Mo–U phases

7 phases (tier A 5, liquid 1, needs_review 1); 5 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 · Mo–U system page · Markdown · field reference

Phases of the Mo–U system (7)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
ORTHORHOMBIC_A20 phase:mo-u:a20-orthorhombic	alpha-U · A20 · oC4 · Cmcm (63)	tier A: standard phase name	stable in 3 of 3 calculated diagram(s): 300–1693.95 K, x(U) 0.9606–1	5	3
BCC_A2 phase:mo-u:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 3 of 3 calculated diagram(s): 300–3999.24 K, x(U) 0–1	13	3
FCC_A1 phase:mo-u:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	not stable in 3 calculated diagram(s)	0	3
HCP_A3 phase:mo-u:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 3 calculated diagram(s)	0	3
LIQUID phase:mo-u:liquid	liquid	liquid	stable in 3 of 3 calculated diagram(s): 1394.29–4000 K, x(U) 0–1	3	3
MOU2_C11B phase:mo-u:mou2-c11b	MoSi2 · C11_b · tI6 · I4/mmm (139)	tier A: standard phase name	stable in 3 of 3 calculated diagram(s): 300–878.42 K, x(U) 0.66667–0.66667	8	3
TETRAGONAL_U phase:mo-u:u-tetragonal		needs_review	stable in 3 of 3 calculated diagram(s): 913.61–2730.86 K, x(U) 0.96883–1	2	3

ORTHORHOMBIC_A20 (Mo–U)

Id: phase:mo-u:a20-orthorhombic; status assigned
Structure: alpha-U · A20 · oC4 · Cmcm (63); type st:a20-alpha-u-oc4; tier A: standard phase name; confidence high
Stability: stable in 3 of 3 calculated diagram(s): 300–1693.95 K, x(U) 0.9606–1
Literature: 5 values (5 accepted) from 2 papers
Interactive: phase registry entry

Names (7): corpus: corpus:phase:mo-u:a20-orthorhombic, corpus:phase:mo-u:orthorhombic-a20
paper: paper:10.1016/j.jnucmat.2010.04.018:ort_A20, paper:10.1016/j.jnucmat.2011.01.043:(α-U)
tdb: tdb:MoU-10Zha.tdb:ORTHORHOMBIC_A20, tdb:MoU-11Ber.tdb:ORTHORHOMBIC_A20, tdb:MoU-18Cor.tdb:ORTHORHOMBIC_A20

TDB models of ORTHORHOMBIC_A20 (3): PHASE and CONSTITUENT statements as written

MoU-10Zha.tdb: ORTHORHOMBIC_A20, type code %, sha256 dd7e1234616d41e7…

45: PHASE ORTHORHOMBIC_A20 % 1 1 !
46: CONST ORTHORHOMBIC_A20 : MO U% : !

MoU-11Ber.tdb: ORTHORHOMBIC_A20, type code %, sha256 2c72abc73554f01c…

43: PHASE ORTHORHOMBIC_A20 % 1 1 !
44: CONST ORTHORHOMBIC_A20 : MO U% : !

MoU-18Cor.tdb: ORTHORHOMBIC_A20, type code %, sha256 767b266713c06987…

43: PHASE ORTHORHOMBIC_A20 % 1 1 !
44: CONST ORTHORHOMBIC_A20 : MO U% : !

Example references (4 of 4; assessments first):

doi:10.1016/j.jnucmat.2010.04.018 X. Zhang, Y.F. Cui, G.L. Xu, W.J. Zhu, H.S. Liu, B.Y. Yin et al., Thermodynamic assessment of the U–Mo–Al system, Journal of Nuclear Materials 402, 15-24 (2010).
assessment that models this phase; reports values for this phase
doi:10.1016/j.jnucmat.2011.01.043 A. Berche, N. Dupin, C. Guéneau, C. Rado, B. Sundman, J.C. Dumas, Calphad thermodynamic description of some binary systems involving U, Journal of Nuclear Materials 411, 131-143 (2011).
assessment that models this phase; reports values for this phase
doi:10.1016/j.calphad.2018.10.002 E.C. Corcoran, J.-L. Fleche, N. Dupin, B. Sundman, C. Gueneau, Calphad, 63, 196-211(2018).
assessment that models this phase
doi:10.1016/0022-3115(60)90028-3 Austin E Dwight, The uranium-molybdenum equilibrium diagram below 900° C, Journal of Nuclear Materials 2, 81-87 (1960).
cited as the source of values for this phase

BCC_A2 (Mo–U)

Id: phase:mo-u: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 3 of 3 calculated diagram(s): 300–3999.24 K, x(U) 0–1
Literature: 13 values (13 accepted) from 2 papers
Interactive: phase registry entry

Names (7): corpus: corpus:phase:mo-u:bcc-a2
paper: paper:10.1016/j.jnucmat.2010.04.018:BCC_A2, paper:10.1016/j.jnucmat.2010.04.018:Mo, paper:10.1016/j.jnucmat.2011.01.043:(γ-U)
tdb: tdb:MoU-10Zha.tdb:BCC_A2, tdb:MoU-11Ber.tdb:BCC_A2, tdb:MoU-18Cor.tdb:BCC_A2

TDB models of BCC_A2 (3): PHASE and CONSTITUENT statements as written

MoU-10Zha.tdb: BCC_A2, type code %B, sha256 dd7e1234616d41e7…

35: PHASE BCC_A2 %B 2 1 3 !
36: CONST BCC_A2 : MO U : VA : !

MoU-11Ber.tdb: BCC_A2, type code %B, sha256 2c72abc73554f01c…

33: PHASE BCC_A2 %B 2 1 3 !
34: CONST BCC_A2 : MO U : VA : !

MoU-18Cor.tdb: BCC_A2, type code %B, sha256 767b266713c06987…

33: PHASE BCC_A2 %B 2 1 3 !
34: CONST BCC_A2 : MO U : VA : !

Example references (5 of 5; assessments first):

doi:10.1016/j.jnucmat.2010.04.018 X. Zhang, Y.F. Cui, G.L. Xu, W.J. Zhu, H.S. Liu, B.Y. Yin et al., Thermodynamic assessment of the U–Mo–Al system, Journal of Nuclear Materials 402, 15-24 (2010).
assessment that models this phase; reports values for this phase
doi:10.1016/j.jnucmat.2011.01.043 A. Berche, N. Dupin, C. Guéneau, C. Rado, B. Sundman, J.C. Dumas, Calphad thermodynamic description of some binary systems involving U, Journal of Nuclear Materials 411, 131-143 (2011).
assessment that models this phase; reports values for this phase
doi:10.1016/j.calphad.2018.10.002 E.C. Corcoran, J.-L. Fleche, N. Dupin, B. Sundman, C. Gueneau, Calphad, 63, 196-211(2018).
assessment that models this phase
doi:10.1016/0022-3115(60)90028-3 Austin E Dwight, The uranium-molybdenum equilibrium diagram below 900° C, Journal of Nuclear Materials 2, 81-87 (1960).
cited as the source of values for this phase
doi:10.1016/0022-3115(77)90078-2 S.P. Garg, R.J. Ackermann, The high temperature phase diagrams for Th-Mo, Th-Re, U-Mo, and U-Re; derived thermodynamic properties of refractory metal solutes in liquid thorium and uranium, Journal of Nuclear Materials 64, 265-274 (1977).
cited as the source of values for this phase

FCC_A1 (Mo–U)

Id: phase:mo-u: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 3 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:mo-u:fcc-a1
tdb: tdb:MoU-10Zha.tdb:FCC_A1, tdb:MoU-11Ber.tdb:FCC_A1, tdb:MoU-18Cor.tdb:FCC_A1

TDB models of FCC_A1 (3): PHASE and CONSTITUENT statements as written

MoU-10Zha.tdb: FCC_A1, type code %A, sha256 dd7e1234616d41e7…

30: PHASE FCC_A1 %A 2 1 1 !
31: CONST FCC_A1 : MO U : VA : !

MoU-11Ber.tdb: FCC_A1, type code %A, sha256 2c72abc73554f01c…

28: PHASE FCC_A1 %A 2 1 1 !
29: CONST FCC_A1 : MO U : VA : !

MoU-18Cor.tdb: FCC_A1, type code %A, sha256 767b266713c06987…

28: PHASE FCC_A1 %A 2 1 1 !
29: CONST FCC_A1 : MO U : VA : !

Example references (3 of 3; assessments first):

doi:10.1016/j.calphad.2018.10.002 E.C. Corcoran, J.-L. Fleche, N. Dupin, B. Sundman, C. Gueneau, Calphad, 63, 196-211(2018).
assessment that models this phase
doi:10.1016/j.jnucmat.2010.04.018 X. Zhang, Y.F. Cui, G.L. Xu, W.J. Zhu, H.S. Liu, B.Y. Yin et al., Thermodynamic assessment of the U–Mo–Al system, Journal of Nuclear Materials 402, 15-24 (2010).
assessment that models this phase
doi:10.1016/j.jnucmat.2011.01.043 A. Berche, N. Dupin, C. Guéneau, C. Rado, B. Sundman, J.C. Dumas, Calphad thermodynamic description of some binary systems involving U, Journal of Nuclear Materials 411, 131-143 (2011).
assessment that models this phase

HCP_A3 (Mo–U)

Id: phase:mo-u: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 3 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:mo-u:hcp-a3
tdb: tdb:MoU-10Zha.tdb:HCP_A3, tdb:MoU-11Ber.tdb:HCP_A3, tdb:MoU-18Cor.tdb:HCP_A3

TDB models of HCP_A3 (3): PHASE and CONSTITUENT statements as written

MoU-10Zha.tdb: HCP_A3, type code %A, sha256 dd7e1234616d41e7…

40: PHASE HCP_A3 %A 2 1 0.5 !
41: CONST HCP_A3 : MO U : VA : !

MoU-11Ber.tdb: HCP_A3, type code %A, sha256 2c72abc73554f01c…

38: PHASE HCP_A3 %A 2 1 0.5 !
39: CONST HCP_A3 : MO U : VA : !

MoU-18Cor.tdb: HCP_A3, type code %A, sha256 767b266713c06987…

38: PHASE HCP_A3 %A 2 1 0.5 !
39: CONST HCP_A3 : MO U : VA : !

Example references (3 of 3; assessments first):

doi:10.1016/j.calphad.2018.10.002 E.C. Corcoran, J.-L. Fleche, N. Dupin, B. Sundman, C. Gueneau, Calphad, 63, 196-211(2018).
assessment that models this phase
doi:10.1016/j.jnucmat.2010.04.018 X. Zhang, Y.F. Cui, G.L. Xu, W.J. Zhu, H.S. Liu, B.Y. Yin et al., Thermodynamic assessment of the U–Mo–Al system, Journal of Nuclear Materials 402, 15-24 (2010).
assessment that models this phase
doi:10.1016/j.jnucmat.2011.01.043 A. Berche, N. Dupin, C. Guéneau, C. Rado, B. Sundman, J.C. Dumas, Calphad thermodynamic description of some binary systems involving U, Journal of Nuclear Materials 411, 131-143 (2011).
assessment that models this phase

LIQUID (Mo–U)

Id: phase:mo-u:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 3 of 3 calculated diagram(s): 1394.29–4000 K, x(U) 0–1
Literature: 3 values (3 accepted) from 2 papers
Interactive: phase registry entry

Names (6): corpus: corpus:phase:mo-u:liquid
paper: paper:10.1016/j.jnucmat.2010.04.018:L, paper:10.1016/j.jnucmat.2011.01.043:L
tdb: tdb:MoU-10Zha.tdb:LIQUID, tdb:MoU-11Ber.tdb:LIQUID, tdb:MoU-18Cor.tdb:LIQUID

TDB models of LIQUID (3): PHASE and CONSTITUENT statements as written

MoU-10Zha.tdb: LIQUID, type code %, sha256 dd7e1234616d41e7…

25: PHASE LIQUID:L % 1 1 !
26: CONST LIQUID:L : MO U : !

MoU-11Ber.tdb: LIQUID, type code %, sha256 2c72abc73554f01c…

23: PHASE LIQUID:L % 1 1 !
24: CONST LIQUID:L : MO U : !

MoU-18Cor.tdb: LIQUID, type code %, sha256 767b266713c06987…

23: PHASE LIQUID:L % 1 1 !
24: CONST LIQUID:L : MO U : !

Example references (4 of 4; assessments first):

doi:10.1016/j.jnucmat.2010.04.018 X. Zhang, Y.F. Cui, G.L. Xu, W.J. Zhu, H.S. Liu, B.Y. Yin et al., Thermodynamic assessment of the U–Mo–Al system, Journal of Nuclear Materials 402, 15-24 (2010).
assessment that models this phase; reports values for this phase
doi:10.1016/j.jnucmat.2011.01.043 A. Berche, N. Dupin, C. Guéneau, C. Rado, B. Sundman, J.C. Dumas, Calphad thermodynamic description of some binary systems involving U, Journal of Nuclear Materials 411, 131-143 (2011).
assessment that models this phase; reports values for this phase
doi:10.1016/j.calphad.2018.10.002 E.C. Corcoran, J.-L. Fleche, N. Dupin, B. Sundman, C. Gueneau, Calphad, 63, 196-211(2018).
assessment that models this phase
doi:10.1016/0022-3115(77)90078-2 S.P. Garg, R.J. Ackermann, The high temperature phase diagrams for Th-Mo, Th-Re, U-Mo, and U-Re; derived thermodynamic properties of refractory metal solutes in liquid thorium and uranium, Journal of Nuclear Materials 64, 265-274 (1977).
cited as the source of values for this phase

MOU2_C11B (Mo–U)

Id: phase:mo-u:mou2-c11b; status assigned
Structure: MoSi2 · C11_b · tI6 · I4/mmm (139); type st:c11-b-mosi2-ti6; tier A: standard phase name; confidence high
Stoichiometry: Mo 0.3333, U 0.6667
Stability: stable in 3 of 3 calculated diagram(s): 300–878.42 K, x(U) 0.66667–0.66667
Literature: 8 values (8 accepted) from 2 papers
Interactive: phase registry entry

Names (6): corpus: corpus:phase:mo-u:mou2-c11b
paper: paper:10.1016/j.jnucmat.2010.04.018:MoU2, paper:10.1016/j.jnucmat.2011.01.043:MoU2
tdb: tdb:MoU-10Zha.tdb:MOU2_C11B, tdb:MoU-11Ber.tdb:MOU2_C11B, tdb:MoU-18Cor.tdb:MOU2_C11B

TDB models of MOU2_C11B (3): PHASE and CONSTITUENT statements as written

MoU-10Zha.tdb: MOU2_C11B, type code %, sha256 dd7e1234616d41e7…

55: PHASE MOU2_C11B % 2 1 2 !
56: CONST MOU2_C11B : MO : U : !

MoU-11Ber.tdb: MOU2_C11B, type code %, sha256 2c72abc73554f01c…

53: PHASE MOU2_C11B % 2 1 2 !
54: CONST MOU2_C11B : MO : U : !

MoU-18Cor.tdb: MOU2_C11B, type code %, sha256 767b266713c06987…

53: PHASE MOU2_C11B % 2 1 2 !
54: CONST MOU2_C11B : MO : U : !

Example references (4 of 4; assessments first):

doi:10.1016/j.jnucmat.2010.04.018 X. Zhang, Y.F. Cui, G.L. Xu, W.J. Zhu, H.S. Liu, B.Y. Yin et al., Thermodynamic assessment of the U–Mo–Al system, Journal of Nuclear Materials 402, 15-24 (2010).
assessment that models this phase; reports values for this phase
doi:10.1016/j.jnucmat.2011.01.043 A. Berche, N. Dupin, C. Guéneau, C. Rado, B. Sundman, J.C. Dumas, Calphad thermodynamic description of some binary systems involving U, Journal of Nuclear Materials 411, 131-143 (2011).
assessment that models this phase; reports values for this phase
doi:10.1016/j.calphad.2018.10.002 E.C. Corcoran, J.-L. Fleche, N. Dupin, B. Sundman, C. Gueneau, Calphad, 63, 196-211(2018).
assessment that models this phase
doi:10.1016/0022-3115(60)90028-3 Austin E Dwight, The uranium-molybdenum equilibrium diagram below 900° C, Journal of Nuclear Materials 2, 81-87 (1960).
cited as the source of values for this phase

TETRAGONAL_U (Mo–U)

Id: phase:mo-u:u-tetragonal; status needs_review
No structure assigned. Why: name_has_descriptive_tokens:TETRAGONAL; no_structure_token
Candidate (sgte_mmc2): beta-U · A_b · tP30 · P4_2/mnm (136) — Hallstedt 2025 mmc2 row for TETRAGONAL_U: beta-U
Candidate (tdb_comment): beta-U · tP30 · P4_2/mnm, SB: A_b — MoU-10Zha.tdb: 'Prototype beta-U (tP30, P4_2/mnm, SB: A_b)'
Candidate (tdb_comment): beta-U · tP30 · P4_2/mnm, SB: A_b — MoU-11Ber.tdb: 'Prototype beta-U (tP30, P4_2/mnm, SB: A_b)'
Candidate (tdb_comment): beta-U · tP30 · P4_2/mnm, SB: A_b — MoU-18Cor.tdb: 'Prototype beta-U (tP30, P4_2/mnm, SB: A_b)'
Stability: stable in 3 of 3 calculated diagram(s): 913.61–2730.86 K, x(U) 0.96883–1
Literature: 2 values (2 accepted) from 1 papers
Interactive: phase registry entry

Names (6): corpus: corpus:phase:mo-u:u-tetragonal, corpus:phase:mo-u:tetragonal-u
paper: paper:10.1016/j.jnucmat.2010.04.018:tetr_U
tdb: tdb:MoU-10Zha.tdb:TETRAGONAL_U, tdb:MoU-11Ber.tdb:TETRAGONAL_U, tdb:MoU-18Cor.tdb:TETRAGONAL_U

TDB models of TETRAGONAL_U (3): PHASE and CONSTITUENT statements as written

MoU-10Zha.tdb: TETRAGONAL_U, type code %, sha256 dd7e1234616d41e7…

50: PHASE TETRAGONAL_U % 1 1 !
51: CONST TETRAGONAL_U : MO U% : !

MoU-11Ber.tdb: TETRAGONAL_U, type code %, sha256 2c72abc73554f01c…

48: PHASE TETRAGONAL_U % 1 1 !
49: CONST TETRAGONAL_U : MO U% : !

MoU-18Cor.tdb: TETRAGONAL_U, type code %, sha256 767b266713c06987…

48: PHASE TETRAGONAL_U % 1 1 !
49: CONST TETRAGONAL_U : MO U% : !

Example references (4 of 4; assessments first):

doi:10.1016/j.jnucmat.2010.04.018 X. Zhang, Y.F. Cui, G.L. Xu, W.J. Zhu, H.S. Liu, B.Y. Yin et al., Thermodynamic assessment of the U–Mo–Al system, Journal of Nuclear Materials 402, 15-24 (2010).
assessment that models this phase; reports values for this phase
doi:10.1016/j.calphad.2018.10.002 E.C. Corcoran, J.-L. Fleche, N. Dupin, B. Sundman, C. Gueneau, Calphad, 63, 196-211(2018).
assessment that models this phase
doi:10.1016/j.jnucmat.2011.01.043 A. Berche, N. Dupin, C. Guéneau, C. Rado, B. Sundman, J.C. Dumas, Calphad thermodynamic description of some binary systems involving U, Journal of Nuclear Materials 411, 131-143 (2011).
assessment that models this phase
doi:10.1016/0022-3115(60)90028-3 Austin E Dwight, The uranium-molybdenum equilibrium diagram below 900° C, Journal of Nuclear Materials 2, 81-87 (1960).
cited as the source of values for 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}
}