Al–Np phases

8 phases (tier A 7, liquid 1); 7 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 · Al–Np system page · Markdown · field reference

Phases of the Al–Np system (8)
Phase	Structure	Basis	Stability (calculated)	TDB models
AL2NP_C15 phase:al-np:al2np-c15	Cu2Mg · C15 · cF24 · Fd-3m (227)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1849.41 K, x(Np) 0.33333–0.33333	1
AL3NP_L12 phase:al-np:al3np-l12	AuCu3 · L1_2 · cP4 · Pm-3m (221)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1610 K, x(Np) 0.25–0.25	1
AL4NP_D1B phase:al-np:al4np-d1b	Al4U · D1_b · oI20 · Imma (74)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1085.08 K, x(Np) 0.2–0.2	1
BCC_A2 phase:al-np:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 654.68–917.21 K, x(Np) 0.99824–1	1
FCC_A1 phase:al-np:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–933.47 K, x(Np) 0–0	1
HCP_A3 phase:al-np:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 1 calculated diagram(s)	1
LIQUID phase:al-np:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 916.84–2500 K, x(Np) 0–1	1
ORTHO_AC phase:al-np:ortho-ac	alpha-Np · A_c · oP8 · Pnma (62)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–654.68 K, x(Np) 1–1	1

AL2NP_C15 (Al–Np)

Id: phase:al-np:al2np-c15; status assigned
Structure: Cu2Mg · C15 · cF24 · Fd-3m (227); type st:c15-cu2mg-cf24; tier A: standard phase name; confidence high
Stoichiometry: Al 0.6667, Np 0.3333
Stability: stable in 1 of 1 calculated diagram(s): 300–1849.41 K, x(Np) 0.33333–0.33333
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:al-np:al2np-c15
tdb: tdb:AlNp-10Sed.tdb:AL2NP_C15

TDB models of AL2NP_C15 (1): PHASE and CONSTITUENT statements as written

AlNp-10Sed.tdb: AL2NP_C15, type code %, sha256 34943cc0a95229e5…

63: PHASE AL2NP_C15 % 2 2 1 !
64: CONST AL2NP_C15 : AL : NP : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jnucmat.2009.11.023 D. Sedmidubský, R.J.M. Konings, P. Souček, Ab-initio calculations and phase diagram assessments of An–Al systems (An= U, Np, Pu), Journal of Nuclear Materials 397, 1-7 (2010).
assessment that models this phase

AL3NP_L12 (Al–Np)

Id: phase:al-np:al3np-l12; status assigned
Structure: AuCu3 · L1_2 · cP4 · Pm-3m (221); type st:l1-2-aucu3-cp4; tier A: standard phase name; confidence high
Stoichiometry: Al 0.7500, Np 0.2500
Stability: stable in 1 of 1 calculated diagram(s): 300–1610 K, x(Np) 0.25–0.25
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:al-np:al3np-l12
tdb: tdb:AlNp-10Sed.tdb:AL3NP_L12

TDB models of AL3NP_L12 (1): PHASE and CONSTITUENT statements as written

AlNp-10Sed.tdb: AL3NP_L12, type code %, sha256 34943cc0a95229e5…

58: PHASE AL3NP_L12 % 2 3 1 !
59: CONST AL3NP_L12 : AL : NP : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jnucmat.2009.11.023 D. Sedmidubský, R.J.M. Konings, P. Souček, Ab-initio calculations and phase diagram assessments of An–Al systems (An= U, Np, Pu), Journal of Nuclear Materials 397, 1-7 (2010).
assessment that models this phase

AL4NP_D1B (Al–Np)

Id: phase:al-np:al4np-d1b; status assigned
Structure: Al4U · D1_b · oI20 · Imma (74); type st:d1-b-al4u-oi20; tier A: standard phase name; confidence high
Caveat: DFT agrees: on-hull mp-aaaaaylk and oqmd-20884, space group 74
Stoichiometry: Al 0.8000, Np 0.2000
Stability: stable in 1 of 1 calculated diagram(s): 300–1085.08 K, x(Np) 0.2–0.2
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:al-np:al4np-d1b
mp: mp:mp-aaaaaylk
oqmd: oqmd:oqmd-20884
tdb: tdb:AlNp-10Sed.tdb:AL4NP_D1B

TDB models of AL4NP_D1B (1): PHASE and CONSTITUENT statements as written

AlNp-10Sed.tdb: AL4NP_D1B, type code %, sha256 34943cc0a95229e5…

53: PHASE AL4NP_D1B % 2 4 1 !
54: CONST AL4NP_D1B : AL : NP : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jnucmat.2009.11.023 D. Sedmidubský, R.J.M. Konings, P. Souček, Ab-initio calculations and phase diagram assessments of An–Al systems (An= U, Np, Pu), Journal of Nuclear Materials 397, 1-7 (2010).
assessment that models this phase

BCC_A2 (Al–Np)

Id: phase:al-np: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): 654.68–917.21 K, x(Np) 0.99824–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:al-np:bcc-a2
tdb: tdb:AlNp-10Sed.tdb:BCC_A2

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

AlNp-10Sed.tdb: BCC_A2, type code %B, sha256 34943cc0a95229e5…

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

Example references (1 of 1; assessments first):

doi:10.1016/j.jnucmat.2009.11.023 D. Sedmidubský, R.J.M. Konings, P. Souček, Ab-initio calculations and phase diagram assessments of An–Al systems (An= U, Np, Pu), Journal of Nuclear Materials 397, 1-7 (2010).
assessment that models this phase

FCC_A1 (Al–Np)

Id: phase:al-np:fcc-a1; status assigned
Structure: Cu · A1 · cF4 · Fm-3m (225); type st:a1-cu-cf4; tier A: standard phase name; confidence high
Stoichiometry: Al 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–933.47 K, x(Np) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:al-np:fcc-a1
tdb: tdb:AlNp-10Sed.tdb:FCC_A1

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

AlNp-10Sed.tdb: FCC_A1, type code %A, sha256 34943cc0a95229e5…

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

Example references (1 of 1; assessments first):

doi:10.1016/j.jnucmat.2009.11.023 D. Sedmidubský, R.J.M. Konings, P. Souček, Ab-initio calculations and phase diagram assessments of An–Al systems (An= U, Np, Pu), Journal of Nuclear Materials 397, 1-7 (2010).
assessment that models this phase

HCP_A3 (Al–Np)

Id: phase:al-np: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: Al 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:al-np:hcp-a3
tdb: tdb:AlNp-10Sed.tdb:HCP_A3

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

AlNp-10Sed.tdb: HCP_A3, type code %A, sha256 34943cc0a95229e5…

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

Example references (1 of 1; assessments first):

doi:10.1016/j.jnucmat.2009.11.023 D. Sedmidubský, R.J.M. Konings, P. Souček, Ab-initio calculations and phase diagram assessments of An–Al systems (An= U, Np, Pu), Journal of Nuclear Materials 397, 1-7 (2010).
assessment that models this phase

LIQUID (Al–Np)

Id: phase:al-np:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 916.84–2500 K, x(Np) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:al-np:liquid
tdb: tdb:AlNp-10Sed.tdb:LIQUID

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

AlNp-10Sed.tdb: LIQUID, type code %, sha256 34943cc0a95229e5…

28: PHASE LIQUID:L % 1 1 !
29: CONST LIQUID:L : AL AL2NP NP : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jnucmat.2009.11.023 D. Sedmidubský, R.J.M. Konings, P. Souček, Ab-initio calculations and phase diagram assessments of An–Al systems (An= U, Np, Pu), Journal of Nuclear Materials 397, 1-7 (2010).
assessment that models this phase

ORTHO_AC (Al–Np)

Id: phase:al-np:ortho-ac; status assigned
Structure: alpha-Np · A_c · oP8 · Pnma (62); type st:a-c-alpha-np-op8; tier A: standard phase name; confidence high
Stoichiometry: Np 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–654.68 K, x(Np) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:al-np:ortho-ac
tdb: tdb:AlNp-10Sed.tdb:ORTHO_AC

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

AlNp-10Sed.tdb: ORTHO_AC, type code %, sha256 34943cc0a95229e5…

48: PHASE ORTHO_AC % 1 1 !
49: CONST ORTHO_AC : NP : !

Example references (1 of 1; assessments first):

doi:10.1016/j.jnucmat.2009.11.023 D. Sedmidubský, R.J.M. Konings, P. Souček, Ab-initio calculations and phase diagram assessments of An–Al systems (An= U, Np, Pu), Journal of Nuclear Materials 397, 1-7 (2010).
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}
}