Ni–Se phases

10 phases (tier A 7, tier C 1, liquid 1, needs_review 1); 8 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 · Ni–Se system page · Markdown · field reference

Phases of the Ni–Se system (10)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
HEXAGONAL_A8 phase:ni-se:a8-hexagonal	gamma-Se · A8 · hP3 · P3_121 (152)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–497.13 K, x(Se) 1–1	3	1
BCC_A2 phase:ni-se:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	not stable in 1 calculated diagram(s)	0	1
FCC_A1 phase:ni-se:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1741.24 K, x(Se) 0–0	6	1
HCP_A3 phase:ni-se:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 1 calculated diagram(s)	0	1
LIQUID phase:ni-se:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 490.13–2500 K, x(Se) 0–1	18	1
NI3SE2_HT phase:ni-se:ni3se2		needs_review	stable in 1 of 1 calculated diagram(s): 839.29–1057.48 K, x(Se) 0.405–0.405	14	1
NI3SE2_D5E phase:ni-se:ni3se2-d5e	Ni3S2 · D5_e · hR5 · R32 (155)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–865.64 K, x(Se) 0.4–0.4	8	1
NI6SE5 phase:ni-se:ni6se5	Ni6Se5 · oP88 · Pca2_1 (29)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 672.72–920.29 K, x(Se) 0.45455–0.45455	8	1
NISE_B81 phase:ni-se:nise-b81	NiAs · B8_1 · hP4 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1231.3 K, x(Se) 0.50889–0.57024	19	1
NISE2_C2 phase:ni-se:nise2-c2	beta-FeS2 · C2 · cP12 · Pa-3 (205)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1131.01 K, x(Se) 0.66667–0.66667	9	1

HEXAGONAL_A8 (Ni–Se)

Id: phase:ni-se:a8-hexagonal; status assigned
Structure: gamma-Se · A8 · hP3 · P3_121 (152); type st:a8-gamma-se-hp3; tier A: standard phase name; confidence high
Stoichiometry: Se 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–497.13 K, x(Se) 1–1
Literature: 3 values (3 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:ni-se:a8-hexagonal, corpus:phase:ni-se:hexagonal-a8
paper: paper:10.1007/s11669-021-00906-9:hex_A8 (Se)
tdb: tdb:NiSe-21Zob.tdb:HEXAGONAL_A8

TDB models of HEXAGONAL_A8 (1): PHASE and CONSTITUENT statements as written

NiSe-21Zob.tdb: HEXAGONAL_A8, type code %, sha256 1b075f9b26619344…

50: PHASE HEXAGONAL_A8 % 1 1 !
51: CONST HEXAGONAL_A8 : SE : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-021-00906-9 Ondřej Zobač, Kateřina Buchlovská, Jana Pavlů, Aleš Kroupa, Thermodynamic Description of Binary System Nickel-Selenium, J. Phase Equilib. Diffus. 42, 468-478 (2021).
assessment that models this phase; reports values for this phase
doi:10.1007/bf00905165 K. L. Komarek, K. Wessely, Die Systeme Nickel?Selen und Kobalt?Nickel-Selen, Monatshefte fr Chemie 103, 923-933 (1972).
cited as the source of values for this phase

BCC_A2 (Ni–Se)

Id: phase:ni-se:bcc-a2; status assigned
Structure: W · A2 · cI2 · Im-3m (229); type st:a2-w-ci2; tier A: standard phase name; confidence high
Stoichiometry: Ni 1.0000
Stability: not stable in 1 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ni-se:bcc-a2
tdb: tdb:NiSe-21Zob.tdb:BCC_A2

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

NiSe-21Zob.tdb: BCC_A2, type code %B, sha256 1b075f9b26619344…

40: PHASE BCC_A2 %B 2 1 3 !
41: CONST BCC_A2 : NI : VA : !

Example references (1 of 1; assessments first):

doi:10.1007/s11669-021-00906-9 Ondřej Zobač, Kateřina Buchlovská, Jana Pavlů, Aleš Kroupa, Thermodynamic Description of Binary System Nickel-Selenium, J. Phase Equilib. Diffus. 42, 468-478 (2021).
assessment that models this phase

FCC_A1 (Ni–Se)

Id: phase:ni-se:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
Stoichiometry: Ni 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–1741.24 K, x(Se) 0–0
Literature: 6 values (6 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:ni-se:fcc-a1
paper: paper:10.1007/s11669-021-00906-9:FCC_A1
tdb: tdb:NiSe-21Zob.tdb:FCC_A1

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

NiSe-21Zob.tdb: FCC_A1, type code %A, sha256 1b075f9b26619344…

35: PHASE FCC_A1 %A 2 1 1 !
36: CONST FCC_A1 : NI : VA : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-021-00906-9 Ondřej Zobač, Kateřina Buchlovská, Jana Pavlů, Aleš Kroupa, Thermodynamic Description of Binary System Nickel-Selenium, J. Phase Equilib. Diffus. 42, 468-478 (2021).
assessment that models this phase; reports values for this phase
doi:10.1007/bf00905165 K. L. Komarek, K. Wessely, Die Systeme Nickel?Selen und Kobalt?Nickel-Selen, Monatshefte fr Chemie 103, 923-933 (1972).
cited as the source of values for this phase

HCP_A3 (Ni–Se)

Id: phase:ni-se:hcp-a3; status assigned
Structure: Mg · A3 · hP2 · P6_3/mmc (194); type st:a3-mg-hp2; tier A: standard phase name; confidence high
Stoichiometry: Ni 1.0000
Stability: not stable in 1 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ni-se:hcp-a3
tdb: tdb:NiSe-21Zob.tdb:HCP_A3

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

NiSe-21Zob.tdb: HCP_A3, type code %A, sha256 1b075f9b26619344…

45: PHASE HCP_A3 %A 2 1 0.5 !
46: CONST HCP_A3 : NI : VA : !

Example references (1 of 1; assessments first):

doi:10.1007/s11669-021-00906-9 Ondřej Zobač, Kateřina Buchlovská, Jana Pavlů, Aleš Kroupa, Thermodynamic Description of Binary System Nickel-Selenium, J. Phase Equilib. Diffus. 42, 468-478 (2021).
assessment that models this phase

LIQUID (Ni–Se)

Id: phase:ni-se:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 490.13–2500 K, x(Se) 0–1
Literature: 18 values (18 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:ni-se:liquid
paper: paper:10.1007/s11669-021-00906-9:Liquid, paper:10.1007/s11669-021-00906-9:Liquid’
tdb: tdb:NiSe-21Zob.tdb:LIQUID

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

NiSe-21Zob.tdb: LIQUID, type code %, sha256 1b075f9b26619344…

30: PHASE LIQUID:L % 1 1 !
31: CONST LIQUID:L : NI NISE SE : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-021-00906-9 Ondřej Zobač, Kateřina Buchlovská, Jana Pavlů, Aleš Kroupa, Thermodynamic Description of Binary System Nickel-Selenium, J. Phase Equilib. Diffus. 42, 468-478 (2021).
assessment that models this phase; reports values for this phase
doi:10.1007/bf00905165 K. L. Komarek, K. Wessely, Die Systeme Nickel?Selen und Kobalt?Nickel-Selen, Monatshefte fr Chemie 103, 923-933 (1972).
cited as the source of values for this phase

NI3SE2_HT (Ni–Se)

Id: phase:ni-se:ni3se2; status needs_review
No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
Candidate (literature_printed): (Ni3Se2-ht) · cF* — printed with a label mapped to this phase
Candidate (sgte_mmc2): (Ni3Se2-ht) — Hallstedt 2025 mmc2 row for NI3SE2_HT: Ni3Se2 (high T)
Stoichiometry: Ni 0.5950, Se 0.4050
Stability: stable in 1 of 1 calculated diagram(s): 839.29–1057.48 K, x(Se) 0.405–0.405
Literature: 14 values (14 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:ni-se:ni3se2, corpus:phase:ni-se:ni3se2-ht
paper: paper:10.1007/s11669-021-00906-9:Ni3Se2_HT
tdb: tdb:NiSe-21Zob.tdb:NI3SE2_HT

TDB models of NI3SE2_HT (1): PHASE and CONSTITUENT statements as written

NiSe-21Zob.tdb: NI3SE2_HT, type code %, sha256 1b075f9b26619344…

60: PHASE NI3SE2_HT % 2 0.595 0.405 !
61: CONST NI3SE2_HT : NI : SE : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-021-00906-9 Ondřej Zobač, Kateřina Buchlovská, Jana Pavlů, Aleš Kroupa, Thermodynamic Description of Binary System Nickel-Selenium, J. Phase Equilib. Diffus. 42, 468-478 (2021).
assessment that models this phase; reports values for this phase
doi:10.1007/bf00905165 K. L. Komarek, K. Wessely, Die Systeme Nickel?Selen und Kobalt?Nickel-Selen, Monatshefte fr Chemie 103, 923-933 (1972).
cited as the source of values for this phase

NI3SE2_D5E (Ni–Se)

Id: phase:ni-se:ni3se2-d5e; status assigned
Structure: Ni3S2 · D5_e · hR5 · R32 (155); type st:d5-e-ni3s2-hr5; tier A: standard phase name; confidence high
Caveat: DFT agrees: on-hull mp-aaaaadbc and oqmd-5233, space group 155
Stoichiometry: Ni 0.6000, Se 0.4000
Stability: stable in 1 of 1 calculated diagram(s): 300–865.64 K, x(Se) 0.4–0.4
Literature: 8 values (8 accepted) from 1 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:ni-se:ni3se2-d5e
mp: mp:mp-aaaaadbc
oqmd: oqmd:oqmd-5233
paper: paper:10.1007/s11669-021-00906-9:Ni3Se2_LT
tdb: tdb:NiSe-21Zob.tdb:NI3SE2_D5E

TDB models of NI3SE2_D5E (1): PHASE and CONSTITUENT statements as written

NiSe-21Zob.tdb: NI3SE2_D5E, type code %, sha256 1b075f9b26619344…

55: PHASE NI3SE2_D5E % 2 3 2 !
56: CONST NI3SE2_D5E : NI : SE : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-021-00906-9 Ondřej Zobač, Kateřina Buchlovská, Jana Pavlů, Aleš Kroupa, Thermodynamic Description of Binary System Nickel-Selenium, J. Phase Equilib. Diffus. 42, 468-478 (2021).
assessment that models this phase; reports values for this phase
doi:10.1007/bf00905165 K. L. Komarek, K. Wessely, Die Systeme Nickel?Selen und Kobalt?Nickel-Selen, Monatshefte fr Chemie 103, 923-933 (1972).
cited as the source of values for this phase

NI6SE5 (Ni–Se)

Id: phase:ni-se:ni6se5; status assigned
Structure: Ni6Se5 · oP88 · Pca2_1 (29); type st:ni6se5-op88; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated
Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) doi:10.1016/j.calphad.2025.102833
Caveat: not certain from the name or DFT alone (no_on_hull_entry_in_both, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
Stoichiometry: Ni 0.5455, Se 0.4545
Stability: stable in 1 of 1 calculated diagram(s): 672.72–920.29 K, x(Se) 0.45455–0.45455
Literature: 8 values (8 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:ni-se:ni6se5
paper: paper:10.1007/s11669-021-00906-9:Ni6Se5
tdb: tdb:NiSe-21Zob.tdb:NI6SE5

TDB models of NI6SE5 (1): PHASE and CONSTITUENT statements as written

NiSe-21Zob.tdb: NI6SE5, type code %, sha256 1b075f9b26619344…

65: PHASE NI6SE5 % 2 6 5 !
66: CONST NI6SE5 : NI : SE : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-021-00906-9 Ondřej Zobač, Kateřina Buchlovská, Jana Pavlů, Aleš Kroupa, Thermodynamic Description of Binary System Nickel-Selenium, J. Phase Equilib. Diffus. 42, 468-478 (2021).
assessment that models this phase; reports values for this phase
doi:10.1007/bf00905165 K. L. Komarek, K. Wessely, Die Systeme Nickel?Selen und Kobalt?Nickel-Selen, Monatshefte fr Chemie 103, 923-933 (1972).
cited as the source of values for this phase

NISE_B81 (Ni–Se)

Id: phase:ni-se:nise-b81; status assigned
Structure: NiAs · B8_1 · hP4 · P6_3/mmc (194); type st:b8-1-nias-hp4; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–1231.3 K, x(Se) 0.50889–0.57024
Literature: 19 values (19 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:ni-se:nise-b81
paper: paper:10.1007/s11669-021-00906-9:NiSe
tdb: tdb:NiSe-21Zob.tdb:NISE_B81

TDB models of NISE_B81 (1): PHASE and CONSTITUENT statements as written

NiSe-21Zob.tdb: NISE_B81, type code %, sha256 1b075f9b26619344…

70: PHASE NISE_B81 % 2 1 1 !
71: CONST NISE_B81 : NI% SE : SE : !

Example references (3 of 3; assessments first):

doi:10.1007/s11669-021-00906-9 Ondřej Zobač, Kateřina Buchlovská, Jana Pavlů, Aleš Kroupa, Thermodynamic Description of Binary System Nickel-Selenium, J. Phase Equilib. Diffus. 42, 468-478 (2021).
assessment that models this phase; reports values for this phase
doi:10.1007/bf00905165 K. L. Komarek, K. Wessely, Die Systeme Nickel?Selen und Kobalt?Nickel-Selen, Monatshefte fr Chemie 103, 923-933 (1972).
cited as the source of values for this phase
doi:10.3891/acta.chem.scand.26-2085 Fredrik Grønvold, Mats Nygren, D. Simov, H. A. Øye, Sigfrid Svensson, High-Temperature Reaction Calorimeter. Enthalpy of Formation of Iron Selenides and Nickel Selenides at 1050 K., Acta Chem. Scand. 26, 2085-2099 (1972).
cited as the source of values for this phase

NISE2_C2 (Ni–Se)

Id: phase:ni-se:nise2-c2; status assigned
Structure: beta-FeS2 · C2 · cP12 · Pa-3 (205); type st:c2-beta-fes2-cp12; tier A: standard phase name; confidence high
Stoichiometry: Ni 0.3333, Se 0.6667
Stability: stable in 1 of 1 calculated diagram(s): 300–1131.01 K, x(Se) 0.66667–0.66667
Literature: 9 values (9 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:ni-se:nise2-c2
paper: paper:10.1007/s11669-021-00906-9:NiSe2
tdb: tdb:NiSe-21Zob.tdb:NISE2_C2

TDB models of NISE2_C2 (1): PHASE and CONSTITUENT statements as written

NiSe-21Zob.tdb: NISE2_C2, type code %, sha256 1b075f9b26619344…

75: PHASE NISE2_C2 % 2 1 2 !
76: CONST NISE2_C2 : NI : SE : !

Example references (2 of 2; assessments first):

doi:10.1007/s11669-021-00906-9 Ondřej Zobač, Kateřina Buchlovská, Jana Pavlů, Aleš Kroupa, Thermodynamic Description of Binary System Nickel-Selenium, J. Phase Equilib. Diffus. 42, 468-478 (2021).
assessment that models this phase; reports values for this phase
doi:10.1007/bf00905165 K. L. Komarek, K. Wessely, Die Systeme Nickel?Selen und Kobalt?Nickel-Selen, Monatshefte fr Chemie 103, 923-933 (1972).
cited as the source of values for 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}
}