H–Na phases

6 phases (tier A 4, liquid 1, gas 1); 4 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 · Markdown · field reference

Phases of the H–Na system (6)
Phase	Structure	Basis	Stability (calculated)	TDB models
BCC_A2 phase:h-na:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–370.87 K, x(H) 0–0	2
FCC_A1 phase:h-na:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	not stable in 2 calculated diagram(s)	2
GAS phase:h-na:gas	gas	gas	stable in 2 of 2 calculated diagram(s): 300–2500 K, x(H) 0–1	2
HCP_A3 phase:h-na:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 2 calculated diagram(s)	2
LIQUID phase:h-na:liquid	liquid	liquid	stable in 2 of 2 calculated diagram(s): 370.87–1158.44 K, x(H) 0–0.00334	2
NAH_B1 phase:h-na:nah-b1	NaCl · B1 · cF8 · Fm-3m (225)	tier A: standard phase name	stable in 2 of 2 calculated diagram(s): 300–699.54 K, x(H) 0.5–0.5	2

BCC_A2 (H–Na)

Id: phase:h-na: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 2 of 2 calculated diagram(s): 300–370.87 K, x(H) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:h-na:bcc-a2
tdb: tdb:NaH-06Qiu.tdb:BCC_A2, tdb:NaH-93Pel.tdb:BCC_A2

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

NaH-06Qiu.tdb: BCC_A2, type code %B, sha256 450ff68ec5e0694f…

44: PHASE BCC_A2 %B 2 1 3 !
45: CONST BCC_A2 : NA : H VA% : !

NaH-93Pel.tdb: BCC_A2, type code %B, sha256 efda4119d6909c2f…

38: PHASE BCC_A2 %B 2 1 3 !
39: CONST BCC_A2 : NA : VA : !

Example references (2 of 2; assessments first):

doi:10.1515/ijmr-1993-841107 A.D. Pelton, Z. Metallkd., 84, 767-72(1993).
assessment that models this phase
doi:10.3139/ijmr-2006-0136 C. Qiu, S.M. Opalka, G.B. Olson, D.L. Anton, Int. J. Mater. Res., 97, 845-53(2006).
assessment that models this phase

FCC_A1 (H–Na)

Id: phase:h-na:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
Stoichiometry: Na 1.0000
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:h-na:fcc-a1
tdb: tdb:NaH-06Qiu.tdb:FCC_A1, tdb:NaH-93Pel.tdb:FCC_A1

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

NaH-06Qiu.tdb: FCC_A1, type code %A, sha256 450ff68ec5e0694f…

39: PHASE FCC_A1 %A 2 1 1 !
40: CONST FCC_A1 : NA : VA : !

NaH-93Pel.tdb: FCC_A1, type code %A, sha256 efda4119d6909c2f…

33: PHASE FCC_A1 %A 2 1 1 !
34: CONST FCC_A1 : NA : VA : !

Example references (2 of 2; assessments first):

doi:10.1515/ijmr-1993-841107 A.D. Pelton, Z. Metallkd., 84, 767-72(1993).
assessment that models this phase
doi:10.3139/ijmr-2006-0136 C. Qiu, S.M. Opalka, G.B. Olson, D.L. Anton, Int. J. Mater. Res., 97, 845-53(2006).
assessment that models this phase

GAS (H–Na)

Id: phase:h-na:gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 300–2500 K, x(H) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:h-na:gas
tdb: tdb:NaH-06Qiu.tdb:GAS, tdb:NaH-93Pel.tdb:GAS

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

NaH-06Qiu.tdb: GAS, type code %, sha256 450ff68ec5e0694f…

57: PHASE GAS:G % 1 1 !
58: CONST GAS:G : H H2 NA NA2 NAH : !

NaH-93Pel.tdb: GAS, type code %, sha256 efda4119d6909c2f…

51: PHASE GAS:G % 1 1 !
52: CONST GAS:G : H H2 NA NA2 NAH : !

Example references (2 of 2; assessments first):

doi:10.1515/ijmr-1993-841107 A.D. Pelton, Z. Metallkd., 84, 767-72(1993).
assessment that models this phase
doi:10.3139/ijmr-2006-0136 C. Qiu, S.M. Opalka, G.B. Olson, D.L. Anton, Int. J. Mater. Res., 97, 845-53(2006).
assessment that models this phase

HCP_A3 (H–Na)

Id: phase:h-na: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: Na 1.0000
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:h-na:hcp-a3
tdb: tdb:NaH-06Qiu.tdb:HCP_A3, tdb:NaH-93Pel.tdb:HCP_A3

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

NaH-06Qiu.tdb: HCP_A3, type code %A, sha256 450ff68ec5e0694f…

49: PHASE HCP_A3 %A 2 1 0.5 !
50: CONST HCP_A3 : NA : VA : !

NaH-93Pel.tdb: HCP_A3, type code %A, sha256 efda4119d6909c2f…

43: PHASE HCP_A3 %A 2 1 0.5 !
44: CONST HCP_A3 : NA : VA : !

Example references (2 of 2; assessments first):

doi:10.1515/ijmr-1993-841107 A.D. Pelton, Z. Metallkd., 84, 767-72(1993).
assessment that models this phase
doi:10.3139/ijmr-2006-0136 C. Qiu, S.M. Opalka, G.B. Olson, D.L. Anton, Int. J. Mater. Res., 97, 845-53(2006).
assessment that models this phase

LIQUID (H–Na)

Id: phase:h-na:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 370.87–1158.44 K, x(H) 0–0.00334
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:h-na:liquid
tdb: tdb:NaH-06Qiu.tdb:LIQUID, tdb:NaH-93Pel.tdb:LIQUID

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

NaH-06Qiu.tdb: LIQUID, type code %, sha256 450ff68ec5e0694f…

34: PHASE LIQUID:L % 1 1 !
35: CONST LIQUID:L : H NA : !

NaH-93Pel.tdb: LIQUID, type code %, sha256 efda4119d6909c2f…

28: PHASE LIQUID:L % 1 1 !
29: CONST LIQUID:L : NA NAH : !

Example references (2 of 2; assessments first):

doi:10.1515/ijmr-1993-841107 A.D. Pelton, Z. Metallkd., 84, 767-72(1993).
assessment that models this phase
doi:10.3139/ijmr-2006-0136 C. Qiu, S.M. Opalka, G.B. Olson, D.L. Anton, Int. J. Mater. Res., 97, 845-53(2006).
assessment that models this phase

NAH_B1 (H–Na)

Id: phase:h-na:nah-b1; status assigned
Structure: NaCl · B1 · cF8 · Fm-3m (225); type st:b1-nacl-cf8; tier A: standard phase name; confidence high
Caveat: DFT agrees: on-hull mp-aaaabjic and oqmd-642654, space group 225
Stoichiometry: H 0.5000, Na 0.5000
Stability: stable in 2 of 2 calculated diagram(s): 300–699.54 K, x(H) 0.5–0.5
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:h-na:nah-b1
mp: mp:mp-aaaabjic
oqmd: oqmd:oqmd-642654
tdb: tdb:NaH-06Qiu.tdb:NAH_B1, tdb:NaH-93Pel.tdb:NAH_B1

TDB models of NAH_B1 (2): PHASE and CONSTITUENT statements as written

NaH-06Qiu.tdb: NAH_B1, type code %, sha256 450ff68ec5e0694f…

54: PHASE NAH_B1 % 2 1 1 !
55: CONST NAH_B1 : NA : H : !

NaH-93Pel.tdb: NAH_B1, type code %, sha256 efda4119d6909c2f…

48: PHASE NAH_B1 % 2 1 1 !
49: CONST NAH_B1 : NA : H : !

Example references (2 of 2; assessments first):

doi:10.1515/ijmr-1993-841107 A.D. Pelton, Z. Metallkd., 84, 767-72(1993).
assessment that models this phase
doi:10.3139/ijmr-2006-0136 C. Qiu, S.M. Opalka, G.B. Olson, D.L. Anton, Int. J. Mater. Res., 97, 845-53(2006).
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}
}