# B–Sr phases

> B–Sr system: 7 phases (tier A 4, liquid 1, gas 1, needs_review 1); 6 stable in a calculated diagram in the ORCHID phase registry, with names, structure type when the stored evidence supports an assignment under the stated tier rules, calculated stability, verbatim TDB PHASE/CONSTITUENT statements and example references.

HTML: https://data.orchid-project.org/phases/pages/B-SR.html · Markdown: https://data.orchid-project.org/phases/pages/B-SR.md

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](https://orchid-project.org/phases/?q=B-SR) · [full JSON](https://data.orchid-project.org/phases/systems/B-SR.json) · [B–Sr system page](https://data.orchid-project.org/systems/B-SR.html) · [Markdown](https://data.orchid-project.org/phases/pages/B-SR.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md)

Table: Phases of the B–Sr system (7)

| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---:|---:|
| [BETA_RHOMBO_B](#phase-b-sr-b-beta-rhombo); _phase:b-sr:b-beta-rhombo_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 300–2349 K, x(B) 1–1 | 0 | 1 |
| [BCC_A2](#phase-b-sr-bcc-a2); _phase:b-sr:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 820–1485 K, x(B) 0–0 | 0 | 1 |
| [FCC_A1](#phase-b-sr-fcc-a1); _phase:b-sr:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–820 K, x(B) 0–0 | 0 | 1 |
| [GAS](#phase-b-sr-gas); _phase:b-sr:gas_ | gas | gas | stable in 1 of 1 calculated diagram(s): 1644.63–4000 K, x(B) 0–0.52362 | 1 | 1 |
| [HCP_A3](#phase-b-sr-hcp-a3); _phase:b-sr: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-b-sr-liquid); _phase:b-sr:liquid_ | liquid | liquid | stable in 1 of 1 calculated diagram(s): 1049.83–4000 K, x(B) 0–1 | 0 | 1 |
| [SRB6_D21](#phase-b-sr-srb6-d21); _phase:b-sr:srb6-d21_ | CaB6 · D2_1 · cP7 · Pm-3m (221) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–3154.9 K, x(B) 0.85714–0.85714 | 0 | 1 |

## BETA_RHOMBO_B (B–Sr)

- Id: `phase:b-sr: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 — SrB-07Sha.tdb: 'Prototype beta-B (hR105, R-3m)'
- Stoichiometry: B 1.0000
- Stability: stable in 1 of 1 calculated diagram(s): 300–2349 K, x(B) 1–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:b-sr:b-beta-rhombo)

Names (2): _corpus: _corpus:phase:b-sr:b-beta-rhombo  
_tdb: _tdb:SrB-07Sha.tdb:BETA_RHOMBO_B  


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

[SrB-07Sha.tdb](https://orchid-project.org/data/databases/sgte-binary/SrB-07Sha.tdb): BETA_RHOMBO_B, type code %, sha256 `0a3ac53840bde6b1…`

~~~~text
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](https://doi.org/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–Sr)

- Id: `phase:b-sr:bcc-a2`; status `assigned`
- Structure: W · A2 · cI2 · Im-3m (229); type `st:a2-w-ci2`; tier A: standard phase name; confidence high
- Stoichiometry: Sr 1.0000
- Stability: stable in 1 of 1 calculated diagram(s): 820–1485 K, x(B) 0–0
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:b-sr:bcc-a2)

Names (2): _corpus: _corpus:phase:b-sr:bcc-a2  
_tdb: _tdb:SrB-07Sha.tdb:BCC_A2  


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

[SrB-07Sha.tdb](https://orchid-project.org/data/databases/sgte-binary/SrB-07Sha.tdb): BCC_A2, type code %B, sha256 `0a3ac53840bde6b1…`

~~~~text
40: PHASE BCC_A2 %B 2 1 3 !
41: CONST BCC_A2 : SR : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2006.11.005](https://doi.org/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–Sr)

- Id: `phase:b-sr:fcc-a1`; status `assigned`
- Structure: Cu · A1 · cF4 · Fm-3m (225); type `st:a1-cu-cf4`; tier A: standard phase name; confidence high
- Stoichiometry: Sr 1.0000
- Stability: stable in 1 of 1 calculated diagram(s): 300–820 K, x(B) 0–0
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:b-sr:fcc-a1)

Names (2): _corpus: _corpus:phase:b-sr:fcc-a1  
_tdb: _tdb:SrB-07Sha.tdb:FCC_A1  


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

[SrB-07Sha.tdb](https://orchid-project.org/data/databases/sgte-binary/SrB-07Sha.tdb): FCC_A1, type code %A, sha256 `0a3ac53840bde6b1…`

~~~~text
35: PHASE FCC_A1 %A 2 1 1 !
36: CONST FCC_A1 : SR : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2006.11.005](https://doi.org/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–Sr)

- Id: `phase:b-sr:gas`; status `assigned`
- Structure: gas; type `st:gas`; gas; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 1644.63–4000 K, x(B) 0–0.52362
- Literature: 1 values (1 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:b-sr:gas)

Names (3): _corpus: _corpus:phase:b-sr:gas  
_paper: _paper:10.1016/j.calphad.2006.11.005:gas  
_tdb: _tdb:SrB-07Sha.tdb:GAS  


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

[SrB-07Sha.tdb](https://orchid-project.org/data/databases/sgte-binary/SrB-07Sha.tdb): GAS, type code %, sha256 `0a3ac53840bde6b1…`

~~~~text
58: PHASE GAS:G % 1 1 !
59: CONST GAS:G : B B2 SR SR2 : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2006.11.005](https://doi.org/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; reports values for this phase_

## HCP_A3 (B–Sr)

- Id: `phase:b-sr: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: Sr 1.0000
- Stability: not stable in 1 calculated diagram(s)
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:b-sr:hcp-a3)

Names (2): _corpus: _corpus:phase:b-sr:hcp-a3  
_tdb: _tdb:SrB-07Sha.tdb:HCP_A3  


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

[SrB-07Sha.tdb](https://orchid-project.org/data/databases/sgte-binary/SrB-07Sha.tdb): HCP_A3, type code %A, sha256 `0a3ac53840bde6b1…`

~~~~text
45: PHASE HCP_A3 %A 2 1 0.5 !
46: CONST HCP_A3 : SR : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2006.11.005](https://doi.org/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–Sr)

- Id: `phase:b-sr:liquid`; status `assigned`
- Structure: liquid; type `st:liquid`; liquid; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 1049.83–4000 K, x(B) 0–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:b-sr:liquid)

Names (2): _corpus: _corpus:phase:b-sr:liquid  
_tdb: _tdb:SrB-07Sha.tdb:LIQUID  


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

[SrB-07Sha.tdb](https://orchid-project.org/data/databases/sgte-binary/SrB-07Sha.tdb): LIQUID, type code %, sha256 `0a3ac53840bde6b1…`

~~~~text
30: PHASE LIQUID:L % 1 1 !
31: CONST LIQUID:L : B SR : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2006.11.005](https://doi.org/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_

## SRB6_D21 (B–Sr)

- Id: `phase:b-sr:srb6-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-aaaaaaji and oqmd-646494, space group 221
- Stoichiometry: B 0.8571, Sr 0.1429
- Stability: stable in 1 of 1 calculated diagram(s): 300–3154.9 K, x(B) 0.85714–0.85714
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:b-sr:srb6-d21)

Names (4): _corpus: _corpus:phase:b-sr:srb6-d21  
_mp: _mp:mp-aaaaaaji  
_oqmd: _oqmd:oqmd-646494  
_tdb: _tdb:SrB-07Sha.tdb:SRB6_D21  


### TDB models of SRB6_D21 (1): PHASE and CONSTITUENT statements as written

[SrB-07Sha.tdb](https://orchid-project.org/data/databases/sgte-binary/SrB-07Sha.tdb): SRB6_D21, type code %, sha256 `0a3ac53840bde6b1…`

~~~~text
55: PHASE SRB6_D21 % 2 1 6 !
56: CONST SRB6_D21 : SR : B : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.calphad.2006.11.005](https://doi.org/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). https://doi.org/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). https://doi.org/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.

```bibtex
@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}
}
```

---

Derived data CC BY 4.0 ([licence](https://creativecommons.org/licenses/by/4.0/)): cite the ORCHID phase registry and the sources named on the page (TDB assessments, Hallstedt 2025, Materials Project, OQMD). TDB statements are quoted as written; parameter expressions are not reproduced. Field reference: [SCHEMA.md](https://data.orchid-project.org/phases/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt).