Bi–Cu phases

5 phases (tier A 4, liquid 1); 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 · Bi–Cu system page · Markdown · field reference

Phases of the Bi–Cu system (5)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
RHOMBOHEDRAL_A7 phase:bi-cu:a7-rhombohedral	alpha-As · A7 · hR2 · R-3m (166)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–544.55 K, x(Cu) 0–0	0	2
BCC_A2 phase:bi-cu:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	not stable in 2 calculated diagram(s)	0	2
FCC_A1 phase:bi-cu:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–2499.52 K, x(Cu) 0.99875–1	0	2
HCP_A3 phase:bi-cu:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 2 calculated diagram(s)	0	2
LIQUID phase:bi-cu:liquid	liquid	liquid	stable in 2 of 2 calculated diagram(s): 543.66–2500 K, x(Cu) 0–1	3	2

RHOMBOHEDRAL_A7 (Bi–Cu)

Id: phase:bi-cu:a7-rhombohedral; status assigned
Structure: alpha-As · A7 · hR2 · R-3m (166); type st:a7-alpha-as-hr2; tier A: standard phase name; confidence high
Stoichiometry: Bi 1.0000
Stability: stable in 2 of 2 calculated diagram(s): 300–544.55 K, x(Cu) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:bi-cu:a7-rhombohedral
tdb: tdb:BiCu-89Tep-LB.tdb:RHOMBOHEDRAL_A7, tdb:BiCu-90Tep.tdb:RHOMBOHEDRAL_A7

TDB models of RHOMBOHEDRAL_A7 (2): PHASE and CONSTITUENT statements as written

BiCu-89Tep-LB.tdb: RHOMBOHEDRAL_A7, type code %, sha256 f9abbe5e46364f6c…

48: PHASE RHOMBOHEDRAL_A7 % 1 1 !
49: CONST RHOMBOHEDRAL_A7 : BI : !

BiCu-90Tep.tdb: RHOMBOHEDRAL_A7, type code %, sha256 ee69358a29e6f6d1…

51: PHASE RHOMBOHEDRAL_A7 % 1 1 !
52: CONST RHOMBOHEDRAL_A7 : BI : !

Example references (1 of 1; assessments first):

doi:10.1016/0040-6031(90)80598-S O. Teppo, J. Niemela, P. Taskinen, Thermochim. Acta, 173, 137-50 (1990)
assessment that models this phase

BCC_A2 (Bi–Cu)

Id: phase:bi-cu: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 2 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:bi-cu:bcc-a2
tdb: tdb:BiCu-89Tep-LB.tdb:BCC_A2, tdb:BiCu-90Tep.tdb:BCC_A2

TDB models of BCC_A2 (2): PHASE and CONSTITUENT statements as written

BiCu-89Tep-LB.tdb: BCC_A2, type code %, sha256 f9abbe5e46364f6c…

38: PHASE BCC_A2 % 2 1 3 !
39: CONST BCC_A2 : BI CU : VA : !

BiCu-90Tep.tdb: BCC_A2, type code %B, sha256 ee69358a29e6f6d1…

41: PHASE BCC_A2 %B 2 1 3 !
42: CONST BCC_A2 : BI CU : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/0040-6031(90)80598-S O. Teppo, J. Niemela, P. Taskinen, Thermochim. Acta, 173, 137-50 (1990)
assessment that models this phase

FCC_A1 (Bi–Cu)

Id: phase:bi-cu: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 2 of 2 calculated diagram(s): 300–2499.52 K, x(Cu) 0.99875–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:bi-cu:fcc-a1
tdb: tdb:BiCu-89Tep-LB.tdb:FCC_A1, tdb:BiCu-90Tep.tdb:FCC_A1

TDB models of FCC_A1 (2): PHASE and CONSTITUENT statements as written

BiCu-89Tep-LB.tdb: FCC_A1, type code %, sha256 f9abbe5e46364f6c…

33: PHASE FCC_A1 % 2 1 1 !
34: CONST FCC_A1 : BI CU% : VA : !

BiCu-90Tep.tdb: FCC_A1, type code %A, sha256 ee69358a29e6f6d1…

36: PHASE FCC_A1 %A 2 1 1 !
37: CONST FCC_A1 : BI CU% : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/0040-6031(90)80598-S O. Teppo, J. Niemela, P. Taskinen, Thermochim. Acta, 173, 137-50 (1990)
assessment that models this phase

HCP_A3 (Bi–Cu)

Id: phase:bi-cu: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 2 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:bi-cu:hcp-a3
tdb: tdb:BiCu-89Tep-LB.tdb:HCP_A3, tdb:BiCu-90Tep.tdb:HCP_A3

TDB models of HCP_A3 (2): PHASE and CONSTITUENT statements as written

BiCu-89Tep-LB.tdb: HCP_A3, type code %, sha256 f9abbe5e46364f6c…

43: PHASE HCP_A3 % 2 1 0.5 !
44: CONST HCP_A3 : BI CU : VA: !

BiCu-90Tep.tdb: HCP_A3, type code %A, sha256 ee69358a29e6f6d1…

46: PHASE HCP_A3 %A 2 1 0.5 !
47: CONST HCP_A3 : BI CU : VA: !

Example references (1 of 1; assessments first):

doi:10.1016/0040-6031(90)80598-S O. Teppo, J. Niemela, P. Taskinen, Thermochim. Acta, 173, 137-50 (1990)
assessment that models this phase

LIQUID (Bi–Cu)

Id: phase:bi-cu:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 543.66–2500 K, x(Cu) 0–1
Literature: 3 values (0 accepted) from 1 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:bi-cu:liquid
paper: paper:10.1002/crat.200800391:liquid
tdb: tdb:BiCu-89Tep-LB.tdb:LIQUID, tdb:BiCu-90Tep.tdb:LIQUID

TDB models of LIQUID (2): PHASE and CONSTITUENT statements as written

BiCu-89Tep-LB.tdb: LIQUID, type code %, sha256 f9abbe5e46364f6c…

28: PHASE LIQUID:L % 1 1 !
29: CONST LIQUID:L : BI CU : !

BiCu-90Tep.tdb: LIQUID, type code %, sha256 ee69358a29e6f6d1…

31: PHASE LIQUID:L % 1 1 !
32: CONST LIQUID:L : BI CU : !

Example references (2 of 2; assessments first):

doi:10.1016/0040-6031(90)80598-S O. Teppo, J. Niemela, P. Taskinen, Thermochim. Acta, 173, 137-50 (1990)
assessment that models this phase
doi:10.1002/crat.200800391 G. Vassilev, V. Gandova, P. Docheva, Comments and reconciliation of the Ni–Bi‐system thermodynamic reassessments, Cryst. Res. Technol. 44, 25-30 (2009).
reports 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}
}