Li–O phases

9 phases (tier A 4, liquid 2, gas 2, 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 · Li–O system page · Markdown · field reference

Phases of the Li–O system (9)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
BCC_A2 phase:li-o:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–405 K, x(O) 0–0	2	1
FCC_A1 phase:li-o:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	not stable in 1 calculated diagram(s)	0	1
GAS phase:li-o:gas	gas	gas	stable in 1 of 1 calculated diagram(s): 1611.35–2500 K, x(O) 0–0.99972	4	1
HCP_A3 phase:li-o:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 1 calculated diagram(s)	0	1
ION phase:li-o:ion	liquid	liquid	stable in 1 of 1 calculated diagram(s): 1611.35–2500 K, x(O) 0–0.33333	0	1
LI2O_C1 phase:li-o:li2o-c1	CaF2 · C1 · cF12 · Fm-3m (225)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–778.65 K, x(O) 0.33333–0.33333	13	1
LI2O2 phase:li-o:li2o2		needs_review	stable in 1 of 1 calculated diagram(s): 300–613.65 K, x(O) 0.5–0.5	8	1
LIQUID phase:li-o:liquid	liquid	liquid	not stable in 1 calculated diagram(s)	6	1
O2GAS phase:li-o:o2gas	gas	gas	stable in 1 of 1 calculated diagram(s): 300–778.65 K, x(O) 1–1	0	1

BCC_A2 (Li–O)

Id: phase:li-o:bcc-a2; status assigned
Structure: W · A2 · cI2 · Im-3m (229); type st:a2-w-ci2; tier A: standard phase name; confidence high
Stoichiometry: Li 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–405 K, x(O) 0–0
Literature: 2 values (2 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:li-o:bcc-a2
paper: paper:10.1016/j.calphad.2011.02.003:(Li)
tdb: tdb:LiO-11Cha.tdb:BCC_A2

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

LiO-11Cha.tdb: BCC_A2, type code %B, sha256 6943f8b9e741020b…

51: PHASE BCC_A2 %B 2 1 3 !
52: CONST BCC_A2 : LI : VA : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2011.02.003 Keke Chang, Bengt Hallstedt, Thermodynamic assessment of the Li–O system, Calphad 35, 160-164 (2011).
assessment that models this phase; reports values for this phase
doi:10.1007/bf02667558 J. Sangster, A. D. Pelton, The Li-O (lithium-oxygen) system, JPE 13, 296-299 (1992).
cited as the source of values for this phase

FCC_A1 (Li–O)

Id: phase:li-o:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
Stoichiometry: Li 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:li-o:fcc-a1
tdb: tdb:LiO-11Cha.tdb:FCC_A1

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

LiO-11Cha.tdb: FCC_A1, type code %A, sha256 6943f8b9e741020b…

46: PHASE FCC_A1 %A 2 1 1 !
47: CONST FCC_A1 : LI : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.02.003 Keke Chang, Bengt Hallstedt, Thermodynamic assessment of the Li–O system, Calphad 35, 160-164 (2011).
assessment that models this phase

GAS (Li–O)

Id: phase:li-o:gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1611.35–2500 K, x(O) 0–0.99972
Literature: 4 values (4 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:li-o:gas
paper: paper:10.1016/j.calphad.2011.02.003:Gas
tdb: tdb:LiO-11Cha.tdb:GAS

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

LiO-11Cha.tdb: GAS, type code %, sha256 6943f8b9e741020b…

72: PHASE GAS:G % 1 1 !
73: CONST GAS:G : LI LI2 LI2O LI2O2 O O2 O3 : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2011.02.003 Keke Chang, Bengt Hallstedt, Thermodynamic assessment of the Li–O system, Calphad 35, 160-164 (2011).
assessment that models this phase; reports values for this phase
doi:10.1021/cr60161a001 Leo. Brewer, Thermodynamic Properties of the Oxides and their Vaporization Processes., Chem. Rev. 52, 1-75 (1953).
cited as the source of values for this phase

HCP_A3 (Li–O)

Id: phase:li-o: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: Li 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:li-o:hcp-a3
tdb: tdb:LiO-11Cha.tdb:HCP_A3

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

LiO-11Cha.tdb: HCP_A3, type code %A, sha256 6943f8b9e741020b…

56: PHASE HCP_A3 %A 2 1 0.5 !
57: CONST HCP_A3 : LI : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.02.003 Keke Chang, Bengt Hallstedt, Thermodynamic assessment of the Li–O system, Calphad 35, 160-164 (2011).
assessment that models this phase

ION (Li–O)

Id: phase:li-o:ion; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1611.35–2500 K, x(O) 0–0.33333
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:li-o:ion
tdb: tdb:LiO-11Cha.tdb:ION

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

LiO-11Cha.tdb: ION, type code %, sha256 6943f8b9e741020b…

38: PHASE ION:Y % 2 1 1 !
39: CONST ION:Y : LI+1 : O-2 VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.02.003 Keke Chang, Bengt Hallstedt, Thermodynamic assessment of the Li–O system, Calphad 35, 160-164 (2011).
assessment that models this phase

LI2O_C1 (Li–O)

Id: phase:li-o:li2o-c1; status assigned
Structure: CaF2 · C1 · cF12 · Fm-3m (225); type st:c1-caf2-cf12; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–778.65 K, x(O) 0.33333–0.33333
Literature: 13 values (13 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:li-o:li2o-c1
paper: paper:10.1016/j.calphad.2011.02.003:Li2O
tdb: tdb:LiO-11Cha.tdb:LI2O_C1

TDB models of LI2O_C1 (1): PHASE and CONSTITUENT statements as written

LiO-11Cha.tdb: LI2O_C1, type code %, sha256 6943f8b9e741020b…

61: PHASE LI2O_C1 % 2 2 1 !
62: CONST LI2O_C1 : LI+1 : O-2 : !

Example references (2 of 2; assessments first):

doi:10.1016/j.calphad.2011.02.003 Keke Chang, Bengt Hallstedt, Thermodynamic assessment of the Li–O system, Calphad 35, 160-164 (2011).
assessment that models this phase; reports values for this phase
doi:10.1007/bf02667558 J. Sangster, A. D. Pelton, The Li-O (lithium-oxygen) system, JPE 13, 296-299 (1992).
cited as the source of values for this phase

LI2O2 (Li–O)

Id: phase:li-o:li2o2; status needs_review
No structure assigned. Why: assessment_declared_compound_differs_from_site_ratios; no_structure_token; off_stoichiometric_model
Candidate (dft_mp): P6_3/mmc (194) — on-hull MP Li2O2 at x(O)=0.5000
Candidate (dft_oqmd): P63/mmc (194) — on-hull OQMD Li1 O1 at x(O)=0.5000
Candidate (literature_printed): Li2O2 · hP8 — printed with a label mapped to this phase
Candidate (sgte_mmc2): Li2O2 · hP8 · P6_3/mmc (194) — Hallstedt 2025 mmc2 row for LI2O2: Li2O2
Candidate (tdb_comment): Li2O2 · hP8 · P6_3/mmc — LiO-11Cha.tdb: 'Prototype Li2O2 (hP8, P6_3/mmc)'
Stability: stable in 1 of 1 calculated diagram(s): 300–613.65 K, x(O) 0.5–0.5
Literature: 8 values (8 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:li-o:li2o2
paper: paper:10.1016/j.calphad.2011.02.003:Li2O2
tdb: tdb:LiO-11Cha.tdb:LI2O2

TDB models of LI2O2 (1): PHASE and CONSTITUENT statements as written

LiO-11Cha.tdb: LI2O2, type code %, sha256 6943f8b9e741020b…

66: PHASE LI2O2 % 2 2 1 !
67: CONST LI2O2 : LI+1 : O2-2 : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.02.003 Keke Chang, Bengt Hallstedt, Thermodynamic assessment of the Li–O system, Calphad 35, 160-164 (2011).
assessment that models this phase; reports values for this phase

LIQUID (Li–O)

Id: phase:li-o:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stoichiometry: Li 1.0000
Stability: not stable in 1 calculated diagram(s)
Literature: 6 values (6 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:li-o:liquid
paper: paper:10.1016/j.calphad.2011.02.003:L
tdb: tdb:LiO-11Cha.tdb:LIQUID

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

LiO-11Cha.tdb: LIQUID, type code %, sha256 6943f8b9e741020b…

41: PHASE LIQUID:L % 1 1 !
42: CONST LIQUID:L : LI : !

Example references (3 of 3; assessments first):

doi:10.1016/j.calphad.2011.02.003 Keke Chang, Bengt Hallstedt, Thermodynamic assessment of the Li–O system, Calphad 35, 160-164 (2011).
assessment that models this phase; reports values for this phase
doi:10.1007/bf02667558 J. Sangster, A. D. Pelton, The Li-O (lithium-oxygen) system, JPE 13, 296-299 (1992).
cited as the source of values for this phase
doi:10.1021/cr60161a001 Leo. Brewer, Thermodynamic Properties of the Oxides and their Vaporization Processes., Chem. Rev. 52, 1-75 (1953).
cited as the source of values for this phase

O2GAS (Li–O)

Id: phase:li-o:o2gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–778.65 K, x(O) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:li-o:o2gas
tdb: tdb:LiO-11Cha.tdb:O2GAS

TDB models of O2GAS (1): PHASE and CONSTITUENT statements as written

LiO-11Cha.tdb: O2GAS, type code %, sha256 6943f8b9e741020b…

69: PHASE O2GAS % 1 1 !
70: CONST O2GAS : O2 :!

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.02.003 Keke Chang, Bengt Hallstedt, Thermodynamic assessment of the Li–O system, Calphad 35, 160-164 (2011).
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}
}