Ge–K phases

8 phases (tier A 4, tier B 1, liquid 1, needs_review 2); 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 · Ge–K system page · Markdown · field reference

Phases of the Ge–K system (8)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
DIAMOND_A4 phase:ge-k:a4-diamond	C (diamond) · A4 · cF8 · Fd-3m (227)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1211.4 K, x(K) 0–0	0	1
BCC_A2 phase:ge-k:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–336.53 K, x(K) 1–1	0	1
FCC_A1 phase:ge-k:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	not stable in 1 calculated diagram(s)	0	1
GE4K phase:ge-k:ge4k		needs_review	stable in 1 of 1 calculated diagram(s): 300–1398.17 K, x(K) 0.2–0.2	1	1
GEK phase:ge-k:gek	GeK · cP64 · P-43n (218)	tier B: DFT-supported (unique MP + OQMD match)	stable in 1 of 1 calculated diagram(s): 300–1364.17 K, x(K) 0.5–0.5	2	1
GEK3 phase:ge-k:gek3		needs_review	stable in 1 of 1 calculated diagram(s): 300–1156.87 K, x(K) 0.75–0.75	0	1
HCP_A3 phase:ge-k: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:ge-k:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 333.75–2500 K, x(K) 0–1	0	1

DIAMOND_A4 (Ge–K)

Id: phase:ge-k: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: Ge 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–1211.4 K, x(K) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ge-k:a4-diamond
tdb: tdb:GeK-12Wan.tdb:DIAMOND_A4

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

GeK-12Wan.tdb: DIAMOND_A4, type code %, sha256 d591f02833106db8…

43: PHASE DIAMOND_A4 % 1 1 !
44: CONST DIAMOND_A4 : GE : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2012.01.004 Yaru Wang, Peisheng Wang, Dongdong Zhao, Biao Hu, Yong Du, Honghui Xu et al., Thermodynamic description of the Ge–Na and Ge–K systems using the CALPHAD approach supported by first-principles calculations, Calphad 37, 72-76 (2012).
assessment that models this phase

BCC_A2 (Ge–K)

Id: phase:ge-k:bcc-a2; status assigned
Structure: W · A2 · cI2 · Im-3m (229); type st:a2-w-ci2; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–336.53 K, x(K) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ge-k:bcc-a2
tdb: tdb:GeK-12Wan.tdb:BCC_A2

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

GeK-12Wan.tdb: BCC_A2, type code %B, sha256 d591f02833106db8…

33: PHASE BCC_A2 %B 2 1 3 !
34: CONST BCC_A2 : GE K% : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2012.01.004 Yaru Wang, Peisheng Wang, Dongdong Zhao, Biao Hu, Yong Du, Honghui Xu et al., Thermodynamic description of the Ge–Na and Ge–K systems using the CALPHAD approach supported by first-principles calculations, Calphad 37, 72-76 (2012).
assessment that models this phase

FCC_A1 (Ge–K)

Id: phase:ge-k: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:ge-k:fcc-a1
tdb: tdb:GeK-12Wan.tdb:FCC_A1

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

GeK-12Wan.tdb: FCC_A1, type code %A, sha256 d591f02833106db8…

28: PHASE FCC_A1 %A 2 1 1 !
29: CONST FCC_A1 : GE K : VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2012.01.004 Yaru Wang, Peisheng Wang, Dongdong Zhao, Biao Hu, Yong Du, Honghui Xu et al., Thermodynamic description of the Ge–Na and Ge–K systems using the CALPHAD approach supported by first-principles calculations, Calphad 37, 72-76 (2012).
assessment that models this phase

GE4K (Ge–K)

Id: phase:ge-k:ge4k; status needs_review
No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
Candidate (sgte_mmc2): (Ge4K) — Hallstedt 2025 mmc2 row for GE4K: Ge4K
Stoichiometry: Ge 0.8000, K 0.2000
Stability: stable in 1 of 1 calculated diagram(s): 300–1398.17 K, x(K) 0.2–0.2
Literature: 1 values (1 accepted) from 1 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:ge-k:ge4k
paper: paper:10.1016/j.calphad.2012.01.004:Ge4K
tdb: tdb:GeK-12Wan.tdb:GE4K

TDB models of GE4K (1): PHASE and CONSTITUENT statements as written

GeK-12Wan.tdb: GE4K, type code %, sha256 d591f02833106db8…

48: PHASE GE4K % 2 4 1 !
49: CONST GE4K : GE : K : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2012.01.004 Yaru Wang, Peisheng Wang, Dongdong Zhao, Biao Hu, Yong Du, Honghui Xu et al., Thermodynamic description of the Ge–Na and Ge–K systems using the CALPHAD approach supported by first-principles calculations, Calphad 37, 72-76 (2012).
assessment that models this phase; reports values for this phase

GEK (Ge–K)

Id: phase:ge-k:gek; status assigned
Structure: GeK · cP64 · P-43n (218); type st:gek-cp64; tier B: DFT-supported (unique MP + OQMD match); confidence high
Stoichiometry: Ge 0.5000, K 0.5000
Stability: stable in 1 of 1 calculated diagram(s): 300–1364.17 K, x(K) 0.5–0.5
Literature: 2 values (2 accepted) from 1 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:ge-k:gek
mp: mp:mp-aaaaadeo
oqmd: oqmd:oqmd-649065
paper: paper:10.1016/j.calphad.2012.01.004:GeK
tdb: tdb:GeK-12Wan.tdb:GEK

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

GeK-12Wan.tdb: GEK, type code %, sha256 d591f02833106db8…

53: PHASE GEK % 2 1 1 !
54: CONST GEK : GE : K : !

Example references (3 of 3; assessments first):

doi:10.1016/j.calphad.2012.01.004 Yaru Wang, Peisheng Wang, Dongdong Zhao, Biao Hu, Yong Du, Honghui Xu et al., Thermodynamic description of the Ge–Na and Ge–K systems using the CALPHAD approach supported by first-principles calculations, Calphad 37, 72-76 (2012).
assessment that models this phase; reports values for this phase
doi:10.1002/zaac.19613120310 R. Schäfer, W. Klemm, Das Verhalten der Alkalimetalle zu Halbmetallen. IX. Weitere Beiträge zur Kenntnis der Silicide und Germanide der Alkalimetalle, Zeitschrift anorg allge chemie 312, 214-220 (1961).
cited as the source of values for this phase
doi:10.1002/zaac.19613130108 E. Busmann, Das Verhalten der Alkalimetalle zu Halbmetallen. X. Die Kristallstrukturen von KSi, RbSi, CsSi, KGe, RbGe und CsGe, Zeitschrift anorg allge chemie 313, 90-106 (1961).
cited as the source of values for this phase

GEK3 (Ge–K)

Id: phase:ge-k:gek3; status needs_review
No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
Candidate (sgte_mmc2): (GeK3) — Hallstedt 2025 mmc2 row for GEK3: GeK3
Stoichiometry: Ge 0.2500, K 0.7500
Stability: stable in 1 of 1 calculated diagram(s): 300–1156.87 K, x(K) 0.75–0.75
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ge-k:gek3
tdb: tdb:GeK-12Wan.tdb:GEK3

TDB models of GEK3 (1): PHASE and CONSTITUENT statements as written

GeK-12Wan.tdb: GEK3, type code %, sha256 d591f02833106db8…

58: PHASE GEK3 % 2 1 3 !
59: CONST GEK3 : GE : K : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2012.01.004 Yaru Wang, Peisheng Wang, Dongdong Zhao, Biao Hu, Yong Du, Honghui Xu et al., Thermodynamic description of the Ge–Na and Ge–K systems using the CALPHAD approach supported by first-principles calculations, Calphad 37, 72-76 (2012).
assessment that models this phase

HCP_A3 (Ge–K)

Id: phase:ge-k: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:ge-k:hcp-a3
tdb: tdb:GeK-12Wan.tdb:HCP_A3

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

GeK-12Wan.tdb: HCP_A3, type code %A, sha256 d591f02833106db8…

38: PHASE HCP_A3 %A 2 1 0.5 !
39: CONST HCP_A3 : GE K : VA: !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2012.01.004 Yaru Wang, Peisheng Wang, Dongdong Zhao, Biao Hu, Yong Du, Honghui Xu et al., Thermodynamic description of the Ge–Na and Ge–K systems using the CALPHAD approach supported by first-principles calculations, Calphad 37, 72-76 (2012).
assessment that models this phase

LIQUID (Ge–K)

Id: phase:ge-k:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 333.75–2500 K, x(K) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:ge-k:liquid
tdb: tdb:GeK-12Wan.tdb:LIQUID

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

GeK-12Wan.tdb: LIQUID, type code %, sha256 d591f02833106db8…

23: PHASE LIQUID:L % 1 1 !
24: CONST LIQUID:L : GE K : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2012.01.004 Yaru Wang, Peisheng Wang, Dongdong Zhao, Biao Hu, Yong Du, Honghui Xu et al., Thermodynamic description of the Ge–Na and Ge–K systems using the CALPHAD approach supported by first-principles calculations, Calphad 37, 72-76 (2012).
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}
}