C–Ni phases

7 phases (tier A 6, liquid 1); 4 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 · C–Ni system page · Markdown · field reference

Phases of the C–Ni system (7)
Phase	Structure	Basis	Stability (calculated)	TDB models
DIAMOND_A4 phase:c-ni:a4-diamond	C (diamond) · A4 · cF8 · Fd-3m (227)	tier A: standard phase name	not stable in 4 calculated diagram(s)	4
GRAPHITE_A9 phase:c-ni:a9-graphite	C (graphite) · A9 · hP4 · P6_3/mmc (194)	tier A: standard phase name	stable in 4 of 4 calculated diagram(s): 300–4000 K, x(C) 1–1	4
BCC_A2 phase:c-ni:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 2 of 4 calculated diagram(s): 3008.4–4000 K, x(C) 0.35583–0.59326	4
CEMENTITE_D011 phase:c-ni:cementite-d011	Fe3C · D0_11 · oP16 · Pnma (62)	tier A: standard phase name	not stable in 4 calculated diagram(s)	4
FCC_A1 phase:c-ni:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 4 of 4 calculated diagram(s): 300–2974.54 K, x(C) 0–0.02743	4
HCP_A3 phase:c-ni:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 4 calculated diagram(s)	4
LIQUID phase:c-ni:liquid	liquid	liquid	stable in 4 of 4 calculated diagram(s): 1597.57–4000 K, x(C) 0–0.55948	4

DIAMOND_A4 (C–Ni)

Id: phase:c-ni:a4-diamond; status assigned
Structure: C (diamond) · A4 · cF8 · Fd-3m (227); type st:a4-c-diamond-cf8; tier A: standard phase name; confidence high
Stoichiometry: C 1.0000
Stability: not stable in 4 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:c-ni:a4-diamond
tdb: tdb:NiC-06Hal.tdb:DIAMOND_A4, tdb:NiC-22Oik.tdb:DIAMOND_A4, tdb:NiC-87Gab-LB.tdb:DIAMOND_A4, tdb:NiC-92Lee.tdb:DIAMOND_A4

TDB models of DIAMOND_A4 (4): PHASE and CONSTITUENT statements as written

NiC-06Hal.tdb: DIAMOND_A4, type code %, sha256 9c685cddb0304c2f…

45: PHASE DIAMOND_A4 % 1 1 !
46: CONST DIAMOND_A4 : C : !

NiC-22Oik.tdb: DIAMOND_A4, type code %, sha256 10d4397973f84604…

43: PHASE DIAMOND_A4 % 1 1 !
44: CONST DIAMOND_A4 : C : !

NiC-87Gab-LB.tdb: DIAMOND_A4, type code %, sha256 c412cb38ff96497c…

49: PHASE DIAMOND_A4 % 1 1 !
50: CONST DIAMOND_A4 : C : !

NiC-92Lee.tdb: DIAMOND_A4, type code %, sha256 d316a2888dd883af…

42: PHASE DIAMOND_A4 % 1 1 !
43: CONST DIAMOND_A4 : C : !

Example references (3 of 3; assessments first):

doi:10.1007/s11669-022-00995-0 Katsunari Oikawa, Nobufumi Ueshima, Experimental Investigation and Thermodynamic Assessment of Ni–B and Ni–B–C Systems, J. Phase Equilib. Diffus. 43, 814-826 (2022).
assessment that models this phase
doi:10.1016/0364-5916(87)90039-3 Armand Gabriel, Per Gustafson, Ibrahim Ansara, A thermodynamic evaluation of the C-Fe-Ni system, Calphad 11, 203-218 (1987).
assessment that models this phase
doi:10.1016/0364-5916(92)90002-F B.-J. Lee, Calphad, 16, 121-49(1992).
assessment that models this phase

GRAPHITE_A9 (C–Ni)

Id: phase:c-ni:a9-graphite; status assigned
Structure: C (graphite) · A9 · hP4 · P6_3/mmc (194); type st:a9-c-graphite-hp4; tier A: standard phase name; confidence high
Stoichiometry: C 1.0000
Stability: stable in 4 of 4 calculated diagram(s): 300–4000 K, x(C) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:c-ni:a9-graphite
tdb: tdb:NiC-06Hal.tdb:GRAPHITE_A9, tdb:NiC-22Oik.tdb:GRAPHITE_A9, tdb:NiC-87Gab-LB.tdb:GRAPHITE_A9, tdb:NiC-92Lee.tdb:GRAPHITE_A9

TDB models of GRAPHITE_A9 (4): PHASE and CONSTITUENT statements as written

NiC-06Hal.tdb: GRAPHITE_A9, type code %, sha256 9c685cddb0304c2f…

50: PHASE GRAPHITE_A9 % 1 1 !
51: CONST GRAPHITE_A9 : C : !

NiC-22Oik.tdb: GRAPHITE_A9, type code %, sha256 10d4397973f84604…

48: PHASE GRAPHITE_A9 % 1 1 !
49: CONST GRAPHITE_A9 : C : !

NiC-87Gab-LB.tdb: GRAPHITE_A9, type code %, sha256 c412cb38ff96497c…

54: PHASE GRAPHITE_A9 % 1 1 !
55: CONST GRAPHITE_A9 : C : !

NiC-92Lee.tdb: GRAPHITE_A9, type code %, sha256 d316a2888dd883af…

47: PHASE GRAPHITE_A9 % 1 1 !
48: CONST GRAPHITE_A9 : C : !

Example references (3 of 3; assessments first):

doi:10.1007/s11669-022-00995-0 Katsunari Oikawa, Nobufumi Ueshima, Experimental Investigation and Thermodynamic Assessment of Ni–B and Ni–B–C Systems, J. Phase Equilib. Diffus. 43, 814-826 (2022).
assessment that models this phase
doi:10.1016/0364-5916(87)90039-3 Armand Gabriel, Per Gustafson, Ibrahim Ansara, A thermodynamic evaluation of the C-Fe-Ni system, Calphad 11, 203-218 (1987).
assessment that models this phase
doi:10.1016/0364-5916(92)90002-F B.-J. Lee, Calphad, 16, 121-49(1992).
assessment that models this phase

BCC_A2 (C–Ni)

Id: phase:c-ni: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 2 of 4 calculated diagram(s): 3008.4–4000 K, x(C) 0.35583–0.59326
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:c-ni:bcc-a2
tdb: tdb:NiC-06Hal.tdb:BCC_A2, tdb:NiC-22Oik.tdb:BCC_A2, tdb:NiC-87Gab-LB.tdb:BCC_A2, tdb:NiC-92Lee.tdb:BCC_A2

TDB models of BCC_A2 (4): PHASE and CONSTITUENT statements as written

NiC-06Hal.tdb: BCC_A2, type code %B, sha256 9c685cddb0304c2f…

35: PHASE BCC_A2 %B 2 1 3 !
36: CONST BCC_A2 : NI : C VA% : !

NiC-22Oik.tdb: BCC_A2, type code %B, sha256 10d4397973f84604…

33: PHASE BCC_A2 %B 2 1 3 !
34: CONST BCC_A2 : NI : C VA% : !

NiC-87Gab-LB.tdb: BCC_A2, type code %B, sha256 c412cb38ff96497c…

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

NiC-92Lee.tdb: BCC_A2, type code %B, sha256 d316a2888dd883af…

32: PHASE BCC_A2 %B 2 1 3 !
33: CONST BCC_A2 : NI : C VA% : !

Example references (3 of 3; assessments first):

doi:10.1007/s11669-022-00995-0 Katsunari Oikawa, Nobufumi Ueshima, Experimental Investigation and Thermodynamic Assessment of Ni–B and Ni–B–C Systems, J. Phase Equilib. Diffus. 43, 814-826 (2022).
assessment that models this phase
doi:10.1016/0364-5916(87)90039-3 Armand Gabriel, Per Gustafson, Ibrahim Ansara, A thermodynamic evaluation of the C-Fe-Ni system, Calphad 11, 203-218 (1987).
assessment that models this phase
doi:10.1016/0364-5916(92)90002-F B.-J. Lee, Calphad, 16, 121-49(1992).
assessment that models this phase

CEMENTITE_D011 (C–Ni)

Id: phase:c-ni:cementite-d011; status assigned
Structure: Fe3C · D0_11 · oP16 · Pnma (62); type st:d0-11-fe3c-op16; tier A: standard phase name; confidence high
Stoichiometry: C 0.2500, Ni 0.7500
Stability: not stable in 4 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:c-ni:cementite-d011
tdb: tdb:NiC-06Hal.tdb:CEMENTITE_D011, tdb:NiC-22Oik.tdb:CEMENTITE_D011, tdb:NiC-87Gab-LB.tdb:CEMENTITE_D011, tdb:NiC-92Lee.tdb:CEMENTITE_D011

TDB models of CEMENTITE_D011 (4): PHASE and CONSTITUENT statements as written

NiC-06Hal.tdb: CEMENTITE_D011, type code %, sha256 9c685cddb0304c2f…

55: PHASE CEMENTITE_D011 % 2 3 1 !
56: CONST CEMENTITE_D011 : NI : C : !

NiC-22Oik.tdb: CEMENTITE_D011, type code %, sha256 10d4397973f84604…

53: PHASE CEMENTITE_D011 % 2 3 1 !
54: CONST CEMENTITE_D011 : NI : C : !

NiC-87Gab-LB.tdb: CEMENTITE_D011, type code %, sha256 c412cb38ff96497c…

59: PHASE CEMENTITE_D011 % 2 3 1 !
60: CONST CEMENTITE_D011 : NI : C : !

NiC-92Lee.tdb: CEMENTITE_D011, type code %, sha256 d316a2888dd883af…

52: PHASE CEMENTITE_D011 % 2 3 1 !
53: CONST CEMENTITE_D011 : NI : C : !

Example references (3 of 3; assessments first):

doi:10.1007/s11669-022-00995-0 Katsunari Oikawa, Nobufumi Ueshima, Experimental Investigation and Thermodynamic Assessment of Ni–B and Ni–B–C Systems, J. Phase Equilib. Diffus. 43, 814-826 (2022).
assessment that models this phase
doi:10.1016/0364-5916(87)90039-3 Armand Gabriel, Per Gustafson, Ibrahim Ansara, A thermodynamic evaluation of the C-Fe-Ni system, Calphad 11, 203-218 (1987).
assessment that models this phase
doi:10.1016/0364-5916(92)90002-F B.-J. Lee, Calphad, 16, 121-49(1992).
assessment that models this phase

FCC_A1 (C–Ni)

Id: phase:c-ni:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
Stability: stable in 4 of 4 calculated diagram(s): 300–2974.54 K, x(C) 0–0.02743
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:c-ni:fcc-a1
tdb: tdb:NiC-06Hal.tdb:FCC_A1, tdb:NiC-22Oik.tdb:FCC_A1, tdb:NiC-87Gab-LB.tdb:FCC_A1, tdb:NiC-92Lee.tdb:FCC_A1

TDB models of FCC_A1 (4): PHASE and CONSTITUENT statements as written

NiC-06Hal.tdb: FCC_A1, type code %A, sha256 9c685cddb0304c2f…

30: PHASE FCC_A1 %A 2 1 1 !
31: CONST FCC_A1 : NI : C VA% : !

NiC-22Oik.tdb: FCC_A1, type code %A, sha256 10d4397973f84604…

28: PHASE FCC_A1 %A 2 1 1 !
29: CONST FCC_A1 : NI : C VA% : !

NiC-87Gab-LB.tdb: FCC_A1, type code %A, sha256 c412cb38ff96497c…

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

NiC-92Lee.tdb: FCC_A1, type code %A, sha256 d316a2888dd883af…

27: PHASE FCC_A1 %A 2 1 1 !
28: CONST FCC_A1 : NI : C VA% : !

Example references (3 of 3; assessments first):

doi:10.1007/s11669-022-00995-0 Katsunari Oikawa, Nobufumi Ueshima, Experimental Investigation and Thermodynamic Assessment of Ni–B and Ni–B–C Systems, J. Phase Equilib. Diffus. 43, 814-826 (2022).
assessment that models this phase
doi:10.1016/0364-5916(87)90039-3 Armand Gabriel, Per Gustafson, Ibrahim Ansara, A thermodynamic evaluation of the C-Fe-Ni system, Calphad 11, 203-218 (1987).
assessment that models this phase
doi:10.1016/0364-5916(92)90002-F B.-J. Lee, Calphad, 16, 121-49(1992).
assessment that models this phase

HCP_A3 (C–Ni)

Id: phase:c-ni: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: not stable in 4 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:c-ni:hcp-a3
tdb: tdb:NiC-06Hal.tdb:HCP_A3, tdb:NiC-22Oik.tdb:HCP_A3, tdb:NiC-87Gab-LB.tdb:HCP_A3, tdb:NiC-92Lee.tdb:HCP_A3

TDB models of HCP_A3 (4): PHASE and CONSTITUENT statements as written

NiC-06Hal.tdb: HCP_A3, type code %A, sha256 9c685cddb0304c2f…

40: PHASE HCP_A3 %A 2 1 0.5 !
41: CONST HCP_A3 : NI : C VA% : !

NiC-22Oik.tdb: HCP_A3, type code %A, sha256 10d4397973f84604…

38: PHASE HCP_A3 %A 2 1 0.5 !
39: CONST HCP_A3 : NI : C VA% : !

NiC-87Gab-LB.tdb: HCP_A3, type code %A, sha256 c412cb38ff96497c…

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

NiC-92Lee.tdb: HCP_A3, type code %A, sha256 d316a2888dd883af…

37: PHASE HCP_A3 %A 2 1 0.5 !
38: CONST HCP_A3 : NI : C VA% : !

Example references (3 of 3; assessments first):

doi:10.1007/s11669-022-00995-0 Katsunari Oikawa, Nobufumi Ueshima, Experimental Investigation and Thermodynamic Assessment of Ni–B and Ni–B–C Systems, J. Phase Equilib. Diffus. 43, 814-826 (2022).
assessment that models this phase
doi:10.1016/0364-5916(87)90039-3 Armand Gabriel, Per Gustafson, Ibrahim Ansara, A thermodynamic evaluation of the C-Fe-Ni system, Calphad 11, 203-218 (1987).
assessment that models this phase
doi:10.1016/0364-5916(92)90002-F B.-J. Lee, Calphad, 16, 121-49(1992).
assessment that models this phase

LIQUID (C–Ni)

Id: phase:c-ni:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 4 of 4 calculated diagram(s): 1597.57–4000 K, x(C) 0–0.55948
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:c-ni:liquid
tdb: tdb:NiC-06Hal.tdb:LIQUID, tdb:NiC-22Oik.tdb:LIQUID, tdb:NiC-87Gab-LB.tdb:LIQUID, tdb:NiC-92Lee.tdb:LIQUID

TDB models of LIQUID (4): PHASE and CONSTITUENT statements as written

NiC-06Hal.tdb: LIQUID, type code %, sha256 9c685cddb0304c2f…

25: PHASE LIQUID:L % 1 1 !
26: CONST LIQUID:L : C NI : !

NiC-22Oik.tdb: LIQUID, type code %, sha256 10d4397973f84604…

23: PHASE LIQUID:L % 1 1 !
24: CONST LIQUID:L : C NI : !

NiC-87Gab-LB.tdb: LIQUID, type code %, sha256 c412cb38ff96497c…

29: PHASE LIQUID:L % 1 1 !
30: CONST LIQUID:L : C NI : !

NiC-92Lee.tdb: LIQUID, type code %, sha256 d316a2888dd883af…

22: PHASE LIQUID:L % 1 1 !
23: CONST LIQUID:L : C NI : !

Example references (3 of 3; assessments first):

doi:10.1007/s11669-022-00995-0 Katsunari Oikawa, Nobufumi Ueshima, Experimental Investigation and Thermodynamic Assessment of Ni–B and Ni–B–C Systems, J. Phase Equilib. Diffus. 43, 814-826 (2022).
assessment that models this phase
doi:10.1016/0364-5916(87)90039-3 Armand Gabriel, Per Gustafson, Ibrahim Ansara, A thermodynamic evaluation of the C-Fe-Ni system, Calphad 11, 203-218 (1987).
assessment that models this phase
doi:10.1016/0364-5916(92)90002-F B.-J. Lee, Calphad, 16, 121-49(1992).
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}
}