C–Pr phases

8 phases (tier A 6, tier C 1, liquid 1); 7 stable in a calculated diagram. Structure types are assigned only when the stored evidence supports an assignment under the stated tier rules (tier A: standard phase name; tier B: unique Materials Project + OQMD on-hull match, DFT-supported; tier C: one structure stated by the assessment's crystallographic table, assessor-stated); other phases list candidates and are marked needs_review. Stability is from phase diagrams calculated with pycalphad from the SGTE binary collection (evidence class: model).

Data: interactive registry · full JSON · C–Pr system page · Markdown · field reference

Phases of the C–Pr system (8)
Phase	Structure	Basis	Stability (calculated)	TDB models
DIAMOND_A4 phase:c-pr:a4-diamond	C (diamond) · A4 · cF8 · Fd-3m (227)	tier A: standard phase name	not stable in 1 calculated diagram(s)	1
GRAPHITE_A9 phase:c-pr:a9-graphite	C (graphite) · A9 · hP4 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–4000 K, x(C) 1–1	1
BCC_A2 phase:c-pr:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 948.99–2429 K, x(C) 0–0.0773	1
DHCP phase:c-pr:dhcp-a3	alpha-La · A3' · hP4 · P6_3/mmc (194)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1153 K, x(C) 0–0.04431	1
LIQUID phase:c-pr:liquid	liquid	liquid	stable in 1 of 1 calculated diagram(s): 1072.12–4000 K, x(C) 0–0.86142	1
PR2C3_D5C phase:c-pr:pr2c3-d5c	Pu2C3 · D5_c · cI40 · I-43d (220)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1821.15 K, x(C) 0.54404–0.6	1
PRC2_BETA phase:c-pr:prc2-beta	CaC2 · cF36 · Fm-3m (225)	tier C: assessor-stated (Hallstedt 2025 crystallographic table)	stable in 1 of 1 calculated diagram(s): 1427.43–2589.18 K, x(C) 0.65795–0.66612	1
PRC2_C11A phase:c-pr:prc2-c11a	CaC2 · C11_a · tI6 · I4/mmm (139)	tier A: standard phase name	stable in 1 of 1 calculated diagram(s): 300–1413.6 K, x(C) 0.66667–0.66667	1

DIAMOND_A4 (C–Pr)

Id: phase:c-pr: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: C 1.0000
Stability: not stable in 1 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-pr:a4-diamond
tdb: tdb:PrC-11Pen.tdb:DIAMOND_A4

TDB models of DIAMOND_A4 (1): PHASE and CONSTITUENT statements as written

PrC-11Pen.tdb: DIAMOND_A4, type code %, sha256 7207a325d93d7b08…

46: PHASE DIAMOND_A4 % 1 1 !
47: CONST DIAMOND_A4 : C : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.09.002 Yingbiao Peng, Yong Du, Lijun Zhang, Chunsheng Sha, Shuhong Liu, Feng Zheng et al., Thermodynamic modeling of the C–RE (RE=La, Ce and Pr) systems, Calphad 35, 533-541 (2011).
assessment that models this phase

GRAPHITE_A9 (C–Pr)

Id: phase:c-pr:a9-graphite; status assigned
Structure: C (graphite) · A9 · hP4 · P6_3/mmc (194); type st:a9-c-graphite-hp4; tier A: standard phase name; confidence high
Stoichiometry: C 1.0000
Stability: stable in 1 of 1 calculated diagram(s): 300–4000 K, x(C) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-pr:a9-graphite
tdb: tdb:PrC-11Pen.tdb:GRAPHITE_A9

TDB models of GRAPHITE_A9 (1): PHASE and CONSTITUENT statements as written

PrC-11Pen.tdb: GRAPHITE_A9, type code %, sha256 7207a325d93d7b08…

51: PHASE GRAPHITE_A9 % 1 1 !
52: CONST GRAPHITE_A9 : C : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.09.002 Yingbiao Peng, Yong Du, Lijun Zhang, Chunsheng Sha, Shuhong Liu, Feng Zheng et al., Thermodynamic modeling of the C–RE (RE=La, Ce and Pr) systems, Calphad 35, 533-541 (2011).
assessment that models this phase

BCC_A2 (C–Pr)

Id: phase:c-pr:bcc-a2; status assigned
Structure: W · A2 · cI2 · Im-3m (229); type st:a2-w-ci2; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 948.99–2429 K, x(C) 0–0.0773
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-pr:bcc-a2
tdb: tdb:PrC-11Pen.tdb:BCC_A2

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

PrC-11Pen.tdb: BCC_A2, type code %B, sha256 7207a325d93d7b08…

36: PHASE BCC_A2 %B 2 1 3 !
37: CONST BCC_A2 : PR : C VA% : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.09.002 Yingbiao Peng, Yong Du, Lijun Zhang, Chunsheng Sha, Shuhong Liu, Feng Zheng et al., Thermodynamic modeling of the C–RE (RE=La, Ce and Pr) systems, Calphad 35, 533-541 (2011).
assessment that models this phase

DHCP (C–Pr)

Id: phase:c-pr:dhcp-a3; status assigned
Structure: alpha-La · A3' · hP4 · P6_3/mmc (194); type st:a3-alpha-la-hp4; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–1153 K, x(C) 0–0.04431
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-pr:dhcp-a3
tdb: tdb:PrC-11Pen.tdb:DHCP

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

PrC-11Pen.tdb: DHCP, type code %, sha256 7207a325d93d7b08…

41: PHASE DHCP % 2 1 1 !
42: CONST DHCP : PR : C VA% : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.09.002 Yingbiao Peng, Yong Du, Lijun Zhang, Chunsheng Sha, Shuhong Liu, Feng Zheng et al., Thermodynamic modeling of the C–RE (RE=La, Ce and Pr) systems, Calphad 35, 533-541 (2011).
assessment that models this phase

LIQUID (C–Pr)

Id: phase:c-pr:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 1072.12–4000 K, x(C) 0–0.86142
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-pr:liquid
tdb: tdb:PrC-11Pen.tdb:LIQUID

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

PrC-11Pen.tdb: LIQUID, type code %, sha256 7207a325d93d7b08…

31: PHASE LIQUID:L % 1 1 !
32: CONST LIQUID:L : C PR : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.09.002 Yingbiao Peng, Yong Du, Lijun Zhang, Chunsheng Sha, Shuhong Liu, Feng Zheng et al., Thermodynamic modeling of the C–RE (RE=La, Ce and Pr) systems, Calphad 35, 533-541 (2011).
assessment that models this phase

PR2C3_D5C (C–Pr)

Id: phase:c-pr:pr2c3-d5c; status assigned
Structure: Pu2C3 · D5_c · cI40 · I-43d (220); type st:d5-c-pu2c3-ci40; tier A: standard phase name; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 300–1821.15 K, x(C) 0.54404–0.6
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-pr:pr2c3-d5c
tdb: tdb:PrC-11Pen.tdb:PR2C3_D5C

TDB models of PR2C3_D5C (1): PHASE and CONSTITUENT statements as written

PrC-11Pen.tdb: PR2C3_D5C, type code %, sha256 7207a325d93d7b08…

56: PHASE PR2C3_D5C % 2 2 3 !
57: CONST PR2C3_D5C : PR : C% VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.09.002 Yingbiao Peng, Yong Du, Lijun Zhang, Chunsheng Sha, Shuhong Liu, Feng Zheng et al., Thermodynamic modeling of the C–RE (RE=La, Ce and Pr) systems, Calphad 35, 533-541 (2011).
assessment that models this phase

PRC2_BETA (C–Pr)

Id: phase:c-pr:prc2-beta; status assigned
Structure: CaC2 · cF36 · Fm-3m (225); type st:cac2-cf36; 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_structure_token, off_stoichiometric_model); structure as stated in the SGTE crystallographic table for this phase name and system
Stability: stable in 1 of 1 calculated diagram(s): 1427.43–2589.18 K, x(C) 0.65795–0.66612
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-pr:prc2-beta
tdb: tdb:PrC-11Pen.tdb:PRC2_BETA

TDB models of PRC2_BETA (1): PHASE and CONSTITUENT statements as written

PrC-11Pen.tdb: PRC2_BETA, type code %, sha256 7207a325d93d7b08…

66: PHASE PRC2_BETA % 2 1 2 !
67: CONST PRC2_BETA : PR : C% VA : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.09.002 Yingbiao Peng, Yong Du, Lijun Zhang, Chunsheng Sha, Shuhong Liu, Feng Zheng et al., Thermodynamic modeling of the C–RE (RE=La, Ce and Pr) systems, Calphad 35, 533-541 (2011).
assessment that models this phase

PRC2_C11A (C–Pr)

Id: phase:c-pr:prc2-c11a; status assigned
Structure: CaC2 · C11_a · tI6 · I4/mmm (139); type st:c11-a-cac2-ti6; tier A: standard phase name; confidence high
Stoichiometry: C 0.6667, Pr 0.3333
Stability: stable in 1 of 1 calculated diagram(s): 300–1413.6 K, x(C) 0.66667–0.66667
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:c-pr:prc2-c11a
tdb: tdb:PrC-11Pen.tdb:PRC2_C11A

TDB models of PRC2_C11A (1): PHASE and CONSTITUENT statements as written

PrC-11Pen.tdb: PRC2_C11A, type code %, sha256 7207a325d93d7b08…

61: PHASE PRC2_C11A % 2 1 2 !
62: CONST PRC2_C11A : PR : C : !

Example references (1 of 1; assessments first):

doi:10.1016/j.calphad.2011.09.002 Yingbiao Peng, Yong Du, Lijun Zhang, Chunsheng Sha, Shuhong Liu, Feng Zheng et al., Thermodynamic modeling of the C–RE (RE=La, Ce and Pr) systems, Calphad 35, 533-541 (2011).
assessment that models this phase

Please cite

R. Arróyave, J. Saal, D. Shin, ORCHID-Registry: phase registry of binary systems (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23735970
R. Arróyave, J. Saal, D. Shin, ORCHID data: umbrella record of the ORCHID datasets (version 2026.10; Version 1, machine-extracted), Zenodo (2026). doi:10.5281/zenodo.23736065

Also cite B. Hallstedt, The SGTE collection of binary datasets, Calphad 89 (2025) 102833, https://doi.org/10.1016/j.calphad.2025.102833 (CC BY 4.0), and the original assessment named in each file; A. Jain et al., The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002, https://doi.org/10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501, https://doi.org/10.1007/s11837-013-0755-4 and S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010, https://doi.org/10.1038/npjcompumats.2015.10 (CC BY 4.0); the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work). Version 1, machine-extracted: values were read by language-model readers constrained to quote their source and checked automatically, and the release was then audited on the printed pages by adversarial audits, an independent second review of fit-facing records and a preliminary human review of a frozen sample. Flags such as accepted and ESPEI-ready record screening results, not certification; known issues are listed in the release notes.

@misc{orchid_phase_registry_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID-Registry: phase registry of binary systems}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23735970},
  url       = {https://doi.org/10.5281/zenodo.23735970},
  note      = {Version 1, machine-extracted}
}

@misc{orchid_data_2026,
  author    = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon},
  title     = {{ORCHID data: umbrella record of the ORCHID datasets}},
  version   = {2026.10},
  publisher = {Zenodo},
  year      = {2026},
  doi       = {10.5281/zenodo.23736065},
  url       = {https://doi.org/10.5281/zenodo.23736065},
  note      = {Version 1, machine-extracted}
}