 12; `ORC-3T7OUI2OHH` |  |
| Phase transition | 1693 K | 1693 | congruent transformation: bcc \<-> C14; _bcc: V 0.67_ | experimental | [1] Danon 2004; _cites Savitskii 1972_ | Table 3, p. 6, row 10; `ORC-7CZJG3NX5U` |  |
| Phase transition | 1693 K | 1693 | congruent transformation: bcc \<-> C14; _bcc: V 0.67_ | experimental | [1] Danon 2004; _cites Eremenko 1962_ | Table 3, p. 6, row 9; `ORC-TTTSQKX4W7` |  |
| Phase transition | 1702 K | 1702 | congruent transformation: bcc \<-> C14; _bcc: V 0.673_ | model | [1] Danon 2004 | Table 3, p. 6, row 11; `ORC-DSCATBNH2L` |  |
| Phase transition | 2093 K | 2093 | other: Liquid \<-> bcc; _Liquid: V 0.892; bcc: V 0.892_ | experimental | [1] Danon 2004; _cites Carlson 1959_ | Table 3, p. 6, row 4; `ORC-BLMXTVKXXK` |  |
| Phase transition | 2098 K | 2098 | other: Liquid \<-> bcc; _Liquid: V 0.85; bcc: V 0.85_ | experimental | [1] Danon 2004; _cites Nefedov 1965_ | Table 3, p. 6, row 3; `ORC-HTH2ML4Z7L` |  |
| Phase transition | 2099 K | 2099 | other: Liquid \<-> bcc; _Liquid: V 0.871; bcc: V 0.871_ | model | [1] Danon 2004 | Table 3, p. 6, row 5; `ORC-U4LJDCUTUN.0b802f` |  |
| Phase transition | 2114 K | 2114 | other: Liquid \<-> bcc; _Liquid: V 0.875; bcc: V 0.875_ | model | [1] Danon 2004 | Table 3, p. 6, row 6; `ORC-BABHC3TFRK` |  |
| Phase transition | 2153 K | 2153 | other: Liquid \<-> bcc; _Liquid: V 0.89; bcc: V 0.89_ | experimental | [1] Danon 2004; _cites Smith 1983_ [doi](https://doi.org/10.1007/bf02868668) | Table 3, p. 6, row 2; `ORC-KOEZYEJIXU` |  |
| Phase transition | 2182.3 K | 2182.3 | other: Liquid \<-> bcc; _Liquid: V 0.9735; bcc: V 0.9735_ | model | [1] Danon 2004; _cites Smith 1983_ [doi](https://doi.org/10.1007/bf02868668) | Table 3, p. 6, row 1; `ORC-UO6QO6DCRR` |  |

### Mixing / partial (1)

Table: Mixing / partial, Ta–V system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Enthalpy of mixing; _printed: enthalpy of mixing_ | -1 kJ/mol-atom | 3373 | liquid | model | [1] Danon 2004 | p. 4; `ORC-VQETMHFONO` | “In addition, an enthalpy of mixing of the liquid of -1000 J/mol of atoms at 3373 K was fixed as input for the equiatomic alloy, using liquid Ta and V at the same temperature as reference states.” |

### Crystal structure (105)

Table: Crystal structure, Ta–V system

| Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote |
|---|---:|---:|---|---|---|---|---|
| Lattice a | 5.3847 Å | 0 | C14; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 8; `ORC-5RVANNAEIU.141164` |  |
| Lattice a | 5.0648 Å | 0 | C14; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 5; `ORC-JEQXNJPUCL.7514d4` |  |
| Lattice a | 5.4068 Å | 0 | C14; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 7; `ORC-QWXB6B2NRT.e1071c` |  |
| Lattice a | 5.4352 Å | 0 | C14; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 10; `ORC-T5UJIPECGX.615e33` |  |
| Lattice a | 5.4507 Å | 0 | C14; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 11; `ORC-WGB2FKPIZE.bd67e5` |  |
| Lattice a | 7.5399 Å | 0 | C15; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 9; `ORC-BFSOT3RUG6.5d2eda` |  |
| Lattice a | 7.6451 Å | 0 | C15; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 12; `ORC-BR4ONBOIMA.7c49cd` |  |
| Lattice a | 7.0957 Å | 0 | C15; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 6; `ORC-KC2ZTPPDQ2.b54d89` |  |
| Lattice a | 5.0542 Å | 0 | C36; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 14; `ORC-2KAPXKAKXJ.c08312` |  |
| Lattice a | 5.4416 Å | 0 | C36; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 18; `ORC-7QE55JJ5LM.77f1b7` |  |
| Lattice a | 5.4245 Å | 0 | C36; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 15; `ORC-W6LD2ZXVEG.633244` |  |
| Lattice a | 5.3818 Å | 0 | C36; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 16; `ORC-YCK3G67FYN.086723` |  |
| Lattice a | 5.4406 Å | 0 | C36; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 17; `ORC-ZJZZ7ZX2DP.c43123` |  |
| Lattice a | 3.309 Å | 0 | NM BCC Ta; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 1, p. 3, row 4; `ORC-6G373AZMAP.0ab91e` |  |
| Lattice a | 7.167 Å | 0 | TaV2; _alloy: Ta 0.333333, V 0.666667_ | DFT | [2] Broz 2013 | Table 1, p. 3, row 30; `ORC-2KPERNABHT` |  |
| Lattice a | 5.092 Å | 0 | TaV2; _alloy: Ta 0.333333, V 0.666667_ | DFT | [2] Broz 2013 | Table 1, p. 3, row 26; `ORC-6QUFMAASTV.6fb45b` |  |
| Lattice a | 5.09 Å | 298.15 | C14 | experimental | [1] Danon 2004; _cites Nefedov 1965_ | Table 2, p. 3, row 9; `ORC-2T6RDTCEBI.9a0756` |  |
| Lattice a | 4.96 Å | 298.15 | C14; _alloy: V 0.666667_ | experimental | [3] Pavlů 2011; _cites Villars 1991_ | Table 2, p. 3, row 1; `ORC-5DT4SDXKK6.d2b65e` |  |
| Lattice a | 5.058 Å | 298.15 | C14; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Nefedov 1965_ | Table 2, p. 3, row 2; `ORC-6IMO6AWYT5.0d799a` |  |
| Lattice a | 4.96 Å | 298.15 | C14; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Savitskii 1972_ | Table 2, p. 3, row 11; `ORC-HQYAFSNC2R.d8d454` |  |
| Lattice a | 4.96 Å | 298.15 | C14; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Yu 1965_ | Table 2, p. 3, row 10; `ORC-IR234SS3UH.98e91a` |  |
| Lattice a | 5.058 Å | 298.15 | C14 | experimental | [1] Danon 2004; _cites Nefedov 1965_ | Table 2, p. 3, row 8; `ORC-T3CMPOOJOI.cd3f40` |  |
| Lattice a | 7.163 Å | 298.15 | C15; _alloy: V 0.68_ | experimental | [1] Danon 2004; _cites Carlson 1959_ | Table 2, p. 3, row 3; `ORC-32UIORKGTO` |  |
| Lattice a | 7.1555 Å | 298.15 | C15; _alloy: V 0.666667_ | experimental | [3] Pavlů 2011; _cites Villars 1991_ | Table 2, p. 3, row 2; `ORC-6P24PCYBR7.a72983` |  |
| Lattice a | 7.155 Å | 298.15 | C15; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Wennerstrom 1975_ [doi](https://doi.org/10.1088/0031-8949/11/6/008) | Table 2, p. 3, row 6; `ORC-6P7ECKBSJY` |  |
| Lattice a | 7.14 Å | 298.15 | C15; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Pushin 1980_ | Table 2, p. 3, row 4; `ORC-BLF3Z6Y6BT` |  |
| Lattice a | 7.153 Å | 298.15 | C15; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Schippnick 1974_ [doi](https://doi.org/10.1016/0038-1098%2874%2991202-2) | Table 2, p. 3, row 5; `ORC-DGUIEGWOSC` |  |
| Lattice a | 7.1597 Å | 298.15 | C15; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Lynch 1981_ [doi](https://doi.org/10.1016/0022-3697%2881%2990050-0) | Table 2, p. 3, row 1; `ORC-GF26D473UZ` |  |
| Lattice a | 7.16 Å | 298.15 | C15; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Somenkov 1966_ | Table 2, p. 3, row 7; `ORC-SIDJCYUVTP` |  |
| Lattice a | 7.14 Å | 298.15 | C15; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Yu 1965_ | Table 2, p. 3, row 12; `ORC-SYYGCON3I4` |  |
| Lattice a | 3.3019 Å | 298.15 | NM BCC Ta; _alloy: V 0_ | experimental | [3] Pavlů 2011; _cites Villars 1991_ | Table 1, p. 3, row 3; `ORC-Y7DR2UPMVT.35bd67` |  |
| Lattice a | 7.157 Å | 298.15 | TaV2; _alloy: Ta 0.333333, V 0.666667_ | unspecified | [2] Broz 2013; _cites Smith 1983_ [doi](https://doi.org/10.1007/bf02868668) | Table 1, p. 3, row 29; `ORC-XZEU46V3ZD` |  |
| Lattice a | 5.058 Å ± 0.005 | 300 | TaV2; _alloy: Ta 0.333333, V 0.666667_ | model | [2] Broz 2013; _cites Nefedov 2013_ | Table 1, p. 3, row 25; `ORC-P56DPNMCZ2.adb10f` |  |
| Lattice c | 8.505 Å | 0 | C14; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 8; `ORC-5RVANNAEIU.1e1fc0` |  |
| Lattice c | 8.0425 Å | 0 | C14; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 5; `ORC-JEQXNJPUCL.d4c083` |  |
| Lattice c | 7.9277 Å | 0 | C14; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 7; `ORC-QWXB6B2NRT.7edaaf` |  |
| Lattice c | 8.3071 Å | 0 | C14; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 10; `ORC-T5UJIPECGX.23b7ba` |  |
| Lattice c | 8.6784 Å | 0 | C14; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 11; `ORC-WGB2FKPIZE.64d302` |  |
| Lattice c | 16.1519 Å | 0 | C36; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 14; `ORC-2KAPXKAKXJ.37f2f5` |  |
| Lattice c | 17.4252 Å | 0 | C36; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 18; `ORC-7QE55JJ5LM.7029d8` |  |
| Lattice c | 15.7626 Å | 0 | C36; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 15; `ORC-W6LD2ZXVEG.3ef5fc` |  |
| Lattice c | 17.0652 Å | 0 | C36; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 16; `ORC-YCK3G67FYN.e4a001` |  |
| Lattice c | 16.58 Å | 0 | C36; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 17; `ORC-ZJZZ7ZX2DP.8c0c91` |  |
| Lattice c | 8.069 Å | 0 | TaV2; _alloy: Ta 0.333333, V 0.666667_ | DFT | [2] Broz 2013 | Table 1, p. 3, row 26; `ORC-6QUFMAASTV.7ba8a5` |  |
| Lattice c | 8.322 Å | 298.15 | C14 | experimental | [1] Danon 2004; _cites Nefedov 1965_ | Table 2, p. 3, row 9; `ORC-2T6RDTCEBI.5d7162` |  |
| Lattice c | 8.11 Å | 298.15 | C14; _alloy: V 0.666667_ | experimental | [3] Pavlů 2011; _cites Villars 1991_ | Table 2, p. 3, row 1; `ORC-5DT4SDXKK6.58c40d` |  |
| Lattice c | 8.25 Å | 298.15 | C14; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Nefedov 1965_ | Table 2, p. 3, row 2; `ORC-6IMO6AWYT5.324351` |  |
| Lattice c | 8.11 Å | 298.15 | C14; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Savitskii 1972_ | Table 2, p. 3, row 11; `ORC-HQYAFSNC2R.0bab6e` |  |
| Lattice c | 8.11 Å | 298.15 | C14; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Yu 1965_ | Table 2, p. 3, row 10; `ORC-IR234SS3UH.215a04` |  |
| Lattice c | 8.25 Å | 298.15 | C14 | experimental | [1] Danon 2004; _cites Nefedov 1965_ | Table 2, p. 3, row 8; `ORC-T3CMPOOJOI.96207d` |  |
| Lattice c | 8.25 Å ± 0.005 | 300 | TaV2; _alloy: Ta 0.333333, V 0.666667_ | model | [2] Broz 2013; _cites Nefedov 2013_ | Table 1, p. 3, row 25; `ORC-P56DPNMCZ2.82bb43` |  |
| lattice c a | 1 not_printed | 0 | NM BCC Ta; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 1, p. 3, row 4; `ORC-6G373AZMAP.cdb02f` |  |
| lattice c a | 1.635 not_printed | 298.15 | C14 | experimental | [1] Danon 2004; _cites Nefedov 1965_ | Table 2, p. 3, row 9; `ORC-2T6RDTCEBI.3682a7` |  |
| lattice c a | 1.631 not_printed | 298.15 | C14; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Nefedov 1965_ | Table 2, p. 3, row 2; `ORC-6IMO6AWYT5.8e4c46` |  |
| lattice c a | 1.63 not_printed | 298.15 | C14; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Savitskii 1972_ | Table 2, p. 3, row 11; `ORC-HQYAFSNC2R.6d711c` |  |
| lattice c a | 1.63 not_printed | 298.15 | C14; _alloy: V 0.666667_ | experimental | [1] Danon 2004; _cites Yu 1965_ | Table 2, p. 3, row 10; `ORC-IR234SS3UH.e62892` |  |
| lattice c a | 1.631 not_printed | 298.15 | C14 | experimental | [1] Danon 2004; _cites Nefedov 1965_ | Table 2, p. 3, row 8; `ORC-T3CMPOOJOI.1baad8` |  |
| lattice c a | 1 not_printed | 298.15 | NM BCC Ta; _alloy: V 0_ | experimental | [3] Pavlů 2011; _cites Villars 1991_ | Table 1, p. 3, row 3; `ORC-Y7DR2UPMVT.8d7d63` |  |
| lattice v atom | 1.78 10^7 pm^3 | 0 | C14; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 8; `ORC-5RVANNAEIU.9ca3fc` |  |
| lattice v atom | 1.489 10^7 pm^3 | 0 | C14; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 5; `ORC-JEQXNJPUCL.087178` |  |
| lattice v atom | 1.673 10^7 pm^3 | 0 | C14; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 7; `ORC-QWXB6B2NRT.8b2b44` |  |
| lattice v atom | 1.771 10^7 pm^3 | 0 | C14; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 10; `ORC-T5UJIPECGX.6345d5` |  |
| lattice v atom | 1.861 10^7 pm^3 | 0 | C14; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 11; `ORC-WGB2FKPIZE.be4f69` |  |
| lattice v atom | 1.786 10^7 pm^3 | 0 | C15; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 9; `ORC-BFSOT3RUG6.d3045c` |  |
| lattice v atom | 1.862 10^7 pm^3 | 0 | C15; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 12; `ORC-BR4ONBOIMA.6c8604` |  |
| lattice v atom | 1.489 10^7 pm^3 | 0 | C15; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 6; `ORC-KC2ZTPPDQ2.8933c9` |  |
| lattice v atom | 1.489 10^7 pm^3 | 0 | C36; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 14; `ORC-2KAPXKAKXJ.9b60b0` |  |
| lattice v atom | 1.862 10^7 pm^3 | 0 | C36; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 18; `ORC-7QE55JJ5LM.60ab79` |  |
| lattice v atom | 1.674 10^7 pm^3 | 0 | C36; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 15; `ORC-W6LD2ZXVEG.05a794` |  |
| lattice v atom | 1.784 10^7 pm^3 | 0 | C36; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 16; `ORC-YCK3G67FYN.e74312` |  |
| lattice v atom | 1.771 10^7 pm^3 | 0 | C36; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 17; `ORC-ZJZZ7ZX2DP.41003b` |  |
| lattice v atom | 1.812 10^7 pm^3 | 0 | NM BCC Ta; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 1, p. 3, row 4; `ORC-6G373AZMAP.0a85a6` |  |
| lattice v atom | 1.44 10^7 pm^3 | 298.15 | C14; _alloy: V 0.666667_ | experimental | [3] Pavlů 2011; _cites Villars 1991_ | Table 2, p. 3, row 1; `ORC-5DT4SDXKK6.448579` |  |
| lattice v atom | 1.527 10^7 pm^3 | 298.15 | C15; _alloy: V 0.666667_ | experimental | [3] Pavlů 2011; _cites Villars 1991_ | Table 2, p. 3, row 2; `ORC-6P24PCYBR7.18c079` |  |
| lattice v atom | 1.8 10^7 pm^3 | 298.15 | NM BCC Ta; _alloy: V 0_ | experimental | [3] Pavlů 2011; _cites Villars 1991_ | Table 1, p. 3, row 3; `ORC-Y7DR2UPMVT.63df89` |  |
| site fractional coordinates |  | 0 | C14; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 8; `ORC-5RVANNAEIU.4bf150` |  |
| site fractional coordinates |  | 0 | C14; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 8; `ORC-5RVANNAEIU.ff84e8` |  |
| site fractional coordinates |  | 0 | C14; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 5; `ORC-JEQXNJPUCL.8a097c` |  |
| site fractional coordinates |  | 0 | C14; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 5; `ORC-JEQXNJPUCL.f9ab84` |  |
| site fractional coordinates |  | 0 | C14; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 7; `ORC-QWXB6B2NRT.5e859f` |  |
| site fractional coordinates |  | 0 | C14; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 7; `ORC-QWXB6B2NRT.5fb1e0` |  |
| site fractional coordinates |  | 0 | C14; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 10; `ORC-T5UJIPECGX.0b5b79` |  |
| site fractional coordinates |  | 0 | C14; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 10; `ORC-T5UJIPECGX.51c93d` |  |
| site fractional coordinates |  | 0 | C14; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 11; `ORC-WGB2FKPIZE.37bdbd` |  |
| site fractional coordinates |  | 0 | C14; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 11; `ORC-WGB2FKPIZE.efad52` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 14; `ORC-2KAPXKAKXJ.115f7a` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 14; `ORC-2KAPXKAKXJ.80ea25` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 14; `ORC-2KAPXKAKXJ.b4bf5b` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.666667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 14; `ORC-2KAPXKAKXJ.d5adfb` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 18; `ORC-7QE55JJ5LM.1cd86f` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 18; `ORC-7QE55JJ5LM.7a57d0` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 18; `ORC-7QE55JJ5LM.9fbdf9` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 18; `ORC-7QE55JJ5LM.cdfc8f` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 15; `ORC-W6LD2ZXVEG.14415c` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 15; `ORC-W6LD2ZXVEG.81b13a` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 15; `ORC-W6LD2ZXVEG.89615a` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.5_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 15; `ORC-W6LD2ZXVEG.dd10fd` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 16; `ORC-YCK3G67FYN.0fd7ba` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 16; `ORC-YCK3G67FYN.33e884` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 16; `ORC-YCK3G67FYN.4c666c` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.333333_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 16; `ORC-YCK3G67FYN.909cb7` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 17; `ORC-ZJZZ7ZX2DP.1129c7` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 17; `ORC-ZJZZ7ZX2DP.48577b` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 17; `ORC-ZJZZ7ZX2DP.79d75f` |  |
| site fractional coordinates |  | 0 | C36; _alloy: V 0.166667_ | DFT | [3] Pavlů 2011 | Table 2, p. 3, row 17; `ORC-ZJZZ7ZX2DP.ae13b6` |  |

## Sources

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

1. C.A Danon, C Servant, A thermodynamic evaluation of the Ta–V system, Journal of Alloys and Compounds 366, 191-200 (2004). [doi:10.1016/s0925-8388(03)00728-x](https://doi.org/10.1016/s0925-8388%2803%2900728-x)
2. P. Broz, A.U. Khan, H. Niu, X.-Q. Chen, D. Li, J. Vrestal et al., The system Ta–V–Si: Thermodynamic modeling, Journal of Solid State Chemistry 199, 171-180 (2013). [doi:10.1016/j.jssc.2012.12.003](https://doi.org/10.1016/j.jssc.2012.12.003)
3. J. Pavlů, J. Vřešt’ál, X.-Q. Chen, P. Rogl, Thermodynamic modeling of Laves phases in the Ta–V system: Reassessment using first-principles results, Calphad 35, 103-108 (2011). [doi:10.1016/j.calphad.2010.12.002](https://doi.org/10.1016/j.calphad.2010.12.002)

## 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/).