B–Mg phases
10 phases (tier A 3, tier B 1, tier C 3, liquid 1, gas 1, needs_review 1); 8 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 · B–Mg system page · Markdown · field reference
| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---|---|
| BETA_RHOMBO_B phase:b-mg:b-beta-rhombo | needs_review | stable in 2 of 2 calculated diagram(s): 300–2351.38 K, x(B) 1–1 | 0 | 2 | |
| BCC_A2 phase:b-mg:bcc-a2 | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | not stable in 2 calculated diagram(s) | 0 | 2 |
| MB2_C32 phase:b-mg:c32-mb2 | AlB2 · C32 · hP3 · P6/mmm (191) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 2 of 2 calculated diagram(s): 300–1979.09 K, x(B) 0.66667–0.66667 | 27 | 2 |
| FCC_A1 phase:b-mg:fcc-a1 | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | not stable in 2 calculated diagram(s) | 0 | 2 |
| GAS phase:b-mg:gas | gas | gas | stable in 2 of 2 calculated diagram(s): 1367.63–4000 K, x(B) 0–0.52475 | 4 | 2 |
| HCP_A3 phase:b-mg:hcp-a3 | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 300–1468 K, x(B) 0–0 | 1 | 2 |
| LIQUID phase:b-mg:liquid | liquid | liquid | stable in 2 of 2 calculated diagram(s): 922.85–4000 K, x(B) 0–1 | 4 | 2 |
| MGB20 phase:b-mg:mgb20 | ScB28 · hR119 · R-3m (166) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–2465.49 K, x(B) 0.95238–0.95238 | 12 | 1 |
| MGB4 phase:b-mg:mgb4 | MgB4 · oP20 · Pnma (62) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 2 of 2 calculated diagram(s): 300–2281.82 K, x(B) 0.8–0.8 | 27 | 2 |
| MGB7 phase:b-mg:mgb7 | MgB7 · oI64 · Imma (74) | tier B: DFT-supported (unique MP + OQMD match) | stable in 2 of 2 calculated diagram(s): 300–2424.01 K, x(B) 0.875–0.875 | 18 | 2 |
BETA_RHOMBO_B (B–Mg)
- Id:
phase:b-mg:b-beta-rhombo; statusneeds_review - No structure assigned. Why: name_has_descriptive_tokens:RHOMBO; no_structure_token
- Candidate (sgte_mmc2): beta-B · hR105 · R-3m (166) — Hallstedt 2025 mmc2 row for BETA_RHOMBO_B: beta-B
- Candidate (tdb_comment): beta-B · hR105 · R-3m — MgB-01Liu-LB.tdb: 'Prototype beta-B (hR105, R-3m)'
- Candidate (tdb_comment): beta-B · hR105 · R-3m — MgB-05Bal.tdb: 'Prototype beta-B (hR105, R-3m)'
- Stoichiometry: B 1.0000
- Stability: stable in 2 of 2 calculated diagram(s): 300–2351.38 K, x(B) 1–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: phase registry entry
Names (4): corpus: corpus:phase:b-mg:b-beta-rhombo, corpus:phase:b-mg:beta-rhombo-b
tdb: tdb:MgB-01Liu-LB.tdb:BETA_RHOMBO_B, tdb:MgB-05Bal.tdb:BETA_RHOMBO_B
TDB models of BETA_RHOMBO_B (2): PHASE and CONSTITUENT statements as written
MgB-01Liu-LB.tdb: BETA_RHOMBO_B, type code %, sha256 8309e62bcb5a44e3…
47: PHASE BETA_RHOMBO_B % 1 1 ! 48: CONST BETA_RHOMBO_B : B : !
MgB-05Bal.tdb: BETA_RHOMBO_B, type code %, sha256 560f62e9d31af938…
49: PHASE BETA_RHOMBO_B % 1 1 ! 50: CONST BETA_RHOMBO_B : B : !
Example references (2 of 2; assessments first):
- doi:10.1016/j.jpcs.2004.06.063 G. Balducci, S. Brutti, A. Ciccioli, G. Gigli, P. Manfrinetti, A. Palenzona et al., Thermodynamics of the intermediate phases in the Mg–B system, Journal of Physics and Chemistry of Solids 66, 292-297 (2005).
assessment that models this phase - doi:10.1016/S0364-5916(01)00050-5 Z.-K. Liu, Y. Zhong, D.G. Schlom, X.X. Xi, Q. Li, Calphad, 25, 299-303(2001).
assessment that models this phase
BCC_A2 (B–Mg)
- Id:
phase:b-mg:bcc-a2; statusassigned - Structure: W · A2 · cI2 · Im-3m (229); type
st:a2-w-ci2; tier A: standard phase name; confidence high - Stoichiometry: Mg 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:b-mg:bcc-a2
tdb: tdb:MgB-01Liu-LB.tdb:BCC_A2, tdb:MgB-05Bal.tdb:BCC_A2
TDB models of BCC_A2 (2): PHASE and CONSTITUENT statements as written
MgB-01Liu-LB.tdb: BCC_A2, type code %B, sha256 8309e62bcb5a44e3…
37: PHASE BCC_A2 %B 2 1 3 ! 38: CONST BCC_A2 : MG : VA : !
MgB-05Bal.tdb: BCC_A2, type code %B, sha256 560f62e9d31af938…
39: PHASE BCC_A2 %B 2 1 3 ! 40: CONST BCC_A2 : MG : VA : !
Example references (2 of 2; assessments first):
- doi:10.1016/j.jpcs.2004.06.063 G. Balducci, S. Brutti, A. Ciccioli, G. Gigli, P. Manfrinetti, A. Palenzona et al., Thermodynamics of the intermediate phases in the Mg–B system, Journal of Physics and Chemistry of Solids 66, 292-297 (2005).
assessment that models this phase - doi:10.1016/S0364-5916(01)00050-5 Z.-K. Liu, Y. Zhong, D.G. Schlom, X.X. Xi, Q. Li, Calphad, 25, 299-303(2001).
assessment that models this phase
MB2_C32 (B–Mg)
- Id:
phase:b-mg:c32-mb2; statusassigned - Structure: AlB2 · C32 · hP3 · P6/mmm (191); type
st:c32-alb2-hp3; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated - Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) doi:10.1016/j.calphad.2025.102833
- Caveat: DFT agrees: on-hull mp-aaaaabdj and oqmd-98302, space group 191
- Caveat: not certain from the name or DFT alone (unrecognised_name_tokens:MB2); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: B 0.6667, Mg 0.3333
- Stability: stable in 2 of 2 calculated diagram(s): 300–1979.09 K, x(B) 0.66667–0.66667
- Literature: 27 values (27 accepted) from 2 papers
- Interactive: phase registry entry
Names (8): corpus: corpus:phase:b-mg:c32-mb2, corpus:phase:b-mg:mb2-c32
mp: mp:mp-aaaaabdj
oqmd: oqmd:oqmd-98302
paper: paper:10.1016/j.jpcs.2004.06.063:MgB2, paper:10.1016/s0364-5916(01)00050-5:MgB2
tdb: tdb:MgB-01Liu-LB.tdb:MB2_C32, tdb:MgB-05Bal.tdb:MB2_C32
TDB models of MB2_C32 (2): PHASE and CONSTITUENT statements as written
MgB-01Liu-LB.tdb: MB2_C32, type code %, sha256 8309e62bcb5a44e3…
52: PHASE MB2_C32 % 2 1 2 ! 53: CONST MB2_C32 : MG : B : !
MgB-05Bal.tdb: MB2_C32, type code %, sha256 560f62e9d31af938…
54: PHASE MB2_C32 % 2 1 2 ! 55: CONST MB2_C32 : MG : B : !
Example references (3 of 3; assessments first):
- doi:10.1016/j.jpcs.2004.06.063 G. Balducci, S. Brutti, A. Ciccioli, G. Gigli, P. Manfrinetti, A. Palenzona et al., Thermodynamics of the intermediate phases in the Mg–B system, Journal of Physics and Chemistry of Solids 66, 292-297 (2005).
assessment that models this phase; reports values for this phase - doi:10.1016/S0364-5916(01)00050-5 Z.-K. Liu, Y. Zhong, D.G. Schlom, X.X. Xi, Q. Li, Calphad, 25, 299-303(2001).
assessment that models this phase; reports values for this phase - doi:10.1016/0364-5916(85)90021-5 Bo Sundman, Bo Jansson, Jan-Olof Andersson, The Thermo-Calc databank system, Calphad 9, 153-190 (1985).
cited as the source of values for this phase
FCC_A1 (B–Mg)
- Id:
phase:b-mg:fcc-a1; statusassigned - Structure: Cu · A1 · cF4 · Fm-3m (225); type
st:a1-cu-cf4; tier A: standard phase name; confidence high - Stoichiometry: Mg 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:b-mg:fcc-a1
tdb: tdb:MgB-01Liu-LB.tdb:FCC_A1, tdb:MgB-05Bal.tdb:FCC_A1
TDB models of FCC_A1 (2): PHASE and CONSTITUENT statements as written
MgB-01Liu-LB.tdb: FCC_A1, type code %A, sha256 8309e62bcb5a44e3…
32: PHASE FCC_A1 %A 2 1 1 ! 33: CONST FCC_A1 : MG : VA : !
MgB-05Bal.tdb: FCC_A1, type code %A, sha256 560f62e9d31af938…
34: PHASE FCC_A1 %A 2 1 1 ! 35: CONST FCC_A1 : MG : VA : !
Example references (2 of 2; assessments first):
- doi:10.1016/j.jpcs.2004.06.063 G. Balducci, S. Brutti, A. Ciccioli, G. Gigli, P. Manfrinetti, A. Palenzona et al., Thermodynamics of the intermediate phases in the Mg–B system, Journal of Physics and Chemistry of Solids 66, 292-297 (2005).
assessment that models this phase - doi:10.1016/S0364-5916(01)00050-5 Z.-K. Liu, Y. Zhong, D.G. Schlom, X.X. Xi, Q. Li, Calphad, 25, 299-303(2001).
assessment that models this phase
GAS (B–Mg)
- Id:
phase:b-mg:gas; statusassigned - Structure: gas; type
st:gas; gas; confidence high - Stability: stable in 2 of 2 calculated diagram(s): 1367.63–4000 K, x(B) 0–0.52475
- Literature: 4 values (4 accepted) from 1 papers
- Interactive: phase registry entry
Names (4): corpus: corpus:phase:b-mg:gas
paper: paper:10.1016/s0364-5916(01)00050-5:gas
tdb: tdb:MgB-01Liu-LB.tdb:GAS, tdb:MgB-05Bal.tdb:GAS
TDB models of GAS (2): PHASE and CONSTITUENT statements as written
MgB-01Liu-LB.tdb: GAS, type code %, sha256 8309e62bcb5a44e3…
65: PHASE GAS:G % 1 1 ! 66: CONST GAS:G : B B2 MG MG2 : !
MgB-05Bal.tdb: GAS, type code %, sha256 560f62e9d31af938…
72: PHASE GAS:G % 1 1 ! 73: CONST GAS:G : B B2 MG MG2 : !
Example references (2 of 2; assessments first):
- doi:10.1016/S0364-5916(01)00050-5 Z.-K. Liu, Y. Zhong, D.G. Schlom, X.X. Xi, Q. Li, Calphad, 25, 299-303(2001).
assessment that models this phase; reports values for this phase - doi:10.1016/j.jpcs.2004.06.063 G. Balducci, S. Brutti, A. Ciccioli, G. Gigli, P. Manfrinetti, A. Palenzona et al., Thermodynamics of the intermediate phases in the Mg–B system, Journal of Physics and Chemistry of Solids 66, 292-297 (2005).
assessment that models this phase
HCP_A3 (B–Mg)
- Id:
phase:b-mg:hcp-a3; statusassigned - Structure: Mg · A3 · hP2 · P6_3/mmc (194); type
st:a3-mg-hp2; tier A: standard phase name; confidence high - Stoichiometry: Mg 1.0000
- Stability: stable in 2 of 2 calculated diagram(s): 300–1468 K, x(B) 0–0
- Literature: 1 values (1 accepted) from 1 papers
- Interactive: phase registry entry
Names (4): corpus: corpus:phase:b-mg:hcp-a3
paper: paper:10.1016/s0364-5916(01)00050-5:hcp
tdb: tdb:MgB-01Liu-LB.tdb:HCP_A3, tdb:MgB-05Bal.tdb:HCP_A3
TDB models of HCP_A3 (2): PHASE and CONSTITUENT statements as written
MgB-01Liu-LB.tdb: HCP_A3, type code %A, sha256 8309e62bcb5a44e3…
42: PHASE HCP_A3 %A 2 1 0.5 ! 43: CONST HCP_A3 : MG% : VA : !
MgB-05Bal.tdb: HCP_A3, type code %A, sha256 560f62e9d31af938…
44: PHASE HCP_A3 %A 2 1 0.5 ! 45: CONST HCP_A3 : MG% : VA : !
Example references (2 of 2; assessments first):
- doi:10.1016/S0364-5916(01)00050-5 Z.-K. Liu, Y. Zhong, D.G. Schlom, X.X. Xi, Q. Li, Calphad, 25, 299-303(2001).
assessment that models this phase; reports values for this phase - doi:10.1016/j.jpcs.2004.06.063 G. Balducci, S. Brutti, A. Ciccioli, G. Gigli, P. Manfrinetti, A. Palenzona et al., Thermodynamics of the intermediate phases in the Mg–B system, Journal of Physics and Chemistry of Solids 66, 292-297 (2005).
assessment that models this phase
LIQUID (B–Mg)
- Id:
phase:b-mg:liquid; statusassigned - Structure: liquid; type
st:liquid; liquid; confidence high - Stability: stable in 2 of 2 calculated diagram(s): 922.85–4000 K, x(B) 0–1
- Literature: 4 values (4 accepted) from 1 papers
- Interactive: phase registry entry
Names (4): corpus: corpus:phase:b-mg:liquid
paper: paper:10.1016/s0364-5916(01)00050-5:liq
tdb: tdb:MgB-01Liu-LB.tdb:LIQUID, tdb:MgB-05Bal.tdb:LIQUID
TDB models of LIQUID (2): PHASE and CONSTITUENT statements as written
MgB-01Liu-LB.tdb: LIQUID, type code %, sha256 8309e62bcb5a44e3…
27: PHASE LIQUID:L % 1 1 ! 28: CONST LIQUID:L : B MG : !
MgB-05Bal.tdb: LIQUID, type code %, sha256 560f62e9d31af938…
29: PHASE LIQUID:L % 1 1 ! 30: CONST LIQUID:L : B MG : !
Example references (2 of 2; assessments first):
- doi:10.1016/S0364-5916(01)00050-5 Z.-K. Liu, Y. Zhong, D.G. Schlom, X.X. Xi, Q. Li, Calphad, 25, 299-303(2001).
assessment that models this phase; reports values for this phase - doi:10.1016/j.jpcs.2004.06.063 G. Balducci, S. Brutti, A. Ciccioli, G. Gigli, P. Manfrinetti, A. Palenzona et al., Thermodynamics of the intermediate phases in the Mg–B system, Journal of Physics and Chemistry of Solids 66, 292-297 (2005).
assessment that models this phase
MGB20 (B–Mg)
- Id:
phase:b-mg:mgb20; statusassigned - Structure: ScB28 · hR119 · R-3m (166); type
st:scb28-hr119; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated - Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) doi:10.1016/j.calphad.2025.102833
- Caveat: not certain from the name or DFT alone (no_on_hull_entry_in_both, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: B 0.9524, Mg 0.0476
- Stability: stable in 1 of 1 calculated diagram(s): 300–2465.49 K, x(B) 0.95238–0.95238
- Literature: 12 values (12 accepted) from 1 papers
- Interactive: phase registry entry
Names (3): corpus: corpus:phase:b-mg:mgb20
paper: paper:10.1016/j.jpcs.2004.06.063:MgB20
tdb: tdb:MgB-05Bal.tdb:MGB20
TDB models of MGB20 (1): PHASE and CONSTITUENT statements as written
MgB-05Bal.tdb: MGB20, type code %, sha256 560f62e9d31af938…
69: PHASE MGB20 % 2 1 20 ! 70: CONST MGB20 : MG : B : !
Example references (1 of 1; assessments first):
- doi:10.1016/j.jpcs.2004.06.063 G. Balducci, S. Brutti, A. Ciccioli, G. Gigli, P. Manfrinetti, A. Palenzona et al., Thermodynamics of the intermediate phases in the Mg–B system, Journal of Physics and Chemistry of Solids 66, 292-297 (2005).
assessment that models this phase; reports values for this phase
MGB4 (B–Mg)
- Id:
phase:b-mg:mgb4; statusassigned - Structure: MgB4 · oP20 · Pnma (62); type
st:mgb4-op20; tier C: assessor-stated (Hallstedt 2025 crystallographic table); confidence assessor-stated - Structure source: B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, supplementary crystallographic table (mmc2) doi:10.1016/j.calphad.2025.102833
- Caveat: not certain from the name or DFT alone (dft_space_group_62_matches_2_structure_types, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: B 0.8000, Mg 0.2000
- Stability: stable in 2 of 2 calculated diagram(s): 300–2281.82 K, x(B) 0.8–0.8
- Literature: 27 values (27 accepted) from 2 papers
- Interactive: phase registry entry
Names (5): corpus: corpus:phase:b-mg:mgb4
paper: paper:10.1016/j.jpcs.2004.06.063:MgB4, paper:10.1016/s0364-5916(01)00050-5:MgB4
tdb: tdb:MgB-01Liu-LB.tdb:MGB4, tdb:MgB-05Bal.tdb:MGB4
TDB models of MGB4 (2): PHASE and CONSTITUENT statements as written
MgB-01Liu-LB.tdb: MGB4, type code %, sha256 8309e62bcb5a44e3…
57: PHASE MGB4 % 2 1 4 ! 58: CONST MGB4 : MG : B : !
MgB-05Bal.tdb: MGB4, type code %, sha256 560f62e9d31af938…
59: PHASE MGB4 % 2 1 4 ! 60: CONST MGB4 : MG : B : !
Example references (5 of 5; assessments first):
- doi:10.1016/j.jpcs.2004.06.063 G. Balducci, S. Brutti, A. Ciccioli, G. Gigli, P. Manfrinetti, A. Palenzona et al., Thermodynamics of the intermediate phases in the Mg–B system, Journal of Physics and Chemistry of Solids 66, 292-297 (2005).
assessment that models this phase; reports values for this phase - doi:10.1016/S0364-5916(01)00050-5 Z.-K. Liu, Y. Zhong, D.G. Schlom, X.X. Xi, Q. Li, Calphad, 25, 299-303(2001).
assessment that models this phase; reports values for this phase - doi:10.1007/bf02057252 R. Pan, Manika Varma Nair, B. Wunderlich, On theC p toC v conversion of solid linear macromolecules II, Journal of Thermal Analysis 35, 955-966 (1989).
cited as the source of values for this phase - doi:10.1016/0364-5916(85)90021-5 Bo Sundman, Bo Jansson, Jan-Olof Andersson, The Thermo-Calc databank system, Calphad 9, 153-190 (1985).
cited as the source of values for this phase - doi:10.1023/a:1010188110516 M. Pyda, M. Bartkowiak, B. Wunderlich, Computation of Heat Capacities of Solids Using a General Tarasov Equation, Journal of Thermal Analysis and Calorimetry 52, 631-656 (1998).
cited as the source of values for this phase
MGB7 (B–Mg)
- Id:
phase:b-mg:mgb7; statusassigned - Structure: MgB7 · oI64 · Imma (74); type
st:mgb7-oi64; tier B: DFT-supported (unique MP + OQMD match); confidence high - Stoichiometry: B 0.8750, Mg 0.1250
- Stability: stable in 2 of 2 calculated diagram(s): 300–2424.01 K, x(B) 0.875–0.875
- Literature: 18 values (18 accepted) from 2 papers
- Interactive: phase registry entry
Names (7): corpus: corpus:phase:b-mg:mgb7
mp: mp:mp-aaacdrdz
oqmd: oqmd:oqmd-23820
paper: paper:10.1016/j.jpcs.2004.06.063:MgB7, paper:10.1016/s0364-5916(01)00050-5:MgB7
tdb: tdb:MgB-01Liu-LB.tdb:MGB7, tdb:MgB-05Bal.tdb:MGB7
TDB models of MGB7 (2): PHASE and CONSTITUENT statements as written
MgB-01Liu-LB.tdb: MGB7, type code %, sha256 8309e62bcb5a44e3…
62: PHASE MGB7 % 2 1 7 ! 63: CONST MGB7 : MG : B : !
MgB-05Bal.tdb: MGB7, type code %, sha256 560f62e9d31af938…
64: PHASE MGB7 % 2 1 7 ! 65: CONST MGB7 : MG : B : !
Example references (4 of 4; assessments first):
- doi:10.1016/j.jpcs.2004.06.063 G. Balducci, S. Brutti, A. Ciccioli, G. Gigli, P. Manfrinetti, A. Palenzona et al., Thermodynamics of the intermediate phases in the Mg–B system, Journal of Physics and Chemistry of Solids 66, 292-297 (2005).
assessment that models this phase; reports values for this phase - doi:10.1016/S0364-5916(01)00050-5 Z.-K. Liu, Y. Zhong, D.G. Schlom, X.X. Xi, Q. Li, Calphad, 25, 299-303(2001).
assessment that models this phase; reports values for this phase - doi:10.1007/bf02057252 R. Pan, Manika Varma Nair, B. Wunderlich, On theC p toC v conversion of solid linear macromolecules II, Journal of Thermal Analysis 35, 955-966 (1989).
cited as the source of values for this phase - doi:10.1023/a:1010188110516 M. Pyda, M. Bartkowiak, B. Wunderlich, Computation of Heat Capacities of Solids Using a General Tarasov Equation, Journal of Thermal Analysis and Calorimetry 52, 631-656 (1998).
cited as the source of values for this phase