# Sn–U phases > Sn–U system: 15 phases (tier A 7, tier C 6, liquid 1, needs_review 1); 12 stable in a calculated diagram in the ORCHID phase registry, with names, structure type when the stored evidence supports an assignment under the stated tier rules, calculated stability, verbatim TDB PHASE/CONSTITUENT statements and example references. HTML: https://data.orchid-project.org/phases/pages/SN-U.html · Markdown: https://data.orchid-project.org/phases/pages/SN-U.md 15 phases (tier A 7, tier C 6, liquid 1, needs_review 1); 12 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](https://orchid-project.org/phases/?q=SN-U) · [full JSON](https://data.orchid-project.org/phases/systems/SN-U.json) · [Sn–U system page](https://data.orchid-project.org/systems/SN-U.html) · [Markdown](https://data.orchid-project.org/phases/pages/SN-U.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md) Table: Phases of the Sn–U system (15) | Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models | |---|---|---|---|---:|---:| | [ORTHORHOMBIC_A20](#phase-sn-u-a20-orthorhombic); _phase:sn-u:a20-orthorhombic_ | alpha-U · A20 · oC4 · Cmcm (63) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 300–942.02 K, x(U) 1–1 | 3 | 2 | | [DIAMOND_A4](#phase-sn-u-a4-diamond); _phase:sn-u:a4-diamond_ | C (diamond) · A4 · cF8 · Fd-3m (227) | tier A: standard phase name | not stable in 2 calculated diagram(s) | 0 | 2 | | [BCT_A5](#phase-sn-u-a5-bct); _phase:sn-u:a5-bct_ | beta-Sn · A5 · tI4 · I4_1/amd (141) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 300–505.08 K, x(U) 0–0 | 4 | 2 | | [BCC_A2](#phase-sn-u-bcc-a2); _phase:sn-u:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 1047.33–3999.84 K, x(U) 0.98014–1 | 8 | 2 | | [FCC_A1](#phase-sn-u-fcc-a1); _phase:sn-u:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | not stable in 2 calculated diagram(s) | 0 | 2 | | [HCP_A3](#phase-sn-u-hcp-a3); _phase:sn-u:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | not stable in 2 calculated diagram(s) | 0 | 2 | | [LIQUID](#phase-sn-u-liquid); _phase:sn-u:liquid_ | liquid | liquid | stable in 2 of 2 calculated diagram(s): 505.08–4000 K, x(U) 0–1 | 30 | 2 | | [SN2U](#phase-sn-u-sn2u); _phase:sn-u:sn2u_ | Ga2Zr · oC12 · Cmmm (65) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1627.22 K, x(U) 0.33333–0.33333 | 6 | 1 | | [SN2U3](#phase-sn-u-sn2u3); _phase:sn-u:sn2u3_ | Ga4Ti5 · hP18 · P6_3/mcm (193) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1695.57 K, x(U) 0.6–0.6 | 6 | 1 | | [SN3U_L12](#phase-sn-u-sn3u-l12); _phase:sn-u:sn3u-l12_ | AuCu3 · L1_2 · cP4 · Pm-3m (221) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 300–1604.74 K, x(U) 0.25–0.25 | 10 | 2 | | [SN4U5](#phase-sn-u-sn4u5); _phase:sn-u:sn4u5_ | Ga4Ti5 · hP18 · P6_3/mcm (193) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1664.19 K, x(U) 0.55556–0.55556 | 15 | 1 | | [SN5U3](#phase-sn-u-sn5u3); _phase:sn-u:sn5u3_ | Ga2Zr · oC12 · Cmmm (65) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1619.62 K, x(U) 0.375–0.375 | 4 | 1 | | [SN7U3](#phase-sn-u-sn7u3); _phase:sn-u:sn7u3_ | Ce3Sn7 · oC20 · Cmmm (65) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1615.46 K, x(U) 0.3–0.3 | 6 | 1 | | [SNU](#phase-sn-u-snu); _phase:sn-u:snu_ | InTh · oP24 · Pbcm (57) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1661.44 K, x(U) 0.5–0.5 | 6 | 1 | | [TETRAGONAL_U](#phase-sn-u-u-tetragonal); _phase:sn-u:u-tetragonal_ | | needs_review | stable in 2 of 2 calculated diagram(s): 942.02–1403.83 K, x(U) 0.99999–1 | 6 | 2 | ## ORTHORHOMBIC_A20 (Sn–U) - Id: `phase:sn-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 2 of 2 calculated diagram(s): 300–942.02 K, x(U) 1–1 - Literature: 3 values (3 accepted) from 1 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:a20-orthorhombic) Names (5): _corpus: _corpus:phase:sn-u:a20-orthorhombic, corpus:phase:sn-u:orthorhombic-a20 _paper: _paper:10.1007/s11669-021-00872-2:Orthorhombic_U _tdb: _tdb:SnU-21Wan.tdb:ORTHORHOMBIC_A20, tdb:SnU-87She.tdb:ORTHORHOMBIC_A20 ### TDB models of ORTHORHOMBIC_A20 (2): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): ORTHORHOMBIC_A20, type code %, sha256 `bfb5a924fae70c95…` ~~~~text 63: PHASE ORTHORHOMBIC_A20 % 1 1 ! 64: CONST ORTHORHOMBIC_A20 : SN U% : ! ~~~~ [SnU-87She.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-87She.tdb): ORTHORHOMBIC_A20, type code %, sha256 `52159592cd32f1c5…` ~~~~text 56: PHASE ORTHORHOMBIC_A20 % 1 1 ! 57: CONST ORTHORHOMBIC_A20 : U : ! ~~~~ Example references (4 of 4; assessments first): - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase; reports values for this phase_ - [doi:10.1007/BF02869271](https://doi.org/10.1007/BF02869271) R.I. Sheldon, E.M. Foltyn, D.E. Petersen, Bull. Alloy Phase Diag., 8, 347-52(1987). _assessment that models this phase_ - [doi:10.1016/0925-8388(94)01463-9](https://doi.org/10.1016/0925-8388%2894%2901463-9) A. Palenzona, P. Manfrinetti, The phase diagram of the USn system, Journal of Alloys and Compounds 221, 157-160 (1995). _cited as the source of values for this phase_ - [doi:10.1016/j.jct.2015.08.029](https://doi.org/10.1016/j.jct.2015.08.029) J. Wang, K. Wang, C.H. Ma, and L.D. Xie, J. Wang, K. Wang, C.H. Ma, and L.D. Xie, Critical Evaluation and Thermodynamic Optimization of the (U ? Bi), (U ? Si) and (U ? Sn) Binary Systems, J. Chem. Thermodyn., 2016, 92, p 158–167 _cited as the source of values for this phase_ ## DIAMOND_A4 (Sn–U) - Id: `phase:sn-u: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: Sn 1.0000 - Stability: not stable in 2 calculated diagram(s) - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:a4-diamond) Names (4): _corpus: _corpus:phase:sn-u:a4-diamond, corpus:phase:sn-u:diamond-a4 _tdb: _tdb:SnU-21Wan.tdb:DIAMOND_A4, tdb:SnU-87She.tdb:DIAMOND_A4 ### TDB models of DIAMOND_A4 (2): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): DIAMOND_A4, type code %, sha256 `bfb5a924fae70c95…` ~~~~text 53: PHASE DIAMOND_A4 % 1 1 ! 54: CONST DIAMOND_A4 : SN : ! ~~~~ [SnU-87She.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-87She.tdb): DIAMOND_A4, type code %, sha256 `52159592cd32f1c5…` ~~~~text 46: PHASE DIAMOND_A4 % 1 1 ! 47: CONST DIAMOND_A4 : SN : ! ~~~~ Example references (2 of 2; assessments first): - [doi:10.1007/BF02869271](https://doi.org/10.1007/BF02869271) R.I. Sheldon, E.M. Foltyn, D.E. Petersen, Bull. Alloy Phase Diag., 8, 347-52(1987). _assessment that models this phase_ - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase_ ## BCT_A5 (Sn–U) - Id: `phase:sn-u:a5-bct`; status `assigned` - Structure: beta-Sn · A5 · tI4 · I4_1/amd (141); type `st:a5-beta-sn-ti4`; tier A: standard phase name; confidence high - Stability: stable in 2 of 2 calculated diagram(s): 300–505.08 K, x(U) 0–0 - Literature: 4 values (4 accepted) from 2 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:a5-bct) Names (6): _corpus: _corpus:phase:sn-u:a5-bct, corpus:phase:sn-u:bct-a5 _paper: _paper:10.1007/bf02869271:βSn, paper:10.1007/s11669-021-00872-2:bct_Sn _tdb: _tdb:SnU-21Wan.tdb:BCT_A5, tdb:SnU-87She.tdb:BCT_A5 ### TDB models of BCT_A5 (2): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): BCT_A5, type code %, sha256 `bfb5a924fae70c95…` ~~~~text 58: PHASE BCT_A5 % 1 1 ! 59: CONST BCT_A5 : SN% U : ! ~~~~ [SnU-87She.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-87She.tdb): BCT_A5, type code %, sha256 `52159592cd32f1c5…` ~~~~text 51: PHASE BCT_A5 % 1 1 ! 52: CONST BCT_A5 : SN : ! ~~~~ Example references (4 of 4; assessments first): - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase; reports values for this phase_ - [doi:10.1007/BF02869271](https://doi.org/10.1007/BF02869271) R.I. Sheldon, E.M. Foltyn, D.E. Petersen, Bull. Alloy Phase Diag., 8, 347-52(1987). _assessment that models this phase; reports values for this phase_ - [doi:10.1016/0925-8388(94)01463-9](https://doi.org/10.1016/0925-8388%2894%2901463-9) A. Palenzona, P. Manfrinetti, The phase diagram of the USn system, Journal of Alloys and Compounds 221, 157-160 (1995). _cited as the source of values for this phase_ - [doi:10.1016/j.jct.2015.08.029](https://doi.org/10.1016/j.jct.2015.08.029) J. Wang, K. Wang, C.H. Ma, and L.D. Xie, J. Wang, K. Wang, C.H. Ma, and L.D. Xie, Critical Evaluation and Thermodynamic Optimization of the (U ? Bi), (U ? Si) and (U ? Sn) Binary Systems, J. Chem. Thermodyn., 2016, 92, p 158–167 _cited as the source of values for this phase_ ## BCC_A2 (Sn–U) - Id: `phase:sn-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 2 of 2 calculated diagram(s): 1047.33–3999.84 K, x(U) 0.98014–1 - Literature: 8 values (8 accepted) from 2 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:bcc-a2) Names (6): _corpus: _corpus:phase:sn-u:bcc-a2 _paper: _paper:10.1007/bf02869271:γU, paper:10.1007/s11669-021-00872-2:bcc_A2, paper:10.1007/s11669-021-00872-2:bcc_U _tdb: _tdb:SnU-21Wan.tdb:BCC_A2, tdb:SnU-87She.tdb:BCC_A2 ### TDB models of BCC_A2 (2): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): BCC_A2, type code %B, sha256 `bfb5a924fae70c95…` ~~~~text 43: PHASE BCC_A2 %B 2 1 3 ! 44: CONST BCC_A2 : SN U% : VA : ! ~~~~ [SnU-87She.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-87She.tdb): BCC_A2, type code %B, sha256 `52159592cd32f1c5…` ~~~~text 36: PHASE BCC_A2 %B 2 1 3 ! 37: CONST BCC_A2 : SN U% : VA : ! ~~~~ Example references (4 of 4; assessments first): - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase; reports values for this phase_ - [doi:10.1007/BF02869271](https://doi.org/10.1007/BF02869271) R.I. Sheldon, E.M. Foltyn, D.E. Petersen, Bull. Alloy Phase Diag., 8, 347-52(1987). _assessment that models this phase; reports values for this phase_ - [doi:10.1016/0925-8388(94)01463-9](https://doi.org/10.1016/0925-8388%2894%2901463-9) A. Palenzona, P. Manfrinetti, The phase diagram of the USn system, Journal of Alloys and Compounds 221, 157-160 (1995). _cited as the source of values for this phase_ - [doi:10.1016/j.jct.2015.08.029](https://doi.org/10.1016/j.jct.2015.08.029) J. Wang, K. Wang, C.H. Ma, and L.D. Xie, J. Wang, K. Wang, C.H. Ma, and L.D. Xie, Critical Evaluation and Thermodynamic Optimization of the (U ? Bi), (U ? Si) and (U ? Sn) Binary Systems, J. Chem. Thermodyn., 2016, 92, p 158–167 _cited as the source of values for this phase_ ## FCC_A1 (Sn–U) - Id: `phase:sn-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 2 calculated diagram(s) - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:fcc-a1) Names (3): _corpus: _corpus:phase:sn-u:fcc-a1 _tdb: _tdb:SnU-21Wan.tdb:FCC_A1, tdb:SnU-87She.tdb:FCC_A1 ### TDB models of FCC_A1 (2): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): FCC_A1, type code %A, sha256 `bfb5a924fae70c95…` ~~~~text 38: PHASE FCC_A1 %A 2 1 1 ! 39: CONST FCC_A1 : SN U : VA : ! ~~~~ [SnU-87She.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-87She.tdb): FCC_A1, type code %A, sha256 `52159592cd32f1c5…` ~~~~text 31: PHASE FCC_A1 %A 2 1 1 ! 32: CONST FCC_A1 : SN U : VA : ! ~~~~ Example references (2 of 2; assessments first): - [doi:10.1007/BF02869271](https://doi.org/10.1007/BF02869271) R.I. Sheldon, E.M. Foltyn, D.E. Petersen, Bull. Alloy Phase Diag., 8, 347-52(1987). _assessment that models this phase_ - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase_ ## HCP_A3 (Sn–U) - Id: `phase:sn-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 2 calculated diagram(s) - Literature: 0 values (0 accepted) from 0 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:hcp-a3) Names (3): _corpus: _corpus:phase:sn-u:hcp-a3 _tdb: _tdb:SnU-21Wan.tdb:HCP_A3, tdb:SnU-87She.tdb:HCP_A3 ### TDB models of HCP_A3 (2): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): HCP_A3, type code %A, sha256 `bfb5a924fae70c95…` ~~~~text 48: PHASE HCP_A3 %A 2 1 0.5 ! 49: CONST HCP_A3 : SN U : VA: ! ~~~~ [SnU-87She.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-87She.tdb): HCP_A3, type code %A, sha256 `52159592cd32f1c5…` ~~~~text 41: PHASE HCP_A3 %A 2 1 0.5 ! 42: CONST HCP_A3 : SN U : VA: ! ~~~~ Example references (2 of 2; assessments first): - [doi:10.1007/BF02869271](https://doi.org/10.1007/BF02869271) R.I. Sheldon, E.M. Foltyn, D.E. Petersen, Bull. Alloy Phase Diag., 8, 347-52(1987). _assessment that models this phase_ - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase_ ## LIQUID (Sn–U) - Id: `phase:sn-u:liquid`; status `assigned` - Structure: liquid; type `st:liquid`; liquid; confidence high - Stability: stable in 2 of 2 calculated diagram(s): 505.08–4000 K, x(U) 0–1 - Literature: 30 values (30 accepted) from 2 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:liquid) Names (5): _corpus: _corpus:phase:sn-u:liquid _paper: _paper:10.1007/bf02869271:L, paper:10.1007/s11669-021-00872-2:Liquid _tdb: _tdb:SnU-21Wan.tdb:LIQUID, tdb:SnU-87She.tdb:LIQUID ### TDB models of LIQUID (2): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): LIQUID, type code %, sha256 `bfb5a924fae70c95…` ~~~~text 33: PHASE LIQUID:L % 1 1 ! 34: CONST LIQUID:L : SN U : ! ~~~~ [SnU-87She.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-87She.tdb): LIQUID, type code %, sha256 `52159592cd32f1c5…` ~~~~text 26: PHASE LIQUID:L % 1 1 ! 27: CONST LIQUID:L : SN U : ! ~~~~ Example references (4 of 4; assessments first): - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase; reports values for this phase_ - [doi:10.1007/BF02869271](https://doi.org/10.1007/BF02869271) R.I. Sheldon, E.M. Foltyn, D.E. Petersen, Bull. Alloy Phase Diag., 8, 347-52(1987). _assessment that models this phase; reports values for this phase_ - [doi:10.1016/0925-8388(94)01463-9](https://doi.org/10.1016/0925-8388%2894%2901463-9) A. Palenzona, P. Manfrinetti, The phase diagram of the USn system, Journal of Alloys and Compounds 221, 157-160 (1995). _cited as the source of values for this phase_ - [doi:10.1016/j.jct.2015.08.029](https://doi.org/10.1016/j.jct.2015.08.029) J. Wang, K. Wang, C.H. Ma, and L.D. Xie, J. Wang, K. Wang, C.H. Ma, and L.D. Xie, Critical Evaluation and Thermodynamic Optimization of the (U ? Bi), (U ? Si) and (U ? Sn) Binary Systems, J. Chem. Thermodyn., 2016, 92, p 158–167 _cited as the source of values for this phase_ ## SN2U (Sn–U) - Id: `phase:sn-u:sn2u`; status `assigned` - Structure: Ga2Zr · oC12 · Cmmm (65); type `st:ga2zr-oc12`; 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](https://doi.org/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: Sn 0.6667, U 0.3333 - Stability: stable in 1 of 1 calculated diagram(s): 300–1627.22 K, x(U) 0.33333–0.33333 - Literature: 6 values (6 accepted) from 1 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:sn2u) Names (3): _corpus: _corpus:phase:sn-u:sn2u _paper: _paper:10.1007/s11669-021-00872-2:USn2 _tdb: _tdb:SnU-21Wan.tdb:SN2U ### TDB models of SN2U (1): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): SN2U, type code %, sha256 `bfb5a924fae70c95…` ~~~~text 83: PHASE SN2U % 2 2 1 ! 84: CONST SN2U : SN : U : ! ~~~~ Example references (3 of 3; assessments first): - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase; reports values for this phase_ - [doi:10.1016/0925-8388(94)01463-9](https://doi.org/10.1016/0925-8388%2894%2901463-9) A. Palenzona, P. Manfrinetti, The phase diagram of the USn system, Journal of Alloys and Compounds 221, 157-160 (1995). _cited as the source of values for this phase_ - [doi:10.1016/j.jct.2015.08.029](https://doi.org/10.1016/j.jct.2015.08.029) J. Wang, K. Wang, C.H. Ma, and L.D. Xie, J. Wang, K. Wang, C.H. Ma, and L.D. Xie, Critical Evaluation and Thermodynamic Optimization of the (U ? Bi), (U ? Si) and (U ? Sn) Binary Systems, J. Chem. Thermodyn., 2016, 92, p 158–167 _cited as the source of values for this phase_ ## SN2U3 (Sn–U) - Id: `phase:sn-u:sn2u3`; status `assigned` - Structure: Ga4Ti5 · hP18 · P6_3/mcm (193); type `st:ga4ti5-hp18`; 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](https://doi.org/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: Sn 0.4000, U 0.6000 - Stability: stable in 1 of 1 calculated diagram(s): 300–1695.57 K, x(U) 0.6–0.6 - Literature: 6 values (6 accepted) from 1 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:sn2u3) Names (3): _corpus: _corpus:phase:sn-u:sn2u3 _paper: _paper:10.1007/bf02869271:Sn2U3 _tdb: _tdb:SnU-87She.tdb:SN2U3 ### TDB models of SN2U3 (1): PHASE and CONSTITUENT statements as written [SnU-87She.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-87She.tdb): SN2U3, type code %, sha256 `52159592cd32f1c5…` ~~~~text 76: PHASE SN2U3 % 2 2 3 ! 77: CONST SN2U3 : SN : U : ! ~~~~ Example references (1 of 1; assessments first): - [doi:10.1007/BF02869271](https://doi.org/10.1007/BF02869271) R.I. Sheldon, E.M. Foltyn, D.E. Petersen, Bull. Alloy Phase Diag., 8, 347-52(1987). _assessment that models this phase; reports values for this phase_ ## SN3U_L12 (Sn–U) - Id: `phase:sn-u:sn3u-l12`; status `assigned` - Structure: AuCu3 · L1_2 · cP4 · Pm-3m (221); type `st:l1-2-aucu3-cp4`; tier A: standard phase name; confidence high - Caveat: DFT agrees: on-hull mp-aaaabece and oqmd-18132, space group 221 - Stoichiometry: Sn 0.7500, U 0.2500 - Stability: stable in 2 of 2 calculated diagram(s): 300–1604.74 K, x(U) 0.25–0.25 - Literature: 10 values (10 accepted) from 2 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:sn3u-l12) Names (7): _corpus: _corpus:phase:sn-u:sn3u-l12 _mp: _mp:mp-aaaabece _oqmd: _oqmd:oqmd-18132 _paper: _paper:10.1007/bf02869271:Sn3U, paper:10.1007/s11669-021-00872-2:USn3 _tdb: _tdb:SnU-21Wan.tdb:SN3U_L12, tdb:SnU-87She.tdb:SN3U_L12 ### TDB models of SN3U_L12 (2): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): SN3U_L12, type code %, sha256 `bfb5a924fae70c95…` ~~~~text 73: PHASE SN3U_L12 % 2 3 1 ! 74: CONST SN3U_L12 : SN : U : ! ~~~~ [SnU-87She.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-87She.tdb): SN3U_L12, type code %, sha256 `52159592cd32f1c5…` ~~~~text 66: PHASE SN3U_L12 % 2 3 1 ! 67: CONST SN3U_L12 : SN : U : ! ~~~~ Example references (4 of 4; assessments first): - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase; reports values for this phase_ - [doi:10.1007/BF02869271](https://doi.org/10.1007/BF02869271) R.I. Sheldon, E.M. Foltyn, D.E. Petersen, Bull. Alloy Phase Diag., 8, 347-52(1987). _assessment that models this phase; reports values for this phase_ - [doi:10.1016/0925-8388(94)01463-9](https://doi.org/10.1016/0925-8388%2894%2901463-9) A. Palenzona, P. Manfrinetti, The phase diagram of the USn system, Journal of Alloys and Compounds 221, 157-160 (1995). _cited as the source of values for this phase_ - [doi:10.1016/j.jct.2015.08.029](https://doi.org/10.1016/j.jct.2015.08.029) J. Wang, K. Wang, C.H. Ma, and L.D. Xie, J. Wang, K. Wang, C.H. Ma, and L.D. Xie, Critical Evaluation and Thermodynamic Optimization of the (U ? Bi), (U ? Si) and (U ? Sn) Binary Systems, J. Chem. Thermodyn., 2016, 92, p 158–167 _cited as the source of values for this phase_ ## SN4U5 (Sn–U) - Id: `phase:sn-u:sn4u5`; status `assigned` - Structure: Ga4Ti5 · hP18 · P6_3/mcm (193); type `st:ga4ti5-hp18`; 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](https://doi.org/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: Sn 0.4444, U 0.5556 - Stability: stable in 1 of 1 calculated diagram(s): 300–1664.19 K, x(U) 0.55556–0.55556 - Literature: 15 values (15 accepted) from 1 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:sn4u5) Names (3): _corpus: _corpus:phase:sn-u:sn4u5 _paper: _paper:10.1007/s11669-021-00872-2:U5Sn4 _tdb: _tdb:SnU-21Wan.tdb:SN4U5 ### TDB models of SN4U5 (1): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): SN4U5, type code %, sha256 `bfb5a924fae70c95…` ~~~~text 93: PHASE SN4U5 % 2 4 5 ! 94: CONST SN4U5 : SN : U : ! ~~~~ Example references (3 of 3; assessments first): - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase; reports values for this phase_ - [doi:10.1016/0925-8388(94)01463-9](https://doi.org/10.1016/0925-8388%2894%2901463-9) A. Palenzona, P. Manfrinetti, The phase diagram of the USn system, Journal of Alloys and Compounds 221, 157-160 (1995). _cited as the source of values for this phase_ - [doi:10.1016/j.jct.2015.08.029](https://doi.org/10.1016/j.jct.2015.08.029) J. Wang, K. Wang, C.H. Ma, and L.D. Xie, J. Wang, K. Wang, C.H. Ma, and L.D. Xie, Critical Evaluation and Thermodynamic Optimization of the (U ? Bi), (U ? Si) and (U ? Sn) Binary Systems, J. Chem. Thermodyn., 2016, 92, p 158–167 _cited as the source of values for this phase_ ## SN5U3 (Sn–U) - Id: `phase:sn-u:sn5u3`; status `assigned` - Structure: Ga2Zr · oC12 · Cmmm (65); type `st:ga2zr-oc12`; 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](https://doi.org/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: Sn 0.6250, U 0.3750 - Stability: stable in 1 of 1 calculated diagram(s): 300–1619.62 K, x(U) 0.375–0.375 - Literature: 4 values (4 accepted) from 1 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:sn5u3) Names (3): _corpus: _corpus:phase:sn-u:sn5u3 _paper: _paper:10.1007/bf02869271:Sn5U3 _tdb: _tdb:SnU-87She.tdb:SN5U3 ### TDB models of SN5U3 (1): PHASE and CONSTITUENT statements as written [SnU-87She.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-87She.tdb): SN5U3, type code %, sha256 `52159592cd32f1c5…` ~~~~text 71: PHASE SN5U3 % 2 5 3 ! 72: CONST SN5U3 : SN : U : ! ~~~~ Example references (1 of 1; assessments first): - [doi:10.1007/BF02869271](https://doi.org/10.1007/BF02869271) R.I. Sheldon, E.M. Foltyn, D.E. Petersen, Bull. Alloy Phase Diag., 8, 347-52(1987). _assessment that models this phase; reports values for this phase_ ## SN7U3 (Sn–U) - Id: `phase:sn-u:sn7u3`; status `assigned` - Structure: Ce3Sn7 · oC20 · Cmmm (65); type `st:ce3sn7-oc20`; 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](https://doi.org/10.1016/j.calphad.2025.102833) - Caveat: not certain from the name or DFT alone (no_on_hull_entry_in_oqmd, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system - Stoichiometry: Sn 0.7000, U 0.3000 - Stability: stable in 1 of 1 calculated diagram(s): 300–1615.46 K, x(U) 0.3–0.3 - Literature: 6 values (6 accepted) from 1 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:sn7u3) Names (3): _corpus: _corpus:phase:sn-u:sn7u3 _paper: _paper:10.1007/s11669-021-00872-2:U3Sn7 _tdb: _tdb:SnU-21Wan.tdb:SN7U3 ### TDB models of SN7U3 (1): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): SN7U3, type code %, sha256 `bfb5a924fae70c95…` ~~~~text 78: PHASE SN7U3 % 2 7 3 ! 79: CONST SN7U3 : SN : U : ! ~~~~ Example references (3 of 3; assessments first): - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase; reports values for this phase_ - [doi:10.1016/0925-8388(94)01463-9](https://doi.org/10.1016/0925-8388%2894%2901463-9) A. Palenzona, P. Manfrinetti, The phase diagram of the USn system, Journal of Alloys and Compounds 221, 157-160 (1995). _cited as the source of values for this phase_ - [doi:10.1016/j.jct.2015.08.029](https://doi.org/10.1016/j.jct.2015.08.029) J. Wang, K. Wang, C.H. Ma, and L.D. Xie, J. Wang, K. Wang, C.H. Ma, and L.D. Xie, Critical Evaluation and Thermodynamic Optimization of the (U ? Bi), (U ? Si) and (U ? Sn) Binary Systems, J. Chem. Thermodyn., 2016, 92, p 158–167 _cited as the source of values for this phase_ ## SNU (Sn–U) - Id: `phase:sn-u:snu`; status `assigned` - Structure: InTh · oP24 · Pbcm (57); type `st:inth-op24`; 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](https://doi.org/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: Sn 0.5000, U 0.5000 - Stability: stable in 1 of 1 calculated diagram(s): 300–1661.44 K, x(U) 0.5–0.5 - Literature: 6 values (6 accepted) from 1 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:snu) Names (3): _corpus: _corpus:phase:sn-u:snu _paper: _paper:10.1007/s11669-021-00872-2:USn _tdb: _tdb:SnU-21Wan.tdb:SNU ### TDB models of SNU (1): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): SNU, type code %, sha256 `bfb5a924fae70c95…` ~~~~text 88: PHASE SNU % 2 1 1 ! 89: CONST SNU : SN : U : ! ~~~~ Example references (3 of 3; assessments first): - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase; reports values for this phase_ - [doi:10.1016/0925-8388(94)01463-9](https://doi.org/10.1016/0925-8388%2894%2901463-9) A. Palenzona, P. Manfrinetti, The phase diagram of the USn system, Journal of Alloys and Compounds 221, 157-160 (1995). _cited as the source of values for this phase_ - [doi:10.1016/j.jct.2015.08.029](https://doi.org/10.1016/j.jct.2015.08.029) J. Wang, K. Wang, C.H. Ma, and L.D. Xie, J. Wang, K. Wang, C.H. Ma, and L.D. Xie, Critical Evaluation and Thermodynamic Optimization of the (U ? Bi), (U ? Si) and (U ? Sn) Binary Systems, J. Chem. Thermodyn., 2016, 92, p 158–167 _cited as the source of values for this phase_ ## TETRAGONAL_U (Sn–U) - Id: `phase:sn-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 — SnU-21Wan.tdb: 'Prototype beta-U (tP30, P4_2/mnm, SB: A_b)' - Candidate (tdb_comment): beta-U · tP30 · P4_2/mnm, SB: A_b — SnU-87She.tdb: 'Prototype beta-U (tP30, P4_2/mnm, SB: A_b)' - Stability: stable in 2 of 2 calculated diagram(s): 942.02–1403.83 K, x(U) 0.99999–1 - Literature: 6 values (6 accepted) from 1 papers - Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:sn-u:u-tetragonal) Names (5): _corpus: _corpus:phase:sn-u:u-tetragonal, corpus:phase:sn-u:tetragonal-u _paper: _paper:10.1007/s11669-021-00872-2:Tetragonal_U _tdb: _tdb:SnU-21Wan.tdb:TETRAGONAL_U, tdb:SnU-87She.tdb:TETRAGONAL_U ### TDB models of TETRAGONAL_U (2): PHASE and CONSTITUENT statements as written [SnU-21Wan.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-21Wan.tdb): TETRAGONAL_U, type code %, sha256 `bfb5a924fae70c95…` ~~~~text 68: PHASE TETRAGONAL_U % 1 1 ! 69: CONST TETRAGONAL_U : SN U% : ! ~~~~ [SnU-87She.tdb](https://orchid-project.org/data/databases/sgte-binary/SnU-87She.tdb): TETRAGONAL_U, type code %, sha256 `52159592cd32f1c5…` ~~~~text 61: PHASE TETRAGONAL_U % 1 1 ! 62: CONST TETRAGONAL_U : U : ! ~~~~ Example references (4 of 4; assessments first): - [doi:10.1007/s11669-021-00872-2](https://doi.org/10.1007/s11669-021-00872-2) Jun Wang, Yuan Yuan, Xiongying Cheng, Qin Zhang, Rongjian Pan, Aitao Tang, Thermodynamic Assessment of the U-Sn System and Extension to the U-Zr-Sn System, J. Phase Equilib. Diffus. 42, 194-205 (2021). _assessment that models this phase; reports values for this phase_ - [doi:10.1007/BF02869271](https://doi.org/10.1007/BF02869271) R.I. Sheldon, E.M. Foltyn, D.E. Petersen, Bull. Alloy Phase Diag., 8, 347-52(1987). _assessment that models this phase_ - [doi:10.1016/0925-8388(94)01463-9](https://doi.org/10.1016/0925-8388%2894%2901463-9) A. Palenzona, P. Manfrinetti, The phase diagram of the USn system, Journal of Alloys and Compounds 221, 157-160 (1995). _cited as the source of values for this phase_ - [doi:10.1016/j.jct.2015.08.029](https://doi.org/10.1016/j.jct.2015.08.029) J. Wang, K. Wang, C.H. Ma, and L.D. Xie, J. Wang, K. Wang, C.H. Ma, and L.D. Xie, Critical Evaluation and Thermodynamic Optimization of the (U ? Bi), (U ? Si) and (U ? Sn) Binary Systems, J. Chem. Thermodyn., 2016, 92, p 158–167 _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). https://doi.org/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). https://doi.org/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. ```bibtex @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} } ``` --- Derived data CC BY 4.0 ([licence](https://creativecommons.org/licenses/by/4.0/)): cite the ORCHID phase registry and the sources named on the page (TDB assessments, Hallstedt 2025, Materials Project, OQMD). TDB statements are quoted as written; parameter expressions are not reproduced. Field reference: [SCHEMA.md](https://data.orchid-project.org/phases/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt).