Cu–S phases

14 phases (tier A 4, tier B 1, liquid 2, gas 1, needs_review 6); 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 · full JSON · Cu–S system page · Markdown · field reference

Phases of the Cu–S system (14)
Phase	Structure	Basis	Stability (calculated)	Literature values	TDB models
ORTHORHOMBIC_A16 phase:cu-s:a16-orthorhombic	alpha-S · A16 · oF128 · Fddd (70)	tier A: standard phase name	stable in 3 of 3 calculated diagram(s): 300–2499.34 K, x(S) 1–1	0	3
BCC_A2 phase:cu-s:bcc-a2	W · A2 · cI2 · Im-3m (229)	tier A: standard phase name	not stable in 3 calculated diagram(s)	0	3
CU2S_ALPHA phase:cu-s:cu2s-alpha		needs_review	stable in 3 of 3 calculated diagram(s): 300–379.45 K, x(S) 0.33333–0.33333	0	3
CU2S_BETA phase:cu-s:cu2s-beta		needs_review	stable in 3 of 3 calculated diagram(s): 375.97–710.93 K, x(S) 0.33333–0.33333	0	3
CU2S_GAMMA phase:cu-s:cu2s-gamma		needs_review	stable in 3 of 3 calculated diagram(s): 325.41–1411.55 K, x(S) 0.33301–0.36861	0	3
CU31S16 phase:cu-s:cu31s16		needs_review	stable in 3 of 3 calculated diagram(s): 300–371.96 K, x(S) 0.3413–0.3413	0	3
CU7S4 phase:cu-s:cu7s4	Cu7S4 · oP44 · Pnma (62)	tier B: DFT-supported (unique MP + OQMD match)	stable in 3 of 3 calculated diagram(s): 300–350.02 K, x(S) 0.36364–0.36364	0	3
CUS_B18 phase:cu-s:cus-b18		needs_review	stable in 3 of 3 calculated diagram(s): 300–779.75 K, x(S) 0.5–0.5	0	3
FCC_A1 phase:cu-s:fcc-a1	Cu · A1 · cF4 · Fm-3m (225)	tier A: standard phase name	stable in 3 of 3 calculated diagram(s): 300–1357.77 K, x(S) 0–0.00023	0	3
GAS phase:cu-s:gas	gas	gas	stable in 1 of 1 calculated diagram(s): 723.86–2500 K, x(S) 0.96162–1	0	1
HCP_A3 phase:cu-s:hcp-a3	Mg · A3 · hP2 · P6_3/mmc (194)	tier A: standard phase name	not stable in 3 calculated diagram(s)	0	3
ION phase:cu-s:ion	liquid	liquid	stable in 2 of 2 calculated diagram(s): 1314–2328.03 K, x(S) 0–0.33391	0	2
LIQUID phase:cu-s:liquid	liquid	liquid	stable in 3 of 3 calculated diagram(s): 384.34–2500 K, x(S) 0–1	3	3
MONOCLINIC_S phase:cu-s:s-monoclinic		needs_review	stable in 1 of 3 calculated diagram(s): 368.33–2499.6 K, x(S) 1–1	0	3

ORTHORHOMBIC_A16 (Cu–S)

Id: phase:cu-s:a16-orthorhombic; status assigned
Structure: alpha-S · A16 · oF128 · Fddd (70); type st:a16-alpha-s-of128; tier A: standard phase name; confidence high
Stoichiometry: S 1.0000
Stability: stable in 3 of 3 calculated diagram(s): 300–2499.34 K, x(S) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-s:a16-orthorhombic
tdb: tdb:CuS-07Lee.tdb:ORTHORHOMBIC_A16, tdb:CuS-92Sun-LB.tdb:ORTHORHOMBIC_A16, tdb:CuS-92Sun-newS.tdb:ORTHORHOMBIC_A16

TDB models of ORTHORHOMBIC_A16 (3): PHASE and CONSTITUENT statements as written

CuS-07Lee.tdb: ORTHORHOMBIC_A16, type code %, sha256 d5d1065a84e9aabe…

56: PHASE ORTHORHOMBIC_A16 % 1 1 !
57: CONST ORTHORHOMBIC_A16 : S : !

CuS-92Sun-LB.tdb: ORTHORHOMBIC_A16, type code %, sha256 b8d5ff92c7cc3e83…

55: PHASE ORTHORHOMBIC_A16 % 1 1 !
56: CONST ORTHORHOMBIC_A16 : S : !

CuS-92Sun-newS.tdb: ORTHORHOMBIC_A16, type code %, sha256 137242d5bf305aad…

62: PHASE ORTHORHOMBIC_A16 % 1 1 !
63: CONST ORTHORHOMBIC_A16 : S : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase

BCC_A2 (Cu–S)

Id: phase:cu-s:bcc-a2; status assigned
Structure: W · A2 · cI2 · Im-3m (229); type st:a2-w-ci2; tier A: standard phase name; confidence high
Stability: not stable in 3 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-s:bcc-a2
tdb: tdb:CuS-07Lee.tdb:BCC_A2, tdb:CuS-92Sun-LB.tdb:BCC_A2, tdb:CuS-92Sun-newS.tdb:BCC_A2

TDB models of BCC_A2 (3): PHASE and CONSTITUENT statements as written

CuS-07Lee.tdb: BCC_A2, type code %B, sha256 d5d1065a84e9aabe…

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

CuS-92Sun-LB.tdb: BCC_A2, type code %B, sha256 b8d5ff92c7cc3e83…

45: PHASE BCC_A2 %B 2 1 3 !
46: CONST BCC_A2 : CU S : VA : !

CuS-92Sun-newS.tdb: BCC_A2, type code %B, sha256 137242d5bf305aad…

52: PHASE BCC_A2 %B 2 1 3 !
53: CONST BCC_A2 : CU S : VA : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase

CU2S_ALPHA (Cu–S)

Id: phase:cu-s:cu2s-alpha; status needs_review
No structure assigned. Why: no_structure_token; polymorph_family:other phases of this system have the same composition
Candidate (sgte_mmc2): Cu2S-alpha · mP144 · P2_1/c (14) — Hallstedt 2025 mmc2 row for CU2S_ALPHA: Cu2S-alpha (alpha-chalcopyrite)
Candidate (tdb_comment): alpha-Cu2S · mP144 · P2_1/c — CuS-07Lee.tdb: 'Prototype alpha-Cu2S (mP144, P2_1/c), alpha-chalcopyrite'
Candidate (tdb_comment): alpha-Cu2S · mP144 · P2_1/c — CuS-92Sun-LB.tdb: 'Prototype alpha-Cu2S (mP144, P2_1/c), alpha-chalcopyrite'
Candidate (tdb_comment): alpha-Cu2S · mP144 · P2_1/c — CuS-92Sun-newS.tdb: 'Prototype alpha-Cu2S (mP144, P2_1/c), alpha-chalcopyrite'
Stoichiometry: Cu 0.6667, S 0.3333
Stability: stable in 3 of 3 calculated diagram(s): 300–379.45 K, x(S) 0.33333–0.33333
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-s:cu2s-alpha
tdb: tdb:CuS-07Lee.tdb:CU2S_ALPHA, tdb:CuS-92Sun-LB.tdb:CU2S_ALPHA, tdb:CuS-92Sun-newS.tdb:CU2S_ALPHA

TDB models of CU2S_ALPHA (3): PHASE and CONSTITUENT statements as written

CuS-07Lee.tdb: CU2S_ALPHA, type code %, sha256 d5d1065a84e9aabe…

66: PHASE CU2S_ALPHA % 2 2 1 !
67: CONST CU2S_ALPHA : CU : S : !

CuS-92Sun-LB.tdb: CU2S_ALPHA, type code %, sha256 b8d5ff92c7cc3e83…

65: PHASE CU2S_ALPHA % 2 2 1 !
66: CONST CU2S_ALPHA : CU : S : !

CuS-92Sun-newS.tdb: CU2S_ALPHA, type code %, sha256 137242d5bf305aad…

72: PHASE CU2S_ALPHA % 2 2 1 !
73: CONST CU2S_ALPHA : CU : S : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase

CU2S_BETA (Cu–S)

Id: phase:cu-s:cu2s-beta; status needs_review
No structure assigned. Why: no_structure_token; polymorph_family:other phases of this system have the same composition
Candidate (sgte_mmc2): Cu2S-beta · hP16 · P6_3/mmc (194) — Hallstedt 2025 mmc2 row for CU2S_BETA: Cu2S-beta (beta-chalcopyrite)
Candidate (tdb_comment): — CuS-07Lee.tdb: 'Prototype InNi2 (B8_2) according to LB-binary'
Candidate (tdb_comment): beta-Cu2S · hP16 · P6_3/mmc — CuS-07Lee.tdb: 'Prototype beta-Cu2S (hP16, P6_3/mmc), beta-chalcopyrite'
Candidate (tdb_comment): — CuS-92Sun-LB.tdb: 'Prototype InNi2 (B8_2) according to LB-binary'
Candidate (tdb_comment): beta-Cu2S · hP16 · P6_3/mmc — CuS-92Sun-LB.tdb: 'Prototype beta-Cu2S (hP16, P6_3/mmc), beta-chalcopyrite'
Candidate (tdb_comment): — CuS-92Sun-newS.tdb: 'Prototype InNi2 (B8_2) according to LB-binary'
Candidate (tdb_comment): beta-Cu2S · hP16 · P6_3/mmc — CuS-92Sun-newS.tdb: 'Prototype beta-Cu2S (hP16, P6_3/mmc), beta-chalcopyrite'
Stoichiometry: Cu 0.6667, S 0.3333
Stability: stable in 3 of 3 calculated diagram(s): 375.97–710.93 K, x(S) 0.33333–0.33333
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-s:cu2s-beta
tdb: tdb:CuS-07Lee.tdb:CU2S_BETA, tdb:CuS-92Sun-LB.tdb:CU2S_BETA, tdb:CuS-92Sun-newS.tdb:CU2S_BETA

TDB models of CU2S_BETA (3): PHASE and CONSTITUENT statements as written

CuS-07Lee.tdb: CU2S_BETA, type code %, sha256 d5d1065a84e9aabe…

72: PHASE CU2S_BETA % 2 2 1 !
73: CONST CU2S_BETA : CU : S : !

CuS-92Sun-LB.tdb: CU2S_BETA, type code %, sha256 b8d5ff92c7cc3e83…

71: PHASE CU2S_BETA % 2 2 1 !
72: CONST CU2S_BETA : CU : S : !

CuS-92Sun-newS.tdb: CU2S_BETA, type code %, sha256 137242d5bf305aad…

78: PHASE CU2S_BETA % 2 2 1 !
79: CONST CU2S_BETA : CU : S : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase

CU2S_GAMMA (Cu–S)

Id: phase:cu-s:cu2s-gamma; status needs_review
No structure assigned. Why: no_structure_token; off_stoichiometric_model
Candidate (dft_mp): Pnma (62) — on-hull MP Cu7S4 at x(S)=0.3636
Candidate (dft_oqmd): Pnma (62) — on-hull OQMD Cu7 S4 at x(S)=0.3636
Candidate (sgte_mmc2): Cu2Se-beta · cF44 · Fm-3m (225) — Hallstedt 2025 mmc2 row for CU2S_GAMMA: Cu2S-gamma (digenite)
Candidate (tdb_comment): — CuS-07Lee.tdb: 'Prototype CaF2 according to LB-binary'
Candidate (tdb_comment): Cu2Se · cF44 · Fm-3m — CuS-07Lee.tdb: 'Prototype Cu2Se (cF44, Fm-3m), digenite'
Candidate (tdb_comment): — CuS-92Sun-LB.tdb: 'Prototype CaF2 according to LB-binary'
Candidate (tdb_comment): Cu2Se · cF44 · Fm-3m — CuS-92Sun-LB.tdb: 'Prototype Cu2Se (cF44, Fm-3m), digenite'
Candidate (tdb_comment): — CuS-92Sun-newS.tdb: 'Prototype CaF2 according to LB-binary'
Stability: stable in 3 of 3 calculated diagram(s): 325.41–1411.55 K, x(S) 0.33301–0.36861
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-s:cu2s-gamma
tdb: tdb:CuS-07Lee.tdb:CU2S_GAMMA, tdb:CuS-92Sun-LB.tdb:CU2S_GAMMA, tdb:CuS-92Sun-newS.tdb:CU2S_GAMMA

TDB models of CU2S_GAMMA (3): PHASE and CONSTITUENT statements as written

CuS-07Lee.tdb: CU2S_GAMMA, type code %, sha256 d5d1065a84e9aabe…

78: PHASE CU2S_GAMMA % 3 2 1 1 !
79: CONST CU2S_GAMMA : CU VA : CU VA : S : !

CuS-92Sun-LB.tdb: CU2S_GAMMA, type code %, sha256 b8d5ff92c7cc3e83…

77: PHASE CU2S_GAMMA % 3 2 1 1 !
78: CONST CU2S_GAMMA : CU VA : CU VA : S : !

CuS-92Sun-newS.tdb: CU2S_GAMMA, type code %, sha256 137242d5bf305aad…

84: PHASE CU2S_GAMMA % 3 2 1 1 !
85: CONST CU2S_GAMMA : CU VA : CU VA : S : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase

CU31S16 (Cu–S)

Id: phase:cu-s:cu31s16; status needs_review
No structure assigned. Why: assessment_declared_compound_differs_from_model_composition; no_on_hull_entry_in_both; no_structure_token
Candidate (sgte_mmc2): Cu31S16 · mP376 · P2_1/c (14) — Hallstedt 2025 mmc2 row for CU31S16: Cu31S16 (djurleite)
Candidate (tdb_comment): Cu31S16 · mP376 · P2_1/c — CuS-07Lee.tdb: 'Prototype Cu31S16 (mP376, P2_1/c), djurleite'
Candidate (tdb_comment): Cu31S16 · mP376 · P2_1/c — CuS-92Sun-LB.tdb: 'Prototype Cu31S16 (mP376, P2_1/c), djurleite'
Candidate (tdb_comment): Cu31S16 · mP376 · P2_1/c — CuS-92Sun-newS.tdb: 'Prototype Cu31S16 (mP376, P2_1/c), djurleite'
Stoichiometry: Cu 0.6587, S 0.3413
Stability: stable in 3 of 3 calculated diagram(s): 300–371.96 K, x(S) 0.3413–0.3413
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-s:cu31s16
tdb: tdb:CuS-07Lee.tdb:CU31S16, tdb:CuS-92Sun-LB.tdb:CU31S16, tdb:CuS-92Sun-newS.tdb:CU31S16

TDB models of CU31S16 (3): PHASE and CONSTITUENT statements as written

CuS-07Lee.tdb: CU31S16, type code %, sha256 d5d1065a84e9aabe…

83: PHASE CU31S16 % 2 1.93 1 !
84: CONST CU31S16 : CU : S : !

CuS-92Sun-LB.tdb: CU31S16, type code %, sha256 b8d5ff92c7cc3e83…

82: PHASE CU31S16 % 2 1.93 1 !
83: CONST CU31S16 : CU : S : !

CuS-92Sun-newS.tdb: CU31S16, type code %, sha256 137242d5bf305aad…

89: PHASE CU31S16 % 2 1.93 1 !
90: CONST CU31S16 : CU : S : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase

CU7S4 (Cu–S)

Id: phase:cu-s:cu7s4; status assigned
Structure: Cu7S4 · oP44 · Pnma (62); type st:cu7s4-op44; tier B: DFT-supported (unique MP + OQMD match); confidence high
Stoichiometry: Cu 0.6364, S 0.3636
Stability: stable in 3 of 3 calculated diagram(s): 300–350.02 K, x(S) 0.36364–0.36364
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (6): corpus: corpus:phase:cu-s:cu7s4
mp: mp:mp-aaabjnnn
oqmd: oqmd:oqmd-36981
tdb: tdb:CuS-07Lee.tdb:CU7S4, tdb:CuS-92Sun-LB.tdb:CU7S4, tdb:CuS-92Sun-newS.tdb:CU7S4

TDB models of CU7S4 (3): PHASE and CONSTITUENT statements as written

CuS-07Lee.tdb: CU7S4, type code %, sha256 d5d1065a84e9aabe…

88: PHASE CU7S4 % 2 1.75 1 !
89: CONST CU7S4 : CU : S : !

CuS-92Sun-LB.tdb: CU7S4, type code %, sha256 b8d5ff92c7cc3e83…

87: PHASE CU7S4 % 2 1.75 1 !
88: CONST CU7S4 : CU : S : !

CuS-92Sun-newS.tdb: CU7S4, type code %, sha256 137242d5bf305aad…

94: PHASE CU7S4 % 2 1.75 1 !
95: CONST CU7S4 : CU : S : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase

CUS_B18 (Cu–S)

Id: phase:cu-s:cus-b18; status needs_review
No structure assigned. Why: assessment_declared_blocked_by:name_suggests_B18_but_dft_space_group_63; name_suggests_B18_but_dft_space_group_63
Candidate (dft_mp): Cmcm (63) — on-hull MP CuS at x(S)=0.5000
Candidate (dft_oqmd): Cmcm (63) — on-hull OQMD Cu1 S1 at x(S)=0.5000
Candidate (name_token): CuS · B18 · hP12 · P6_3/mmc (194) — Strukturbericht/word 'B18' in the TDB name
Candidate (sgte_mmc2): CuS · B18 · hP12 · P6_3/mmc (194) — Hallstedt 2025 mmc2 row for CUS_B18: CuS (covellite)
Candidate (tdb_comment): CuS · hP12 · P6_3/mmc — CuS-07Lee.tdb: 'Prototype CuS (hP12, P6_3/mmc), covellite'
Candidate (tdb_comment): CuS · hP12 · P6_3/mmc — CuS-92Sun-LB.tdb: 'Prototype CuS (hP12, P6_3/mmc), covellite'
Candidate (tdb_comment): CuS · hP12 · P6_3/mmc — CuS-92Sun-newS.tdb: 'Prototype CuS (hP12, P6_3/mmc), covellite'
Stoichiometry: Cu 0.5000, S 0.5000
Stability: stable in 3 of 3 calculated diagram(s): 300–779.75 K, x(S) 0.5–0.5
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-s:cus-b18
tdb: tdb:CuS-07Lee.tdb:CUS_B18, tdb:CuS-92Sun-LB.tdb:CUS_B18, tdb:CuS-92Sun-newS.tdb:CUS_B18

TDB models of CUS_B18 (3): PHASE and CONSTITUENT statements as written

CuS-07Lee.tdb: CUS_B18, type code %, sha256 d5d1065a84e9aabe…

93: PHASE CUS_B18 % 2 1 1 !
94: CONST CUS_B18 : CU : S : !

CuS-92Sun-LB.tdb: CUS_B18, type code %, sha256 b8d5ff92c7cc3e83…

92: PHASE CUS_B18 % 2 1 1 !
93: CONST CUS_B18 : CU : S : !

CuS-92Sun-newS.tdb: CUS_B18, type code %, sha256 137242d5bf305aad…

99: PHASE CUS_B18 % 2 1 1 !
100: CONST CUS_B18 : CU : S : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase

FCC_A1 (Cu–S)

Id: phase:cu-s: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 3 calculated diagram(s): 300–1357.77 K, x(S) 0–0.00023
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-s:fcc-a1
tdb: tdb:CuS-07Lee.tdb:FCC_A1, tdb:CuS-92Sun-LB.tdb:FCC_A1, tdb:CuS-92Sun-newS.tdb:FCC_A1

TDB models of FCC_A1 (3): PHASE and CONSTITUENT statements as written

CuS-07Lee.tdb: FCC_A1, type code %A, sha256 d5d1065a84e9aabe…

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

CuS-92Sun-LB.tdb: FCC_A1, type code %A, sha256 b8d5ff92c7cc3e83…

40: PHASE FCC_A1 %A 2 1 1 !
41: CONST FCC_A1 : CU S : VA : !

CuS-92Sun-newS.tdb: FCC_A1, type code %A, sha256 137242d5bf305aad…

47: PHASE FCC_A1 %A 2 1 1 !
48: CONST FCC_A1 : CU S : VA : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase

GAS (Cu–S)

Id: phase:cu-s:gas; status assigned
Structure: gas; type st:gas; gas; confidence high
Stability: stable in 1 of 1 calculated diagram(s): 723.86–2500 K, x(S) 0.96162–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (2): corpus: corpus:phase:cu-s:gas
tdb: tdb:CuS-07Lee.tdb:GAS

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

CuS-07Lee.tdb: GAS, type code %, sha256 d5d1065a84e9aabe…

96: PHASE GAS:G % 1 1 !
97: CONST GAS:G : CU CU2 CU2S CUS S S2 S3 S4 S5 S6 S7 S8 : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase

HCP_A3 (Cu–S)

Id: phase:cu-s: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: Cu 1.0000
Stability: not stable in 3 calculated diagram(s)
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-s:hcp-a3
tdb: tdb:CuS-07Lee.tdb:HCP_A3, tdb:CuS-92Sun-LB.tdb:HCP_A3, tdb:CuS-92Sun-newS.tdb:HCP_A3

TDB models of HCP_A3 (3): PHASE and CONSTITUENT statements as written

CuS-07Lee.tdb: HCP_A3, type code %A, sha256 d5d1065a84e9aabe…

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

CuS-92Sun-LB.tdb: HCP_A3, type code %A, sha256 b8d5ff92c7cc3e83…

50: PHASE HCP_A3 %A 2 1 0.5 !
51: CONST HCP_A3 : CU : VA : !

CuS-92Sun-newS.tdb: HCP_A3, type code %A, sha256 137242d5bf305aad…

57: PHASE HCP_A3 %A 2 1 0.5 !
58: CONST HCP_A3 : CU : VA : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase

ION (Cu–S)

Id: phase:cu-s:ion; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 2 of 2 calculated diagram(s): 1314–2328.03 K, x(S) 0–0.33391
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (3): corpus: corpus:phase:cu-s:ion
tdb: tdb:CuS-92Sun-LB.tdb:ION, tdb:CuS-92Sun-newS.tdb:ION

TDB models of ION (2): PHASE and CONSTITUENT statements as written

CuS-92Sun-LB.tdb: ION, type code %, sha256 b8d5ff92c7cc3e83…

35: PHASE ION:Y % 2 1 1 !
36: CONST ION:Y : CU+1 CU+2 : S-2 VA S : !

CuS-92Sun-newS.tdb: ION, type code %, sha256 137242d5bf305aad…

42: PHASE ION:Y % 2 1 1 !
43: CONST ION:Y : CU+1 CU+2 : S-2 VA S : !

LIQUID (Cu–S)

Id: phase:cu-s:liquid; status assigned
Structure: liquid; type st:liquid; liquid; confidence high
Stability: stable in 3 of 3 calculated diagram(s): 384.34–2500 K, x(S) 0–1
Literature: 3 values (2 accepted) from 1 papers
Interactive: phase registry entry

Names (5): corpus: corpus:phase:cu-s:liquid
paper: paper:10.2355/isijinternational.47.163:L
tdb: tdb:CuS-07Lee.tdb:LIQUID, tdb:CuS-92Sun-LB.tdb:LIQUID, tdb:CuS-92Sun-newS.tdb:LIQUID

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

CuS-07Lee.tdb: LIQUID, type code %, sha256 d5d1065a84e9aabe…

36: PHASE LIQUID:L % 1 1 !
37: CONST LIQUID:L : CU CU2S S : !

CuS-92Sun-LB.tdb: LIQUID, type code %, sha256 b8d5ff92c7cc3e83…

32: PHASE LIQUID:L % 1 1 !
33: CONST LIQUID:L : CU S : !

CuS-92Sun-newS.tdb: LIQUID, type code %, sha256 137242d5bf305aad…

39: PHASE LIQUID:L % 1 1 !
40: CONST LIQUID:L : CU S : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
assessment that models this phase; reports values for this phase

MONOCLINIC_S (Cu–S)

Id: phase:cu-s:s-monoclinic; status needs_review
No structure assigned. Why: name_has_descriptive_tokens:MONOCLINIC; no_structure_token
Candidate (sgte_mmc2): beta-S · mP48 · P2_1/c (14) — Hallstedt 2025 mmc2 row for MONOCLINIC_S: beta-S
Candidate (tdb_comment): beta-S · mP48 · P2_1/a — CuS-07Lee.tdb: 'Prototype beta-S (mP48, P2_1/a)'
Candidate (tdb_comment): beta-S · mP48 · P2_1/a — CuS-92Sun-LB.tdb: 'Prototype beta-S (mP48, P2_1/a)'
Candidate (tdb_comment): beta-S · mP48 · P2_1/a — CuS-92Sun-newS.tdb: 'Prototype beta-S (mP48, P2_1/a)'
Stoichiometry: S 1.0000
Stability: stable in 1 of 3 calculated diagram(s): 368.33–2499.6 K, x(S) 1–1
Literature: 0 values (0 accepted) from 0 papers
Interactive: phase registry entry

Names (4): corpus: corpus:phase:cu-s:s-monoclinic
tdb: tdb:CuS-07Lee.tdb:MONOCLINIC_S, tdb:CuS-92Sun-LB.tdb:MONOCLINIC_S, tdb:CuS-92Sun-newS.tdb:MONOCLINIC_S

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

CuS-07Lee.tdb: MONOCLINIC_S, type code %, sha256 d5d1065a84e9aabe…

61: PHASE MONOCLINIC_S % 1 1 !
62: CONST MONOCLINIC_S : S : !

CuS-92Sun-LB.tdb: MONOCLINIC_S, type code %, sha256 b8d5ff92c7cc3e83…

60: PHASE MONOCLINIC_S % 1 1 !
61: CONST MONOCLINIC_S : S : !

CuS-92Sun-newS.tdb: MONOCLINIC_S, type code %, sha256 137242d5bf305aad…

67: PHASE MONOCLINIC_S % 1 1 !
68: CONST MONOCLINIC_S : S : !

Example references (1 of 1; assessments first):

doi:10.2355/isijinternational.47.163 Byeong-Joo Lee, Bo Sundman, Sung Il Kim, Kwang-Geun Chin, Thermodynamic Calculations on the Stability of Cu2S in Low Carbon Steels, ISIJ Int. 47, 163-171 (2007).
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}
}