# Pd–Se phases

> Pd–Se system: 14 phases (tier A 4, tier B 1, tier C 5, liquid 1, needs_review 3); 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/PD-SE.html · Markdown: https://data.orchid-project.org/phases/pages/PD-SE.md

14 phases (tier A 4, tier B 1, tier C 5, liquid 1, needs_review 3); 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=PD-SE) · [full JSON](https://data.orchid-project.org/phases/systems/PD-SE.json) · [Pd–Se system page](https://data.orchid-project.org/systems/PD-SE.html) · [Markdown](https://data.orchid-project.org/phases/pages/PD-SE.md) · [field reference](https://data.orchid-project.org/phases/SCHEMA.md)

Table: Phases of the Pd–Se system (14)

| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---:|---:|
| [HEXAGONAL_A8](#phase-pd-se-a8-hexagonal); _phase:pd-se:a8-hexagonal_ | gamma-Se · A8 · hP3 · P3_121 (152) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–494 K, x(Se) 1–1 | 0 | 1 |
| [BCC_A2](#phase-pd-se-bcc-a2); _phase:pd-se:bcc-a2_ | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | not stable in 1 calculated diagram(s) | 0 | 1 |
| [FCC_A1](#phase-pd-se-fcc-a1); _phase:pd-se:fcc-a1_ | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | stable in 1 of 1 calculated diagram(s): 300–1867.63 K, x(Se) 0–0.0158 | 8 | 1 |
| [HCP_A3](#phase-pd-se-hcp-a3); _phase:pd-se:hcp-a3_ | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | not stable in 1 calculated diagram(s) | 0 | 1 |
| [LIQUID](#phase-pd-se-liquid); _phase:pd-se:liquid_ | liquid | liquid | stable in 1 of 1 calculated diagram(s): 494–2500 K, x(Se) 0–1 | 28 | 1 |
| [PD17SE15](#phase-pd-se-pd17se15); _phase:pd-se:pd17se15_ | Pd17Se15 · cP64 · Pm-3m (221) | tier B: DFT-supported (unique MP + OQMD match) | stable in 1 of 1 calculated diagram(s): 300–954.58 K, x(Se) 0.46875–0.46875 | 12 | 1 |
| [PD34SE11](#phase-pd-se-pd34se11); _phase:pd-se:pd34se11_ | Pd34Se11 · mP90 · P2_1/c (14) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–703.97 K, x(Se) 0.24444–0.24444 | 14 | 1 |
| [PD4SE_HT](#phase-pd-se-pd4se-ht); _phase:pd-se:pd4se-ht_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 800.35–818.06 K, x(Se) 0.2–0.2 | 12 | 1 |
| [PD4SE_LT](#phase-pd-se-pd4se-lt); _phase:pd-se:pd4se-lt_ | Pd4Se · tP10 · P-42_1c (114) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–800.35 K, x(Se) 0.2–0.2 | 8 | 1 |
| [PD7SE2](#phase-pd-se-pd7se2); _phase:pd-se:pd7se2_ | Pd7Se2 · mP18 · P2_1/c (14) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–811.27 K, x(Se) 0.22222–0.22222 | 11 | 1 |
| [PD7SE4](#phase-pd-se-pd7se4); _phase:pd-se:pd7se4_ | Pd7Se4 · oP22 · P2_12_12 (18) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–687.31 K, x(Se) 0.36364–0.36364 | 11 | 1 |
| [PD9SE2](#phase-pd-se-pd9se2); _phase:pd-se:pd9se2_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 673.64–910.06 K, x(Se) 0.18182–0.18182 | 12 | 1 |
| [PDSE](#phase-pd-se-pdse); _phase:pd-se:pdse_ |  | needs_review | stable in 1 of 1 calculated diagram(s): 468.56–890.81 K, x(Se) 0.5–0.5 | 7 | 1 |
| [PDSE2](#phase-pd-se-pdse2); _phase:pd-se:pdse2_ | PdSe2 · oP12 · Pbca (61) | tier C: assessor-stated (Hallstedt 2025 crystallographic table) | stable in 1 of 1 calculated diagram(s): 300–1457.5 K, x(Se) 0.66667–0.66667 | 11 | 1 |

## HEXAGONAL_A8 (Pd–Se)

- Id: `phase:pd-se:a8-hexagonal`; status `assigned`
- Structure: gamma-Se · A8 · hP3 · P3_121 (152); type `st:a8-gamma-se-hp3`; tier A: standard phase name; confidence high
- Stoichiometry: Se 1.0000
- Stability: stable in 1 of 1 calculated diagram(s): 300–494 K, x(Se) 1–1
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:a8-hexagonal)

Names (2): _corpus: _corpus:phase:pd-se:a8-hexagonal  
_tdb: _tdb:PdSe-14Bor.tdb:HEXAGONAL_A8  


### TDB models of HEXAGONAL_A8 (1): PHASE and CONSTITUENT statements as written

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): HEXAGONAL_A8, type code %, sha256 `e26c4eccbccb63c1…`

~~~~text
42: PHASE HEXAGONAL_A8 % 1 1 !
43: CONST HEXAGONAL_A8 : SE : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase_

## BCC_A2 (Pd–Se)

- Id: `phase:pd-se:bcc-a2`; status `assigned`
- Structure: W · A2 · cI2 · Im-3m (229); type `st:a2-w-ci2`; tier A: standard phase name; confidence high
- Stoichiometry: Pd 1.0000
- Stability: not stable in 1 calculated diagram(s)
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:bcc-a2)

Names (2): _corpus: _corpus:phase:pd-se:bcc-a2  
_tdb: _tdb:PdSe-14Bor.tdb:BCC_A2  


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

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): BCC_A2, type code %B, sha256 `e26c4eccbccb63c1…`

~~~~text
32: PHASE BCC_A2 %B 2 1 3 !
33: CONST BCC_A2 : PD : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase_

## FCC_A1 (Pd–Se)

- Id: `phase:pd-se:fcc-a1`; status `assigned`
- Structure: Cu · A1 · cF4 · Fm-3m (225); type `st:a1-cu-cf4`; tier A: standard phase name; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 300–1867.63 K, x(Se) 0–0.0158
- Literature: 8 values (8 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:fcc-a1)

Names (3): _corpus: _corpus:phase:pd-se:fcc-a1  
_paper: _paper:10.1016/j.jnucmat.2014.03.044:FCC  
_tdb: _tdb:PdSe-14Bor.tdb:FCC_A1  


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

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): FCC_A1, type code %A, sha256 `e26c4eccbccb63c1…`

~~~~text
27: PHASE FCC_A1 %A 2 1 1 !
28: CONST FCC_A1 : PD% SE : VA : !
~~~~

Example references (3 of 3; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(87)90444-9](https://doi.org/10.1016/0022-5088%2887%2990444-9) T. Takabatake, M. Ishikawa, J.L. Jorda, Superconductivity and phase relations in the Pd-Se system, Journal of the Less Common Metals 134, 79-89 (1987).  
_cited as the source of values for this phase_
- [doi:10.3891/acta.chem.scand.33a-0251](https://doi.org/10.3891/acta.chem.scand.33a-0251) Torbjørn Olsen, Erling Røst, Fredrik Grønvold, Arne F. Andresen, Eberhard Hoyer, V. P. Spiridonov et al., Phase Relationships of Palladium Selenides., Acta Chem. Scand. 33a, 251-256 (1979).  
_cited as the source of values for this phase_

## HCP_A3 (Pd–Se)

- Id: `phase:pd-se: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: Pd 1.0000
- Stability: not stable in 1 calculated diagram(s)
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:hcp-a3)

Names (2): _corpus: _corpus:phase:pd-se:hcp-a3  
_tdb: _tdb:PdSe-14Bor.tdb:HCP_A3  


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

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): HCP_A3, type code %A, sha256 `e26c4eccbccb63c1…`

~~~~text
37: PHASE HCP_A3 %A 2 1 0.5 !
38: CONST HCP_A3 : PD : VA : !
~~~~

Example references (1 of 1; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase_

## LIQUID (Pd–Se)

- Id: `phase:pd-se:liquid`; status `assigned`
- Structure: liquid; type `st:liquid`; liquid; confidence high
- Stability: stable in 1 of 1 calculated diagram(s): 494–2500 K, x(Se) 0–1
- Literature: 28 values (28 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:liquid)

Names (3): _corpus: _corpus:phase:pd-se:liquid  
_paper: _paper:10.1016/j.jnucmat.2014.03.044:L  
_tdb: _tdb:PdSe-14Bor.tdb:LIQUID  


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

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): LIQUID, type code %, sha256 `e26c4eccbccb63c1…`

~~~~text
22: PHASE LIQUID:L % 1 1 !
23: CONST LIQUID:L : PD SE : !
~~~~

Example references (3 of 3; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase; reports values for this phase_
- [doi:10.3891/acta.chem.scand.33a-0251](https://doi.org/10.3891/acta.chem.scand.33a-0251) Torbjørn Olsen, Erling Røst, Fredrik Grønvold, Arne F. Andresen, Eberhard Hoyer, V. P. Spiridonov et al., Phase Relationships of Palladium Selenides., Acta Chem. Scand. 33a, 251-256 (1979).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(87)90444-9](https://doi.org/10.1016/0022-5088%2887%2990444-9) T. Takabatake, M. Ishikawa, J.L. Jorda, Superconductivity and phase relations in the Pd-Se system, Journal of the Less Common Metals 134, 79-89 (1987).  
_cited as the source of values for this phase_

## PD17SE15 (Pd–Se)

- Id: `phase:pd-se:pd17se15`; status `assigned`
- Structure: Pd17Se15 · cP64 · Pm-3m (221); type `st:pd17se15-cp64`; tier B: DFT-supported (unique MP + OQMD match); confidence high
- Stoichiometry: Pd 0.5312, Se 0.4688
- Stability: stable in 1 of 1 calculated diagram(s): 300–954.58 K, x(Se) 0.46875–0.46875
- Literature: 12 values (12 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:pd17se15)

Names (5): _corpus: _corpus:phase:pd-se:pd17se15  
_mp: _mp:mp-aaaabgfd  
_oqmd: _oqmd:oqmd-92418  
_paper: _paper:10.1016/j.jnucmat.2014.03.044:Pd17Se15  
_tdb: _tdb:PdSe-14Bor.tdb:PD17SE15  


### TDB models of PD17SE15 (1): PHASE and CONSTITUENT statements as written

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): PD17SE15, type code %, sha256 `e26c4eccbccb63c1…`

~~~~text
77: PHASE PD17SE15 % 2 17 15 !
78: CONST PD17SE15 : PD : SE : !
~~~~

Example references (5 of 5; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase; reports values for this phase_
- [doi:10.3891/acta.chem.scand.33a-0251](https://doi.org/10.3891/acta.chem.scand.33a-0251) Torbjørn Olsen, Erling Røst, Fredrik Grønvold, Arne F. Andresen, Eberhard Hoyer, V. P. Spiridonov et al., Phase Relationships of Palladium Selenides., Acta Chem. Scand. 33a, 251-256 (1979).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(87)90444-9](https://doi.org/10.1016/0022-5088%2887%2990444-9) T. Takabatake, M. Ishikawa, J.L. Jorda, Superconductivity and phase relations in the Pd-Se system, Journal of the Less Common Metals 134, 79-89 (1987).  
_cited as the source of values for this phase_
- [doi:10.1107/s0365110x62001929](https://doi.org/10.1107/s0365110x62001929) S. Geller, The crystal structure of Pd17Se15, Acta Cryst 15, 713-721 (1962).  
_cited as the source of values for this phase_
- [doi:10.3891/acta.chem.scand.14-1623](https://doi.org/10.3891/acta.chem.scand.14-1623) Arne Kjekshus, Anna Nylund, S. Rundqvist, E. Varde, Gertrud Westin, High Temperature X-Ray Study of the Thermal Expansion of Pd9Se8 and Rh9S8., Acta Chem. Scand. 14, 1623-1626 (1960).  
_cited as the source of values for this phase_

## PD34SE11 (Pd–Se)

- Id: `phase:pd-se:pd34se11`; status `assigned`
- Structure: Pd34Se11 · mP90 · P2_1/c (14); type `st:pd34se11-mp90`; 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: Pd 0.7556, Se 0.2444
- Stability: stable in 1 of 1 calculated diagram(s): 300–703.97 K, x(Se) 0.24444–0.24444
- Literature: 14 values (14 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:pd34se11)

Names (3): _corpus: _corpus:phase:pd-se:pd34se11  
_paper: _paper:10.1016/j.jnucmat.2014.03.044:Pd34Se11  
_tdb: _tdb:PdSe-14Bor.tdb:PD34SE11  


### TDB models of PD34SE11 (1): PHASE and CONSTITUENT statements as written

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): PD34SE11, type code %, sha256 `e26c4eccbccb63c1…`

~~~~text
67: PHASE PD34SE11 % 2 34 11 !
68: CONST PD34SE11 : PD : SE : !
~~~~

Example references (3 of 3; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(87)90444-9](https://doi.org/10.1016/0022-5088%2887%2990444-9) T. Takabatake, M. Ishikawa, J.L. Jorda, Superconductivity and phase relations in the Pd-Se system, Journal of the Less Common Metals 134, 79-89 (1987).  
_cited as the source of values for this phase_
- [doi:10.3891/acta.chem.scand.33a-0251](https://doi.org/10.3891/acta.chem.scand.33a-0251) Torbjørn Olsen, Erling Røst, Fredrik Grønvold, Arne F. Andresen, Eberhard Hoyer, V. P. Spiridonov et al., Phase Relationships of Palladium Selenides., Acta Chem. Scand. 33a, 251-256 (1979).  
_cited as the source of values for this phase_

## PD4SE_HT (Pd–Se)

- Id: `phase:pd-se:pd4se-ht`; status `needs_review`
- No structure assigned. Why: no_structure_token; polymorph_family:other phases of this system have the same composition; sgte_mmc2_row_incomplete
- Candidate (dft_mp): P-42_1c (114) — on-hull MP Pd4Se at x(SE)=0.2000
- Candidate (dft_oqmd): P-421c (114) — on-hull OQMD Pd4 Se1 at x(SE)=0.2000
- Candidate (literature_printed): (Pd4Se-ht) · ? — printed with a label mapped to this phase
- Candidate (sgte_mmc2): (Pd4Se-ht) — Hallstedt 2025 mmc2 row for PD4SE_HT: Pd4Se (high T)
- Stoichiometry: Pd 0.8000, Se 0.2000
- Stability: stable in 1 of 1 calculated diagram(s): 800.35–818.06 K, x(Se) 0.2–0.2
- Literature: 12 values (12 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:pd4se-ht)

Names (3): _corpus: _corpus:phase:pd-se:pd4se-ht  
_paper: _paper:10.1016/j.jnucmat.2014.03.044:β-Pd4Se  
_tdb: _tdb:PdSe-14Bor.tdb:PD4SE_HT  


### TDB models of PD4SE_HT (1): PHASE and CONSTITUENT statements as written

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): PD4SE_HT, type code %, sha256 `e26c4eccbccb63c1…`

~~~~text
57: PHASE PD4SE_HT % 2 4 1 !
58: CONST PD4SE_HT : PD : SE : !
~~~~

Example references (3 of 3; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(87)90444-9](https://doi.org/10.1016/0022-5088%2887%2990444-9) T. Takabatake, M. Ishikawa, J.L. Jorda, Superconductivity and phase relations in the Pd-Se system, Journal of the Less Common Metals 134, 79-89 (1987).  
_cited as the source of values for this phase_
- [doi:10.3891/acta.chem.scand.33a-0251](https://doi.org/10.3891/acta.chem.scand.33a-0251) Torbjørn Olsen, Erling Røst, Fredrik Grønvold, Arne F. Andresen, Eberhard Hoyer, V. P. Spiridonov et al., Phase Relationships of Palladium Selenides., Acta Chem. Scand. 33a, 251-256 (1979).  
_cited as the source of values for this phase_

## PD4SE_LT (Pd–Se)

- Id: `phase:pd-se:pd4se-lt`; status `assigned`
- Structure: Pd4Se · tP10 · P-42_1c (114); type `st:pd4se-tp10`; 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_structure_token, polymorph_family:other phases of this system have the same composition); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: Pd 0.8000, Se 0.2000
- Stability: stable in 1 of 1 calculated diagram(s): 300–800.35 K, x(Se) 0.2–0.2
- Literature: 8 values (8 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:pd4se-lt)

Names (4): _corpus: _corpus:phase:pd-se:pd4se-lt  
_paper: _paper:10.1016/j.jnucmat.2014.03.044:α, paper:10.1016/j.jnucmat.2014.03.044:α-Pd4Se  
_tdb: _tdb:PdSe-14Bor.tdb:PD4SE_LT  


### TDB models of PD4SE_LT (1): PHASE and CONSTITUENT statements as written

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): PD4SE_LT, type code %, sha256 `e26c4eccbccb63c1…`

~~~~text
52: PHASE PD4SE_LT % 2 4 1 !
53: CONST PD4SE_LT : PD : SE : !
~~~~

Example references (3 of 3; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(87)90444-9](https://doi.org/10.1016/0022-5088%2887%2990444-9) T. Takabatake, M. Ishikawa, J.L. Jorda, Superconductivity and phase relations in the Pd-Se system, Journal of the Less Common Metals 134, 79-89 (1987).  
_cited as the source of values for this phase_
- [doi:10.3891/acta.chem.scand.33a-0251](https://doi.org/10.3891/acta.chem.scand.33a-0251) Torbjørn Olsen, Erling Røst, Fredrik Grønvold, Arne F. Andresen, Eberhard Hoyer, V. P. Spiridonov et al., Phase Relationships of Palladium Selenides., Acta Chem. Scand. 33a, 251-256 (1979).  
_cited as the source of values for this phase_

## PD7SE2 (Pd–Se)

- Id: `phase:pd-se:pd7se2`; status `assigned`
- Structure: Pd7Se2 · mP18 · P2_1/c (14); type `st:pd7se2-mp18`; 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: Pd 0.7778, Se 0.2222
- Stability: stable in 1 of 1 calculated diagram(s): 300–811.27 K, x(Se) 0.22222–0.22222
- Literature: 11 values (11 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:pd7se2)

Names (3): _corpus: _corpus:phase:pd-se:pd7se2  
_paper: _paper:10.1016/j.jnucmat.2014.03.044:Pd7Se2  
_tdb: _tdb:PdSe-14Bor.tdb:PD7SE2  


### TDB models of PD7SE2 (1): PHASE and CONSTITUENT statements as written

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): PD7SE2, type code %, sha256 `e26c4eccbccb63c1…`

~~~~text
62: PHASE PD7SE2 % 2 7 2 !
63: CONST PD7SE2 : PD : SE : !
~~~~

Example references (3 of 3; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase; reports values for this phase_
- [doi:10.3891/acta.chem.scand.33a-0251](https://doi.org/10.3891/acta.chem.scand.33a-0251) Torbjørn Olsen, Erling Røst, Fredrik Grønvold, Arne F. Andresen, Eberhard Hoyer, V. P. Spiridonov et al., Phase Relationships of Palladium Selenides., Acta Chem. Scand. 33a, 251-256 (1979).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(87)90444-9](https://doi.org/10.1016/0022-5088%2887%2990444-9) T. Takabatake, M. Ishikawa, J.L. Jorda, Superconductivity and phase relations in the Pd-Se system, Journal of the Less Common Metals 134, 79-89 (1987).  
_cited as the source of values for this phase_

## PD7SE4 (Pd–Se)

- Id: `phase:pd-se:pd7se4`; status `assigned`
- Structure: Pd7Se4 · oP22 · P2_12_12 (18); type `st:pd7se4-op22`; 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: Pd 0.6364, Se 0.3636
- Stability: stable in 1 of 1 calculated diagram(s): 300–687.31 K, x(Se) 0.36364–0.36364
- Literature: 11 values (11 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:pd7se4)

Names (3): _corpus: _corpus:phase:pd-se:pd7se4  
_paper: _paper:10.1016/j.jnucmat.2014.03.044:Pd7Se4  
_tdb: _tdb:PdSe-14Bor.tdb:PD7SE4  


### TDB models of PD7SE4 (1): PHASE and CONSTITUENT statements as written

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): PD7SE4, type code %, sha256 `e26c4eccbccb63c1…`

~~~~text
72: PHASE PD7SE4 % 2 7 4 !
73: CONST PD7SE4 : PD : SE : !
~~~~

Example references (4 of 4; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase; reports values for this phase_
- [doi:10.3891/acta.chem.scand.33a-0251](https://doi.org/10.3891/acta.chem.scand.33a-0251) Torbjørn Olsen, Erling Røst, Fredrik Grønvold, Arne F. Andresen, Eberhard Hoyer, V. P. Spiridonov et al., Phase Relationships of Palladium Selenides., Acta Chem. Scand. 33a, 251-256 (1979).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(78)90133-9](https://doi.org/10.1016/0022-5088%2878%2990133-9) T. Matković, K. Schubert, Kristallstruktur von Pd7Se4, Journal of the Less Common Metals 59, P57-P63 (1978).  
_cited as the source of values for this phase_
- [doi:10.1016/0022-5088(87)90444-9](https://doi.org/10.1016/0022-5088%2887%2990444-9) T. Takabatake, M. Ishikawa, J.L. Jorda, Superconductivity and phase relations in the Pd-Se system, Journal of the Less Common Metals 134, 79-89 (1987).  
_cited as the source of values for this phase_

## PD9SE2 (Pd–Se)

- Id: `phase:pd-se:pd9se2`; status `needs_review`
- No structure assigned. Why: no_on_hull_entry_in_both; no_structure_token; sgte_mmc2_row_incomplete
- Candidate (literature_printed): (Pd9Se2) · ? — printed with a label mapped to this phase
- Candidate (sgte_mmc2): (Pd9Se2) — Hallstedt 2025 mmc2 row for PD9SE2: Pd9Se2
- Stoichiometry: Pd 0.8182, Se 0.1818
- Stability: stable in 1 of 1 calculated diagram(s): 673.64–910.06 K, x(Se) 0.18182–0.18182
- Literature: 12 values (12 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:pd9se2)

Names (3): _corpus: _corpus:phase:pd-se:pd9se2  
_paper: _paper:10.1016/j.jnucmat.2014.03.044:Pd9Se2  
_tdb: _tdb:PdSe-14Bor.tdb:PD9SE2  


### TDB models of PD9SE2 (1): PHASE and CONSTITUENT statements as written

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): PD9SE2, type code %, sha256 `e26c4eccbccb63c1…`

~~~~text
47: PHASE PD9SE2 % 2 9 2 !
48: CONST PD9SE2 : PD : SE : !
~~~~

Example references (3 of 3; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1016/0022-5088(87)90444-9](https://doi.org/10.1016/0022-5088%2887%2990444-9) T. Takabatake, M. Ishikawa, J.L. Jorda, Superconductivity and phase relations in the Pd-Se system, Journal of the Less Common Metals 134, 79-89 (1987).  
_cited as the source of values for this phase_
- [doi:10.3891/acta.chem.scand.33a-0251](https://doi.org/10.3891/acta.chem.scand.33a-0251) Torbjørn Olsen, Erling Røst, Fredrik Grønvold, Arne F. Andresen, Eberhard Hoyer, V. P. Spiridonov et al., Phase Relationships of Palladium Selenides., Acta Chem. Scand. 33a, 251-256 (1979).  
_cited as the source of values for this phase_

## PDSE (Pd–Se)

- Id: `phase:pd-se:pdse`; status `needs_review`
- No structure assigned. Why: assessment_declared_blocked_by:sgte_mmc2_row_disagrees_with_dft; no_structure_token; sgte_mmc2_row_disagrees_with_dft
- Candidate (dft_mp): P4_2/m (84) — on-hull MP PdSe at x(SE)=0.5000
- Candidate (dft_oqmd): P42/m (84) — on-hull OQMD Pd1 Se1 at x(SE)=0.5000
- Candidate (literature_printed): Pd(S,Se) · tP48 — printed with a label mapped to this phase
- Candidate (sgte_mmc2): Pd(S,Se) · tP48 · P4_2/mbc (135) — Hallstedt 2025 mmc2 row for PDSE: PdSe
- Candidate (tdb_comment): Pd · S · Se — PdSe-14Bor.tdb: 'Prototype Pd(S,Se) (tP48, P4_2/mbc)'
- Stoichiometry: Pd 0.5000, Se 0.5000
- Stability: stable in 1 of 1 calculated diagram(s): 468.56–890.81 K, x(Se) 0.5–0.5
- Literature: 7 values (7 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:pdse)

Names (3): _corpus: _corpus:phase:pd-se:pdse  
_paper: _paper:10.1016/j.jnucmat.2014.03.044:PdSe  
_tdb: _tdb:PdSe-14Bor.tdb:PDSE  


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

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): PDSE, type code %, sha256 `e26c4eccbccb63c1…`

~~~~text
82: PHASE PDSE % 2 1 1 !
83: CONST PDSE : PD : SE : !
~~~~

Example references (2 of 2; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase; reports values for this phase_
- [doi:10.3891/acta.chem.scand.33a-0251](https://doi.org/10.3891/acta.chem.scand.33a-0251) Torbjørn Olsen, Erling Røst, Fredrik Grønvold, Arne F. Andresen, Eberhard Hoyer, V. P. Spiridonov et al., Phase Relationships of Palladium Selenides., Acta Chem. Scand. 33a, 251-256 (1979).  
_cited as the source of values for this phase_

## PDSE2 (Pd–Se)

- Id: `phase:pd-se:pdse2`; status `assigned`
- Structure: PdSe2 · oP12 · Pbca (61); type `st:pdse2-op12`; 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 (mp_oqmd_space_groups_differ, no_structure_token); structure as stated in the SGTE crystallographic table for this phase name and system
- Stoichiometry: Pd 0.3333, Se 0.6667
- Stability: stable in 1 of 1 calculated diagram(s): 300–1457.5 K, x(Se) 0.66667–0.66667
- Literature: 11 values (11 accepted) from 1 papers
- Interactive: [phase registry entry](https://orchid-project.org/phases/#phase:pd-se:pdse2)

Names (3): _corpus: _corpus:phase:pd-se:pdse2  
_paper: _paper:10.1016/j.jnucmat.2014.03.044:PdSe2  
_tdb: _tdb:PdSe-14Bor.tdb:PDSE2  


### TDB models of PDSE2 (1): PHASE and CONSTITUENT statements as written

[PdSe-14Bor.tdb](https://orchid-project.org/data/databases/sgte-binary/PdSe-14Bor.tdb): PDSE2, type code %, sha256 `e26c4eccbccb63c1…`

~~~~text
87: PHASE PDSE2 % 2 1 2 !
88: CONST PDSE2 : PD : SE : !
~~~~

Example references (5 of 5; assessments first): 

- [doi:10.1016/j.jnucmat.2014.03.044](https://doi.org/10.1016/j.jnucmat.2014.03.044) S. Bordier, A. Chocard, S. Gossé, Thermodynamic assessment of the palladium–selenium (Pd–Se) system, Journal of Nuclear Materials 451, 120-129 (2014).  
_assessment that models this phase; reports values for this phase_
- [doi:10.1107/s0365110x57000948](https://doi.org/10.1107/s0365110x57000948) F. Grønvold, E. Røst, The crystal structure of PdSe2 and PdS2, Acta Cryst 10, 329-331 (1957).  
_cited as the source of values for this phase_
- [doi:10.3891/acta.chem.scand.10-1620](https://doi.org/10.3891/acta.chem.scand.10-1620) Fredrik Grønvold, Erling Røst, Bengt Aurivillius, N. A. Eliasson, B. Thorell, On the Sulfides, Selenides, and Tellurides of Palladium., Acta Chem. Scand. 10, 1620-1634 (1956).  
_cited as the source of values for this phase_
- [doi:10.1134/s0016702911030098](https://doi.org/10.1134/s0016702911030098) T. A. Stolyarova, M. V. Voronin, E. G. Osadchii, Enthalpies of formation of verbeekite (PdSe2) and palladseite (Pd17Se15) from elements, Geochem. Int. 49, 309-313 (2011).  
_cited as the source of values for this phase_
- [doi:10.3891/acta.chem.scand.33a-0251](https://doi.org/10.3891/acta.chem.scand.33a-0251) Torbjørn Olsen, Erling Røst, Fredrik Grønvold, Arne F. Andresen, Eberhard Hoyer, V. P. Spiridonov et al., Phase Relationships of Palladium Selenides., Acta Chem. Scand. 33a, 251-256 (1979).  
_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).