N–Ta phases

6 phases (tier A 2, liquid 1, gas 1, needs_review 1, interstitial_fcc_a1_compound 1); 6 stable in a calculated diagram. Structure types are assigned only when the stored evidence supports an assignment under the stated tier rules (tier A: standard phase name; tier B: unique Materials Project + OQMD on-hull match, DFT-supported; tier C: one structure stated by the assessment's crystallographic table, assessor-stated); other phases list candidates and are marked needs_review. Stability is from phase diagrams calculated with pycalphad from the SGTE binary collection (evidence class: model).

Data: interactive registry · full JSON · N–Ta system page · Markdown · field reference

Phases of the N–Ta system (6)
Phase	Structure	Basis	Stability (calculated)	TDB models
BCC_A2 phase:n-ta:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–3999.96 K, x(N) 0–0.10705	1
FCC_A1 phase:n-ta:fcc-a1	NaCl · B1 · cF8 · Fm-3m (225)	assigned	stable in 1 of 1 calculated diagram(s): 1966.92–2281.07 K, x(N) 0.41782–0.44066	1
HCP_A3 phase:n-ta:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–2993.7 K, x(N) 0.2347–0.33333	1
LIQUID phase:n-ta:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 2591.13–4000 K, x(N) 0–0.2384	1
N2GAS phase:n-ta:n2gas	gas	gas	stable in 1 of 1 calculated diagram(s): 300–4000 K, x(N) 1–1	1
TAN_EPS phase:n-ta:tan-eps		needs_review	stable in 1 of 1 calculated diagram(s): 300–2079.56 K, x(N) 0.5–0.5	1

BCC_A2 (N–Ta)

Id: phase:n-ta:bcc-a2; status assigned
Structure: W · A2 · cI2 · Im-3m (229); type st:a2-w-ci2; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–3999.96 K, x(N) 0–0.10705
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:n-ta:bcc-a2
tdb: tdb:TaN-98Fri-LB.tdb:BCC_A2

TDB models of BCC_A2 (1): PHASE and CONSTITUENT statements as written

TaN-98Fri-LB.tdb: BCC_A2, type code %B, sha256 1ccb77038a7bdc04…

36: PHASE BCC_A2 %B 2 1 3 !
37: CONST BCC_A2 : TA : N VA% : !

Example references (1 of 1; assessments first):

doi:10.1016/S0925-8388(98)00582-9 K. Frisk, J. Alloys Compd., 278, 216-26(1998).
assessment that models this phase

FCC_A1 (N–Ta)

Id: phase:n-ta:fcc-a1; status assigned
Structure: NaCl · B1 · cF8 · Fm-3m (225); type st:b1-nacl-cf8; interstitial_fcc_a1_compound; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1966.92–2281.07 K, x(N) 0.41782–0.44066
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:n-ta:fcc-a1
tdb: tdb:TaN-98Fri-LB.tdb:FCC_A1

TDB models of FCC_A1 (1): PHASE and CONSTITUENT statements as written

TaN-98Fri-LB.tdb: FCC_A1, type code %A, sha256 1ccb77038a7bdc04…

31: PHASE FCC_A1 %A 2 1 1 !
32: CONST FCC_A1 : TA : N VA% : !

Example references (1 of 1; assessments first):

doi:10.1016/S0925-8388(98)00582-9 K. Frisk, J. Alloys Compd., 278, 216-26(1998).
assessment that models this phase

HCP_A3 (N–Ta)

Id: phase:n-ta:hcp-a3; status assigned
Structure: Mg · A3 · hP2 · P6_3/mmc (194); type st:a3-mg-hp2; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–2993.7 K, x(N) 0.2347–0.33333
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:n-ta:hcp-a3
tdb: tdb:TaN-98Fri-LB.tdb:HCP_A3

TDB models of HCP_A3 (1): PHASE and CONSTITUENT statements as written

TaN-98Fri-LB.tdb: HCP_A3, type code %A, sha256 1ccb77038a7bdc04…

41: PHASE HCP_A3 %A 2 1 0.5 !
42: CONST HCP_A3 : TA : N VA% : !

Example references (1 of 1; assessments first):

doi:10.1016/S0925-8388(98)00582-9 K. Frisk, J. Alloys Compd., 278, 216-26(1998).
assessment that models this phase

LIQUID (N–Ta)

Id: phase:n-ta:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 2591.13–4000 K, x(N) 0–0.2384
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:n-ta:liquid
tdb: tdb:TaN-98Fri-LB.tdb:LIQUID

TDB models of LIQUID (1): PHASE and CONSTITUENT statements as written

TaN-98Fri-LB.tdb: LIQUID, type code %, sha256 1ccb77038a7bdc04…

26: PHASE LIQUID:L % 1 1 !
27: CONST LIQUID:L : N TA : !

Example references (1 of 1; assessments first):

doi:10.1016/S0925-8388(98)00582-9 K. Frisk, J. Alloys Compd., 278, 216-26(1998).
assessment that models this phase

N2GAS (N–Ta)

Id: phase:n-ta:n2gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–4000 K, x(N) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:n-ta:n2gas
tdb: tdb:TaN-98Fri-LB.tdb:N2GAS

TDB models of N2GAS (1): PHASE and CONSTITUENT statements as written

TaN-98Fri-LB.tdb: N2GAS, type code %, sha256 1ccb77038a7bdc04…

49: PHASE N2GAS % 1 1 !
50: CONST N2GAS : N2 : !

Example references (1 of 1; assessments first):

doi:10.1016/S0925-8388(98)00582-9 K. Frisk, J. Alloys Compd., 278, 216-26(1998).
assessment that models this phase

TAN_EPS (N–Ta)

Id: phase:n-ta:tan-eps; status needs_review
No structure assigned. Why: name_has_descriptive_tokens:EPS; no_structure_token
Candidate (dft_mp): P-62m (189) — on-hull MP TaN at x(TA)=0.5000
Candidate (dft_oqmd): P-62m (189) — on-hull OQMD N1 Ta1 at x(TA)=0.5000
Candidate (sgte_mmc2): TaN-eps · hP6 · P-62m (189) — Hallstedt 2025 mmc2 row for TAN_EPS: TaN-epsilon (LT)
Candidate (tdb_comment): TaN · hP6 · P-62m — TaN-98Fri-LB.tdb: 'Prototype TaN (hP6, P-62m)'
Stoichiometry: N 0.5000, Ta 0.5000
Stability: stable in 1 of 1 calculated diagram(s): 300–2079.56 K, x(N) 0.5–0.5
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:n-ta:tan-eps
tdb: tdb:TaN-98Fri-LB.tdb:TAN_EPS

TDB models of TAN_EPS (1): PHASE and CONSTITUENT statements as written

TaN-98Fri-LB.tdb: TAN_EPS, type code %, sha256 1ccb77038a7bdc04…

46: PHASE TAN_EPS % 2 1 1 !
47: CONST TAN_EPS : TA : N : !

Example references (1 of 1; assessments first):

doi:10.1016/S0925-8388(98)00582-9 K. Frisk, J. Alloys Compd., 278, 216-26(1998).
assessment that models this phase

Please cite

R. Arróyave, J. Saal, D. Shin, ORCHID-Registry: phase registry of binary systems (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735970
R. Arróyave, J. Saal, D. Shin, ORCHID data: umbrella record of the ORCHID datasets (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23736065

Also cite 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); the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work). 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.

@misc{orchid_phase_registry_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Registry: phase registry of binary systems}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735970},
  url       = {https://doi.org/10.5281/zenodo.23735970},
  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}
}