B–Ca phases

7 phases (tier A 4, liquid 1, gas 1, needs_review 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 · B–Ca system page · Markdown · field reference

Phases of the B–Ca system (7)
Phase	Structure	Basis	Stability (calculated)	TDB models
BETA_RHOMBO_B phase:b-ca:b-beta-rhombo		needs_review	stable in 1 of 1 calculated diagram(s): 300–2348 K, x(B) 1–1	1
BCC_A2 phase:b-ca:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 716.03–1870 K, x(B) 0–0	1
CAB6_D21 phase:b-ca:cab6-d21	CaB6 · D2_1 · cP7 · Pm-3m (221)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–3324.99 K, x(B) 0.85714–0.85714	1
FCC_A1 phase:b-ca:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–716.03 K, x(B) 0–0	1
GAS phase:b-ca:gas	gas	gas	stable in 1 of 1 calculated diagram(s): 1795.51–4000 K, x(B) 0–0.52356	1
HCP_A3 phase:b-ca:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 1 calculated diagram(s)	1
LIQUID phase:b-ca:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 1114.6–4000 K, x(B) 0–1	1

BETA_RHOMBO_B (B–Ca)

Id: phase:b-ca:b-beta-rhombo; status needs_review
No structure assigned. Why: name_has_descriptive_tokens:RHOMBO; no_structure_token
Candidate (sgte_mmc2): beta-B · hR105 · R-3m (166) — Hallstedt 2025 mmc2 row for BETA_RHOMBO_B: beta-B
Candidate (tdb_comment): beta-B · hR105 · R-3m — CaB-07Sha.tdb: 'Prototype beta-B (hR105, R-3m)'
Stoichiometry: B 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–2348 K, x(B) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:b-ca:b-beta-rhombo
tdb: tdb:CaB-07Sha.tdb:BETA_RHOMBO_B

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

CaB-07Sha.tdb: BETA_RHOMBO_B, type code %, sha256 378da91365873b16…

50: PHASE BETA_RHOMBO_B % 1 1 !
51: CONST BETA_RHOMBO_B : B : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2006.11.005 Shunli Shang, Tao Wang, Zi-Kui Liu, Thermodynamic modelling of the B–Ca, B–Sr and B–Ba systems, Calphad 31, 286-291 (2007).
assessment that models this phase

BCC_A2 (B–Ca)

Id: phase:b-ca:bcc-a2; status assigned
Structure: W · A2 · cI2 · Im-3m (229); type st:a2-w-ci2; tier A: standard phase name; confidence high
Stoichiometry: Ca 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 716.03–1870 K, x(B) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:b-ca:bcc-a2
tdb: tdb:CaB-07Sha.tdb:BCC_A2

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

CaB-07Sha.tdb: BCC_A2, type code %B, sha256 378da91365873b16…

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

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2006.11.005 Shunli Shang, Tao Wang, Zi-Kui Liu, Thermodynamic modelling of the B–Ca, B–Sr and B–Ba systems, Calphad 31, 286-291 (2007).
assessment that models this phase

CAB6_D21 (B–Ca)

Id: phase:b-ca:cab6-d21; status assigned
Structure: CaB6 · D2_1 · cP7 · Pm-3m (221); type st:d2-1-cab6-cp7; tier A: standard phase name; confidence high
Caveat: DFT agrees: on-hull mp-aaaaabhh and oqmd-5116, space group 221
Stoichiometry: B 0.8571, Ca 0.1429
Stability: stable in 1 of 1 calculated diagram(s): 300–3324.99 K, x(B) 0.85714–0.85714
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:b-ca:cab6-d21
mp: mp:mp-aaaaabhh
oqmd: oqmd:oqmd-5116
tdb: tdb:CaB-07Sha.tdb:CAB6_D21

TDB models of CAB6_D21 (1): PHASE and CONSTITUENT statements as written

CaB-07Sha.tdb: CAB6_D21, type code %, sha256 378da91365873b16…

55: PHASE CAB6_D21 % 2 1 6 !
56: CONST CAB6_D21 : CA : B : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2006.11.005 Shunli Shang, Tao Wang, Zi-Kui Liu, Thermodynamic modelling of the B–Ca, B–Sr and B–Ba systems, Calphad 31, 286-291 (2007).
assessment that models this phase

FCC_A1 (B–Ca)

Id: phase:b-ca:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
Stoichiometry: Ca 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–716.03 K, x(B) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:b-ca:fcc-a1
tdb: tdb:CaB-07Sha.tdb:FCC_A1

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

CaB-07Sha.tdb: FCC_A1, type code %A, sha256 378da91365873b16…

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

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2006.11.005 Shunli Shang, Tao Wang, Zi-Kui Liu, Thermodynamic modelling of the B–Ca, B–Sr and B–Ba systems, Calphad 31, 286-291 (2007).
assessment that models this phase

GAS (B–Ca)

Id: phase:b-ca:gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1795.51–4000 K, x(B) 0–0.52356
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:b-ca:gas
tdb: tdb:CaB-07Sha.tdb:GAS

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

CaB-07Sha.tdb: GAS, type code %, sha256 378da91365873b16…

58: PHASE GAS:G % 1 1 !
59: CONST GAS:G : B B2 CA CA2 : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2006.11.005 Shunli Shang, Tao Wang, Zi-Kui Liu, Thermodynamic modelling of the B–Ca, B–Sr and B–Ba systems, Calphad 31, 286-291 (2007).
assessment that models this phase

HCP_A3 (B–Ca)

Id: phase:b-ca: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: Ca 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:b-ca:hcp-a3
tdb: tdb:CaB-07Sha.tdb:HCP_A3

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

CaB-07Sha.tdb: HCP_A3, type code %A, sha256 378da91365873b16…

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

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2006.11.005 Shunli Shang, Tao Wang, Zi-Kui Liu, Thermodynamic modelling of the B–Ca, B–Sr and B–Ba systems, Calphad 31, 286-291 (2007).
assessment that models this phase

LIQUID (B–Ca)

Id: phase:b-ca:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1114.6–4000 K, x(B) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:b-ca:liquid
tdb: tdb:CaB-07Sha.tdb:LIQUID

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

CaB-07Sha.tdb: LIQUID, type code %, sha256 378da91365873b16…

30: PHASE LIQUID:L % 1 1 !
31: CONST LIQUID:L : B CA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2006.11.005 Shunli Shang, Tao Wang, Zi-Kui Liu, Thermodynamic modelling of the B–Ca, B–Sr and B–Ba systems, Calphad 31, 286-291 (2007).
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}
}