C–P phases

8 phases (tier A 5, liquid 1, needs_review 2); 3 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–P system page · Markdown · field reference

Phases of the C–P system (8)
Phase	Structure	Basis	Stability (calculated)	TDB models
DIAMOND_A4 phase:c-p:a4-diamond	C (diamond) · A4 · cF8 · Fd-3m (227)	tier A: standard phase name	not stable in 1 calculated diagram(s)	1
GRAPHITE_A9 phase:c-p:a9-graphite	C (graphite) · A9 · hP4 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–4000 K, x(P) 0–0	1
BCC_A2 phase:c-p:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	not stable in 1 calculated diagram(s)	1
FCC_A1 phase:c-p:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	not stable in 1 calculated diagram(s)	1
HCP_A3 phase:c-p:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 1 calculated diagram(s)	1
LIQUID phase:c-p:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 852.15–4000 K, x(P) 0.33818–1	1
RED_P phase:c-p:p-red		needs_review	stable in 1 of 1 calculated diagram(s): 300–852.15 K, x(P) 1–1	1
WHITE_P phase:c-p:p-white		needs_review	not stable in 1 calculated diagram(s)	1

DIAMOND_A4 (C–P)

Id: phase:c-p: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 1 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-p:a4-diamond
tdb: tdb:CP-90Gus.tdb:DIAMOND_A4

TDB models of DIAMOND_A4 (1): PHASE and CONSTITUENT statements as written

CP-90Gus.tdb: DIAMOND_A4, type code %, sha256 428a91c42e8a470f…

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

GRAPHITE_A9 (C–P)

Id: phase:c-p: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 1 of 1 calculated diagram(s): 300–4000 K, x(P) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-p:a9-graphite
tdb: tdb:CP-90Gus.tdb:GRAPHITE_A9

TDB models of GRAPHITE_A9 (1): PHASE and CONSTITUENT statements as written

CP-90Gus.tdb: GRAPHITE_A9, type code %, sha256 428a91c42e8a470f…

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

BCC_A2 (C–P)

Id: phase:c-p:bcc-a2; status assigned
Structure: W · A2 · cI2 · Im-3m (229); type st:a2-w-ci2; tier A: standard phase name; confidence high
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:c-p:bcc-a2
tdb: tdb:CP-90Gus.tdb:BCC_A2

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

CP-90Gus.tdb: BCC_A2, type code %B, sha256 428a91c42e8a470f…

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

FCC_A1 (C–P)

Id: phase:c-p:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
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:c-p:fcc-a1
tdb: tdb:CP-90Gus.tdb:FCC_A1

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

CP-90Gus.tdb: FCC_A1, type code %A, sha256 428a91c42e8a470f…

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

HCP_A3 (C–P)

Id: phase:c-p: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 1 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-p:hcp-a3
tdb: tdb:CP-90Gus.tdb:HCP_A3

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

CP-90Gus.tdb: HCP_A3, type code %A, sha256 428a91c42e8a470f…

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

LIQUID (C–P)

Id: phase:c-p:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 852.15–4000 K, x(P) 0.33818–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-p:liquid
tdb: tdb:CP-90Gus.tdb:LIQUID

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

CP-90Gus.tdb: LIQUID, type code %, sha256 428a91c42e8a470f…

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

RED_P (C–P)

Id: phase:c-p:p-red; status needs_review
No structure assigned. Why: name_has_descriptive_tokens:RED; no_structure_token
Candidate (sgte_mmc2): (Red P) — Hallstedt 2025 mmc2 row for RED_P: Red P
Stoichiometry: P 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–852.15 K, x(P) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-p:p-red
tdb: tdb:CP-90Gus.tdb:RED_P

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

CP-90Gus.tdb: RED_P, type code %, sha256 428a91c42e8a470f…

64: PHASE RED_P % 1 1 !
65: CONST RED_P : P : !

WHITE_P (C–P)

Id: phase:c-p:p-white; status needs_review
No structure assigned. Why: name_has_descriptive_tokens:WHITE; no_structure_token
Candidate (sgte_mmc2): (White P) — Hallstedt 2025 mmc2 row for WHITE_P: White P
Stoichiometry: P 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:c-p:p-white
tdb: tdb:CP-90Gus.tdb:WHITE_P

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

CP-90Gus.tdb: WHITE_P, type code %, sha256 428a91c42e8a470f…

59: PHASE WHITE_P % 1 1 !
60: CONST WHITE_P : P : !

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}
}