Ca–O phases

9 phases (tier A 4, liquid 2, gas 2, needs_review 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 · Ca–O system page · Markdown · field reference

Phases of the Ca–O system (9)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
B1_OXIDE phase:ca-o:b1-oxide	NaCl · B1 · cF8 · Fm-3m (225)	tier A: standard phase name	stable in 4 of 4 calculated diagram(s): 300–2500 K, x(O) 0.5–0.5	18	4
BCC_A2 phase:ca-o:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	stable in 4 of 4 calculated diagram(s): 716.03–1168 K, x(O) 0–0	0	4
CAO2_C11A phase:ca-o:cao2-c11a		needs_review	stable in 1 of 3 calculated diagram(s): 300–335 K, x(O) 0.66667–0.66667	0	3
FCC_A1 phase:ca-o:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 3 of 4 calculated diagram(s): 300–716.03 K, x(O) 0–0	0	4
GAS phase:ca-o:gas	gas	gas	stable in 4 of 4 calculated diagram(s): 1347.5–2500 K, x(O) 0–1	0	4
HCP_A3 phase:ca-o:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 4 calculated diagram(s)	0	4
ION phase:ca-o:ion	liquid	liquid	stable in 4 of 4 calculated diagram(s): 1100–1809.06 K, x(O) 0–0.07372	0	4
LIQUID phase:ca-o:liquid	liquid	liquid	not stable in 4 calculated diagram(s)	19	4
O2GAS phase:ca-o:o2gas	gas	gas	stable in 4 of 4 calculated diagram(s): 300–1077.5 K, x(O) 1–1	0	4

B1_OXIDE (Ca–O)

Id: phase:ca-o:b1-oxide; status assigned
Structure: NaCl · B1 · cF8 · Fm-3m (225); type st:b1-nacl-cf8; tier A: standard phase name; confidence high
Stability: stable in 4 of 4 calculated diagram(s): 300–2500 K, x(O) 0.5–0.5
Literature: 18 values (18 accepted) from 1 papers
Interactive: phase registry entry

Names (6): corpus: corpus:phase:ca-o:b1-oxide
paper: paper:10.1016/j.jeurceramsoc.2018.06.015:CaO
tdb: tdb:CaO-18Lia.tdb:B1_OXIDE, tdb:CaO-20Def-3g.tdb:B1_OXIDE, tdb:CaO-23Abd-3g.tdb:B1_OXIDE, tdb:CaO-96Sel.tdb:B1_OXIDE

TDB models of B1_OXIDE (4): PHASE and CONSTITUENT statements as written

CaO-18Lia.tdb: B1_OXIDE, type code %, sha256 78618178a1324682…

59: PHASE B1_OXIDE:I % 2 1 1 !
60: CONST B1_OXIDE:I : CA+2 : O-2 : !

CaO-20Def-3g.tdb: B1_OXIDE, type code %, sha256 2df29e5f285a88c6…

65: PHASE B1_OXIDE:I % 2 1 1 !
66: CONST B1_OXIDE:I : CA+2 : O-2 : !

CaO-23Abd-3g.tdb: B1_OXIDE, type code %, sha256 c6509b3e8c06ae7f…

67: PHASE B1_OXIDE:I % 2 1 1 !
68: CONST B1_OXIDE:I : CA+2 : O-2 : !

CaO-96Sel.tdb: B1_OXIDE, type code %, sha256 c26a22ca6d938a23…

56: PHASE B1_OXIDE:I % 2 1 1 !
57: CONST B1_OXIDE:I : CA+2 : O-2 : !

Example references (10 of 12; assessments first):

doi:10.1016/j.jeurceramsoc.2018.06.015 Song-Mao Liang, Rainer Schmid-Fetzer, Complete thermodynamic description of the Mg-Ca-O phase diagram including the Ca-O, Mg-O and CaO-MgO subsystems, Journal of the European Ceramic Society 38, 4768-4785 (2018).
assessment that models this phase; reports values for this phase
doi:10.1016/j.calphad.2020.101764 Guillaume Deffrennes, Noël Jakse, Cecilia M.S. Alvares, Ioana Nuta, Alain Pasturel, Alexandra Khvan et al., Thermodynamic modelling of the Ca–O system including 3rd generation description of CaO and CaO2, Calphad 69, 101764 (2020).
assessment that models this phase
doi:10.1016/j.cemconres.2023.107309 Wahab Abdul, Chancel Mawalala, Alexander Pisch, Marcus Nigel Bannerman, CaO-SiO2 assessment using 3rd generation CALPHAD models, Cement and Concrete Research 173, 107309 (2023).
assessment that models this phase
doi:10.1016/S0364-5916(96)00039-9 M. Selleby, B. Sundman, Calphad, 20, 391-92(1996).
assessment that models this phase
doi:10.1007/bf02880517 H.A. Wriedt, The Ca−O (Calcium-Oxygen) system, Bull. Alloy Phase Diagrams 6 (1985) 337–342, http://dx.doi.org/10.1007/BF02880517.
cited as the source of values for this phase
doi:10.1351/pac198254030681 J. Hlavac, Melting temperatures of refractory oxides: Part I, Pure and Applied Chemistry 54, 681-688 (1982).
cited as the source of values for this phase
doi:10.1016/0016-7037(87)90009-3 Milton Blander, Arthur D. Pelton, Thermodynamic analysis of binary liquid silicates and prediction of ternary solution properties by modified quasichemical equations, Geochimica et Cosmochimica Acta 51, 85-95 (1987).
cited as the source of values for this phase
doi:10.1016/0038-092x(65)90162-3 Marc Foex, Measurement of the solidification points of several refractory oxides by means of a solar furnace, Solar Energy 9, 61-67 (1965).
cited as the source of values for this phase
doi:10.1016/0038-092x(67)90022-9 Tetsuo Noguchi, Masao Mizuno, William M. Conn, Fundamental research in refractory system with a solar furnace—ZrO2CaO system, Solar Energy 11, 145-152 (1967).
cited as the source of values for this phase
doi:10.1016/0364-5916(89)90006-0 M. Hillert, X. Wang, Thermodynamic calculation of the CaO–MgO system, Calphad 13 (1989) 267–271, http://dx.doi.org/10.1016/0364-5916(89)90006-0.
cited as the source of values for this phase

BCC_A2 (Ca–O)

Id: phase:ca-o: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 4 of 4 calculated diagram(s): 716.03–1168 K, x(O) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:ca-o:bcc-a2
tdb: tdb:CaO-18Lia.tdb:BCC_A2, tdb:CaO-20Def-3g.tdb:BCC_A2, tdb:CaO-23Abd-3g.tdb:BCC_A2, tdb:CaO-96Sel.tdb:BCC_A2

TDB models of BCC_A2 (4): PHASE and CONSTITUENT statements as written

CaO-18Lia.tdb: BCC_A2, type code %B, sha256 78618178a1324682…

49: PHASE BCC_A2 %B 2 1 3 !
50: CONST BCC_A2 : CA% O : VA : !

CaO-20Def-3g.tdb: BCC_A2, type code %B, sha256 2df29e5f285a88c6…

55: PHASE BCC_A2 %B 2 1 3 !
56: CONST BCC_A2 : CA% O : VA : !

CaO-23Abd-3g.tdb: BCC_A2, type code %B, sha256 c6509b3e8c06ae7f…

57: PHASE BCC_A2 %B 2 1 3 !
58: CONST BCC_A2 : CA% O : VA : !

CaO-96Sel.tdb: BCC_A2, type code %B, sha256 c26a22ca6d938a23…

46: PHASE BCC_A2 %B 2 1 3 !
47: CONST BCC_A2 : CA : VA : !

Example references (4 of 4; assessments first):

doi:10.1016/j.calphad.2020.101764 Guillaume Deffrennes, Noël Jakse, Cecilia M.S. Alvares, Ioana Nuta, Alain Pasturel, Alexandra Khvan et al., Thermodynamic modelling of the Ca–O system including 3rd generation description of CaO and CaO2, Calphad 69, 101764 (2020).
assessment that models this phase
doi:10.1016/j.cemconres.2023.107309 Wahab Abdul, Chancel Mawalala, Alexander Pisch, Marcus Nigel Bannerman, CaO-SiO2 assessment using 3rd generation CALPHAD models, Cement and Concrete Research 173, 107309 (2023).
assessment that models this phase
doi:10.1016/j.jeurceramsoc.2018.06.015 Song-Mao Liang, Rainer Schmid-Fetzer, Complete thermodynamic description of the Mg-Ca-O phase diagram including the Ca-O, Mg-O and CaO-MgO subsystems, Journal of the European Ceramic Society 38, 4768-4785 (2018).
assessment that models this phase
doi:10.1016/S0364-5916(96)00039-9 M. Selleby, B. Sundman, Calphad, 20, 391-92(1996).
assessment that models this phase

CAO2_C11A (Ca–O)

Id: phase:ca-o:cao2-c11a; status needs_review
No structure assigned. Why: assessment_declared_blocked_by:site_ratios_contradict_C11_a; site_ratios_contradict_C11_a:CaO-18Lia.tdb; site_ratios_contradict_C11_a:CaO-20Def-3g.tdb; site_ratios_contradict_C11_a:CaO-23Abd-3g.tdb
Candidate (name_token): CaC2 · C11_a · tI6 · I4/mmm (139) — Strukturbericht/word 'C11A' in the TDB name
Candidate (sgte_mmc2): CaC2 · C11_a · tI6 · I4/mmm (139) — Hallstedt 2025 mmc2 row for CAO2_C11A: CaO2 (peroxide)
Candidate (tdb_comment): CaC2 · tI6 · I4/mmm — CaO-18Lia.tdb: 'Prototype CaC2 (tI6, I4/mmm), C11_a, barium peroxide'
Candidate (tdb_comment): CaC2 · tI6 · I4/mmm — CaO-20Def-3g.tdb: 'Prototype CaC2 (tI6, I4/mmm), C11_a, barium peroxide'
Candidate (tdb_comment): CaC2 · tI6 · I4/mmm — CaO-23Abd-3g.tdb: 'Prototype CaC2 (tI6, I4/mmm), C11_a, barium peroxide'
Stability: stable in 1 of 3 calculated diagram(s): 300–335 K, x(O) 0.66667–0.66667
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:ca-o:cao2-c11a
tdb: tdb:CaO-18Lia.tdb:CAO2_C11A, tdb:CaO-20Def-3g.tdb:CAO2_C11A, tdb:CaO-23Abd-3g.tdb:CAO2_C11A

TDB models of CAO2_C11A (3): PHASE and CONSTITUENT statements as written

CaO-18Lia.tdb: CAO2_C11A, type code %, sha256 78618178a1324682…

64: PHASE CAO2_C11A:I % 2 1 1 !
65: CONST CAO2_C11A:I : CA+2 : O2-2 : !

CaO-20Def-3g.tdb: CAO2_C11A, type code %, sha256 2df29e5f285a88c6…

70: PHASE CAO2_C11A:I % 2 1 1 !
71: CONST CAO2_C11A:I : CA+2 : O2-2 : !

CaO-23Abd-3g.tdb: CAO2_C11A, type code %, sha256 c6509b3e8c06ae7f…

72: PHASE CAO2_C11A:I % 2 1 1 !
73: CONST CAO2_C11A:I : CA+2 : O2-2 : !

Example references (3 of 3; assessments first):

doi:10.1016/j.calphad.2020.101764 Guillaume Deffrennes, Noël Jakse, Cecilia M.S. Alvares, Ioana Nuta, Alain Pasturel, Alexandra Khvan et al., Thermodynamic modelling of the Ca–O system including 3rd generation description of CaO and CaO2, Calphad 69, 101764 (2020).
assessment that models this phase
doi:10.1016/j.cemconres.2023.107309 Wahab Abdul, Chancel Mawalala, Alexander Pisch, Marcus Nigel Bannerman, CaO-SiO2 assessment using 3rd generation CALPHAD models, Cement and Concrete Research 173, 107309 (2023).
assessment that models this phase
doi:10.1016/j.jeurceramsoc.2018.06.015 Song-Mao Liang, Rainer Schmid-Fetzer, Complete thermodynamic description of the Mg-Ca-O phase diagram including the Ca-O, Mg-O and CaO-MgO subsystems, Journal of the European Ceramic Society 38, 4768-4785 (2018).
assessment that models this phase

FCC_A1 (Ca–O)

Id: phase:ca-o: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 3 of 4 calculated diagram(s): 300–716.03 K, x(O) 0–0
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:ca-o:fcc-a1
tdb: tdb:CaO-18Lia.tdb:FCC_A1, tdb:CaO-20Def-3g.tdb:FCC_A1, tdb:CaO-23Abd-3g.tdb:FCC_A1, tdb:CaO-96Sel.tdb:FCC_A1

TDB models of FCC_A1 (4): PHASE and CONSTITUENT statements as written

CaO-18Lia.tdb: FCC_A1, type code %A, sha256 78618178a1324682…

44: PHASE FCC_A1 %A 2 1 1 !
45: CONST FCC_A1 : CA% O : VA : !

CaO-20Def-3g.tdb: FCC_A1, type code %A, sha256 2df29e5f285a88c6…

50: PHASE FCC_A1 %A 2 1 1 !
51: CONST FCC_A1 : CA% O : VA : !

CaO-23Abd-3g.tdb: FCC_A1, type code %A, sha256 c6509b3e8c06ae7f…

52: PHASE FCC_A1 %A 2 1 1 !
53: CONST FCC_A1 : CA% O : VA : !

CaO-96Sel.tdb: FCC_A1, type code %A, sha256 c26a22ca6d938a23…

41: PHASE FCC_A1 %A 2 1 1 !
42: CONST FCC_A1 : CA : VA : !

Example references (4 of 4; assessments first):

doi:10.1016/j.calphad.2020.101764 Guillaume Deffrennes, Noël Jakse, Cecilia M.S. Alvares, Ioana Nuta, Alain Pasturel, Alexandra Khvan et al., Thermodynamic modelling of the Ca–O system including 3rd generation description of CaO and CaO2, Calphad 69, 101764 (2020).
assessment that models this phase
doi:10.1016/j.cemconres.2023.107309 Wahab Abdul, Chancel Mawalala, Alexander Pisch, Marcus Nigel Bannerman, CaO-SiO2 assessment using 3rd generation CALPHAD models, Cement and Concrete Research 173, 107309 (2023).
assessment that models this phase
doi:10.1016/j.jeurceramsoc.2018.06.015 Song-Mao Liang, Rainer Schmid-Fetzer, Complete thermodynamic description of the Mg-Ca-O phase diagram including the Ca-O, Mg-O and CaO-MgO subsystems, Journal of the European Ceramic Society 38, 4768-4785 (2018).
assessment that models this phase
doi:10.1016/S0364-5916(96)00039-9 M. Selleby, B. Sundman, Calphad, 20, 391-92(1996).
assessment that models this phase

GAS (Ca–O)

Id: phase:ca-o:gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 4 of 4 calculated diagram(s): 1347.5–2500 K, x(O) 0–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:ca-o:gas
tdb: tdb:CaO-18Lia.tdb:GAS, tdb:CaO-20Def-3g.tdb:GAS, tdb:CaO-23Abd-3g.tdb:GAS, tdb:CaO-96Sel.tdb:GAS

TDB models of GAS (4): PHASE and CONSTITUENT statements as written

CaO-18Lia.tdb: GAS, type code %, sha256 78618178a1324682…

67: PHASE GAS:G % 1 1 !
68: CONST GAS:G : CA CA2 CAO O O2% O3 : !

CaO-20Def-3g.tdb: GAS, type code %, sha256 2df29e5f285a88c6…

73: PHASE GAS:G % 1 1 !
74: CONST GAS:G : CA CA2 CAO O O2% O3 : !

CaO-23Abd-3g.tdb: GAS, type code %, sha256 c6509b3e8c06ae7f…

75: PHASE GAS:G % 1 1 !
76: CONST GAS:G : CA CA2 CAO O O2% O3 : !

CaO-96Sel.tdb: GAS, type code %, sha256 c26a22ca6d938a23…

59: PHASE GAS:G % 1 1 !
60: CONST GAS:G : CA CA2 CAO O O2% O3 : !

Example references (4 of 4; assessments first):

doi:10.1016/j.calphad.2020.101764 Guillaume Deffrennes, Noël Jakse, Cecilia M.S. Alvares, Ioana Nuta, Alain Pasturel, Alexandra Khvan et al., Thermodynamic modelling of the Ca–O system including 3rd generation description of CaO and CaO2, Calphad 69, 101764 (2020).
assessment that models this phase
doi:10.1016/j.cemconres.2023.107309 Wahab Abdul, Chancel Mawalala, Alexander Pisch, Marcus Nigel Bannerman, CaO-SiO2 assessment using 3rd generation CALPHAD models, Cement and Concrete Research 173, 107309 (2023).
assessment that models this phase
doi:10.1016/j.jeurceramsoc.2018.06.015 Song-Mao Liang, Rainer Schmid-Fetzer, Complete thermodynamic description of the Mg-Ca-O phase diagram including the Ca-O, Mg-O and CaO-MgO subsystems, Journal of the European Ceramic Society 38, 4768-4785 (2018).
assessment that models this phase
doi:10.1016/S0364-5916(96)00039-9 M. Selleby, B. Sundman, Calphad, 20, 391-92(1996).
assessment that models this phase

HCP_A3 (Ca–O)

Id: phase:ca-o: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 4 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:ca-o:hcp-a3
tdb: tdb:CaO-18Lia.tdb:HCP_A3, tdb:CaO-20Def-3g.tdb:HCP_A3, tdb:CaO-23Abd-3g.tdb:HCP_A3, tdb:CaO-96Sel.tdb:HCP_A3

TDB models of HCP_A3 (4): PHASE and CONSTITUENT statements as written

CaO-18Lia.tdb: HCP_A3, type code %A, sha256 78618178a1324682…

54: PHASE HCP_A3 %A 2 1 0.5 !
55: CONST HCP_A3 : CA O : VA : !

CaO-20Def-3g.tdb: HCP_A3, type code %A, sha256 2df29e5f285a88c6…

60: PHASE HCP_A3 %A 2 1 0.5 !
61: CONST HCP_A3 : CA O : VA : !

CaO-23Abd-3g.tdb: HCP_A3, type code %A, sha256 c6509b3e8c06ae7f…

62: PHASE HCP_A3 %A 2 1 0.5 !
63: CONST HCP_A3 : CA O : VA : !

CaO-96Sel.tdb: HCP_A3, type code %A, sha256 c26a22ca6d938a23…

51: PHASE HCP_A3 %A 2 1 0.5 !
52: CONST HCP_A3 : CA : VA : !

Example references (4 of 4; assessments first):

doi:10.1016/j.calphad.2020.101764 Guillaume Deffrennes, Noël Jakse, Cecilia M.S. Alvares, Ioana Nuta, Alain Pasturel, Alexandra Khvan et al., Thermodynamic modelling of the Ca–O system including 3rd generation description of CaO and CaO2, Calphad 69, 101764 (2020).
assessment that models this phase
doi:10.1016/j.cemconres.2023.107309 Wahab Abdul, Chancel Mawalala, Alexander Pisch, Marcus Nigel Bannerman, CaO-SiO2 assessment using 3rd generation CALPHAD models, Cement and Concrete Research 173, 107309 (2023).
assessment that models this phase
doi:10.1016/j.jeurceramsoc.2018.06.015 Song-Mao Liang, Rainer Schmid-Fetzer, Complete thermodynamic description of the Mg-Ca-O phase diagram including the Ca-O, Mg-O and CaO-MgO subsystems, Journal of the European Ceramic Society 38, 4768-4785 (2018).
assessment that models this phase
doi:10.1016/S0364-5916(96)00039-9 M. Selleby, B. Sundman, Calphad, 20, 391-92(1996).
assessment that models this phase

ION (Ca–O)

Id: phase:ca-o:ion; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 4 of 4 calculated diagram(s): 1100–1809.06 K, x(O) 0–0.07372
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:ca-o:ion
tdb: tdb:CaO-18Lia.tdb:ION, tdb:CaO-20Def-3g.tdb:ION, tdb:CaO-23Abd-3g.tdb:ION, tdb:CaO-96Sel.tdb:ION

TDB models of ION (4): PHASE and CONSTITUENT statements as written

CaO-18Lia.tdb: ION, type code %, sha256 78618178a1324682…

36: PHASE ION:Y % 2 1 1 !
37: CONST ION:Y : CA+2 : O-2 VA O : !

CaO-20Def-3g.tdb: ION, type code %, sha256 2df29e5f285a88c6…

42: PHASE ION:Y % 2 1 1 !
43: CONST ION:Y : CA+2 : O-2 VA O : !

CaO-23Abd-3g.tdb: ION, type code %, sha256 c6509b3e8c06ae7f…

44: PHASE ION:Y % 2 1 1 !
45: CONST ION:Y : CA+2 : O-2 VA O : !

CaO-96Sel.tdb: ION, type code %, sha256 c26a22ca6d938a23…

33: PHASE ION:Y % 2 1 1 !
34: CONST ION:Y : CA+2 : O-2 VA : !

Example references (4 of 4; assessments first):

doi:10.1016/j.calphad.2020.101764 Guillaume Deffrennes, Noël Jakse, Cecilia M.S. Alvares, Ioana Nuta, Alain Pasturel, Alexandra Khvan et al., Thermodynamic modelling of the Ca–O system including 3rd generation description of CaO and CaO2, Calphad 69, 101764 (2020).
assessment that models this phase
doi:10.1016/j.cemconres.2023.107309 Wahab Abdul, Chancel Mawalala, Alexander Pisch, Marcus Nigel Bannerman, CaO-SiO2 assessment using 3rd generation CALPHAD models, Cement and Concrete Research 173, 107309 (2023).
assessment that models this phase
doi:10.1016/j.jeurceramsoc.2018.06.015 Song-Mao Liang, Rainer Schmid-Fetzer, Complete thermodynamic description of the Mg-Ca-O phase diagram including the Ca-O, Mg-O and CaO-MgO subsystems, Journal of the European Ceramic Society 38, 4768-4785 (2018).
assessment that models this phase
doi:10.1016/S0364-5916(96)00039-9 M. Selleby, B. Sundman, Calphad, 20, 391-92(1996).
assessment that models this phase

LIQUID (Ca–O)

Id: phase:ca-o:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: not stable in 4 calculated diagram(s)
Literature: 19 values (19 accepted) from 1 papers
Interactive: phase registry entry

Names (6): corpus: corpus:phase:ca-o:liquid
paper: paper:10.1016/j.jeurceramsoc.2018.06.015:liquid
tdb: tdb:CaO-18Lia.tdb:LIQUID, tdb:CaO-20Def-3g.tdb:LIQUID, tdb:CaO-23Abd-3g.tdb:LIQUID, tdb:CaO-96Sel.tdb:LIQUID

TDB models of LIQUID (4): PHASE and CONSTITUENT statements as written

CaO-18Lia.tdb: LIQUID, type code %, sha256 78618178a1324682…

39: PHASE LIQUID:L % 1 1 !
40: CONST LIQUID:L : CA CAO O : !

CaO-20Def-3g.tdb: LIQUID, type code %, sha256 2df29e5f285a88c6…

45: PHASE LIQUID:L % 1 1 !
46: CONST LIQUID:L : CA CAO O : !

CaO-23Abd-3g.tdb: LIQUID, type code %, sha256 c6509b3e8c06ae7f…

47: PHASE LIQUID:L % 1 1 !
48: CONST LIQUID:L : CA CAO O : !

CaO-96Sel.tdb: LIQUID, type code %, sha256 c26a22ca6d938a23…

36: PHASE LIQUID:L % 1 1 !
37: CONST LIQUID:L : CA : !

Example references (10 of 12; assessments first):

doi:10.1016/j.jeurceramsoc.2018.06.015 Song-Mao Liang, Rainer Schmid-Fetzer, Complete thermodynamic description of the Mg-Ca-O phase diagram including the Ca-O, Mg-O and CaO-MgO subsystems, Journal of the European Ceramic Society 38, 4768-4785 (2018).
assessment that models this phase; reports values for this phase
doi:10.1016/j.calphad.2020.101764 Guillaume Deffrennes, Noël Jakse, Cecilia M.S. Alvares, Ioana Nuta, Alain Pasturel, Alexandra Khvan et al., Thermodynamic modelling of the Ca–O system including 3rd generation description of CaO and CaO2, Calphad 69, 101764 (2020).
assessment that models this phase
doi:10.1016/j.cemconres.2023.107309 Wahab Abdul, Chancel Mawalala, Alexander Pisch, Marcus Nigel Bannerman, CaO-SiO2 assessment using 3rd generation CALPHAD models, Cement and Concrete Research 173, 107309 (2023).
assessment that models this phase
doi:10.1016/S0364-5916(96)00039-9 M. Selleby, B. Sundman, Calphad, 20, 391-92(1996).
assessment that models this phase
doi:10.1007/bf02880517 H.A. Wriedt, The Ca−O (Calcium-Oxygen) system, Bull. Alloy Phase Diagrams 6 (1985) 337–342, http://dx.doi.org/10.1007/BF02880517.
cited as the source of values for this phase
doi:10.1351/pac198254030681 J. Hlavac, Melting temperatures of refractory oxides: Part I, Pure and Applied Chemistry 54, 681-688 (1982).
cited as the source of values for this phase
doi:10.1016/0016-7037(87)90009-3 Milton Blander, Arthur D. Pelton, Thermodynamic analysis of binary liquid silicates and prediction of ternary solution properties by modified quasichemical equations, Geochimica et Cosmochimica Acta 51, 85-95 (1987).
cited as the source of values for this phase
doi:10.1016/0038-092x(65)90162-3 Marc Foex, Measurement of the solidification points of several refractory oxides by means of a solar furnace, Solar Energy 9, 61-67 (1965).
cited as the source of values for this phase
doi:10.1016/0038-092x(67)90022-9 Tetsuo Noguchi, Masao Mizuno, William M. Conn, Fundamental research in refractory system with a solar furnace—ZrO2CaO system, Solar Energy 11, 145-152 (1967).
cited as the source of values for this phase
doi:10.1016/0364-5916(89)90006-0 M. Hillert, X. Wang, Thermodynamic calculation of the CaO–MgO system, Calphad 13 (1989) 267–271, http://dx.doi.org/10.1016/0364-5916(89)90006-0.
cited as the source of values for this phase

O2GAS (Ca–O)

Id: phase:ca-o:o2gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 4 of 4 calculated diagram(s): 300–1077.5 K, x(O) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:ca-o:o2gas
tdb: tdb:CaO-18Lia.tdb:O2GAS, tdb:CaO-20Def-3g.tdb:O2GAS, tdb:CaO-23Abd-3g.tdb:O2GAS, tdb:CaO-96Sel.tdb:O2GAS

TDB models of O2GAS (4): PHASE and CONSTITUENT statements as written

CaO-18Lia.tdb: O2GAS, type code %, sha256 78618178a1324682…

70: PHASE O2GAS % 1 1 !
71: CONST O2GAS : O2 : !

CaO-20Def-3g.tdb: O2GAS, type code %, sha256 2df29e5f285a88c6…

76: PHASE O2GAS % 1 1 !
77: CONST O2GAS : O2 : !

CaO-23Abd-3g.tdb: O2GAS, type code %, sha256 c6509b3e8c06ae7f…

78: PHASE O2GAS % 1 1 !
79: CONST O2GAS : O2 : !

CaO-96Sel.tdb: O2GAS, type code %, sha256 c26a22ca6d938a23…

62: PHASE O2GAS % 1 1 !
63: CONST O2GAS : O2 : !

Example references (4 of 4; assessments first):

doi:10.1016/j.calphad.2020.101764 Guillaume Deffrennes, Noël Jakse, Cecilia M.S. Alvares, Ioana Nuta, Alain Pasturel, Alexandra Khvan et al., Thermodynamic modelling of the Ca–O system including 3rd generation description of CaO and CaO2, Calphad 69, 101764 (2020).
assessment that models this phase
doi:10.1016/j.cemconres.2023.107309 Wahab Abdul, Chancel Mawalala, Alexander Pisch, Marcus Nigel Bannerman, CaO-SiO2 assessment using 3rd generation CALPHAD models, Cement and Concrete Research 173, 107309 (2023).
assessment that models this phase
doi:10.1016/j.jeurceramsoc.2018.06.015 Song-Mao Liang, Rainer Schmid-Fetzer, Complete thermodynamic description of the Mg-Ca-O phase diagram including the Ca-O, Mg-O and CaO-MgO subsystems, Journal of the European Ceramic Society 38, 4768-4785 (2018).
assessment that models this phase
doi:10.1016/S0364-5916(96)00039-9 M. Selleby, B. Sundman, Calphad, 20, 391-92(1996).
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}
}