Co–Si phases
10 phases (tier A 8, liquid 1, needs_review 1); 9 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 · Co–Si system page · Markdown · field reference
| Phase | Structure | Basis | Stability (calculated) | Literature values | TDB models |
|---|---|---|---|---|---|
| DIAMOND_A4 phase:co-si:a4-diamond | C (diamond) · A4 · cF8 · Fd-3m (227) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 300–1687 K, x(Si) 1–1 | 5 | 2 |
| BCC_A2 phase:co-si:bcc-a2 | W · A2 · cI2 · Im-3m (229) | tier A: standard phase name | not stable in 2 calculated diagram(s) | 0 | 2 |
| CO2SI_BETA phase:co-si:co2si-beta | needs_review | stable in 1 of 1 calculated diagram(s): 1512.3–1594.25 K, x(Si) 0.33337–0.34652 | 13 | 1 | |
| CO2SI_C37 phase:co-si:co2si-c37 | Co2Si · C37 · oP12 · Pnma (62) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 300–1603.68 K, x(Si) 0.32229–0.33776 | 26 | 2 |
| CO3SI_D019 phase:co-si:co3si-d019 | Ni3Sn · D0_19 · hP8 · P6_3/mmc (194) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 1467.38–1500 K, x(Si) 0.25–0.25 | 17 | 2 |
| COSI_B20 phase:co-si:cosi-b20 | FeSi · B20 · cP8 · P2_13 (198) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 300–1729.38 K, x(Si) 0.49115–0.51491 | 26 | 2 |
| COSI2_C1 phase:co-si:cosi2-c1 | CaF2 · C1 · cF12 · Fm-3m (225) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 300–1596.91 K, x(Si) 0.66667–0.66667 | 23 | 2 |
| FCC_A1 phase:co-si:fcc-a1 | Cu · A1 · cF4 · Fm-3m (225) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 687.99–2500 K, x(Si) 0–0.74075 | 5 | 2 |
| HCP_A3 phase:co-si:hcp-a3 | Mg · A3 · hP2 · P6_3/mmc (194) | tier A: standard phase name | stable in 2 of 2 calculated diagram(s): 300–1963.38 K, x(Si) 0–0.69033 | 15 | 2 |
| LIQUID phase:co-si:liquid | liquid | liquid | stable in 2 of 2 calculated diagram(s): 1475.55–2500 K, x(Si) 0–1 | 51 | 2 |
DIAMOND_A4 (Co–Si)
- Id:
phase:co-si:a4-diamond; statusassigned - Structure: C (diamond) · A4 · cF8 · Fd-3m (227); type
st:a4-c-diamond-cf8; tier A: standard phase name; confidence high - Stoichiometry: Si 1.0000
- Stability: stable in 2 of 2 calculated diagram(s): 300–1687 K, x(Si) 1–1
- Literature: 5 values (5 accepted) from 2 papers
- Interactive: phase registry entry
Names (6): corpus: corpus:phase:co-si:a4-diamond, corpus:phase:co-si:diamond-a4
paper: paper:10.1016/0364-5916(92)90003-g:Si, paper:10.1016/j.calphad.2006.06.001:(Si)
tdb: tdb:CoSi-06Zha.tdb:DIAMOND_A4, tdb:CoSi-92Cho-LB.tdb:DIAMOND_A4
TDB models of DIAMOND_A4 (2): PHASE and CONSTITUENT statements as written
CoSi-06Zha.tdb: DIAMOND_A4, type code %, sha256 849716b03f938610…
43: PHASE DIAMOND_A4 % 1 1 ! 44: CONST DIAMOND_A4 : SI : !
CoSi-92Cho-LB.tdb: DIAMOND_A4, type code %, sha256 9fb5aa520ab17aa5…
49: PHASE DIAMOND_A4 % 1 1 ! 50: CONST DIAMOND_A4 : SI : !
Example references (3 of 3; assessments first):
- doi:10.1016/j.calphad.2006.06.001 Lijun Zhang, Yong Du, Honghui Xu, Zhu Pan, Experimental investigation and thermodynamic description of the Co–Si system, Calphad 30, 470-481 (2006).
assessment that models this phase; reports values for this phase - doi:10.1016/0364-5916(92)90003-G S.-D. Choi, Calphad, 16, 151-59(1992).
assessment that models this phase; reports values for this phase - doi:10.2320/jinstmet1937.1.3_135 Uichi Haschimoto, The Equilibrium Diagram of the Cobalt-Silicon system, J.Japan Inst.Metals 1, 135-143 (1937).
cited as the source of values for this phase
BCC_A2 (Co–Si)
- Id:
phase:co-si:bcc-a2; statusassigned - Structure: W · A2 · cI2 · Im-3m (229); type
st:a2-w-ci2; tier A: standard phase name; confidence high - Stability: not stable in 2 calculated diagram(s)
- Literature: 0 values (0 accepted) from 0 papers
- Interactive: phase registry entry
Names (3): corpus: corpus:phase:co-si:bcc-a2
tdb: tdb:CoSi-06Zha.tdb:BCC_A2, tdb:CoSi-92Cho-LB.tdb:BCC_A2
TDB models of BCC_A2 (2): PHASE and CONSTITUENT statements as written
CoSi-06Zha.tdb: BCC_A2, type code %B, sha256 849716b03f938610…
33: PHASE BCC_A2 %B 2 1 3 ! 34: CONST BCC_A2 : CO SI : VA : !
CoSi-92Cho-LB.tdb: BCC_A2, type code %B, sha256 9fb5aa520ab17aa5…
39: PHASE BCC_A2 %B 2 1 3 ! 40: CONST BCC_A2 : CO SI : VA : !
Example references (2 of 2; assessments first):
- doi:10.1016/0364-5916(92)90003-G S.-D. Choi, Calphad, 16, 151-59(1992).
assessment that models this phase - doi:10.1016/j.calphad.2006.06.001 Lijun Zhang, Yong Du, Honghui Xu, Zhu Pan, Experimental investigation and thermodynamic description of the Co–Si system, Calphad 30, 470-481 (2006).
assessment that models this phase
CO2SI_BETA (Co–Si)
- Id:
phase:co-si:co2si-beta; statusneeds_review - No structure assigned. Why: no_structure_token; off_stoichiometric_model; sgte_mmc2_row_incomplete
- Candidate (sgte_mmc2): (Co2Si) — Hallstedt 2025 mmc2 row for CO2SI_BETA: beta-Co2Si
- Stability: stable in 1 of 1 calculated diagram(s): 1512.3–1594.25 K, x(Si) 0.33337–0.34652
- Literature: 13 values (13 accepted) from 1 papers
- Interactive: phase registry entry
Names (3): corpus: corpus:phase:co-si:co2si-beta
paper: paper:10.1016/j.calphad.2006.06.001:βCo2Si
tdb: tdb:CoSi-06Zha.tdb:CO2SI_BETA
TDB models of CO2SI_BETA (1): PHASE and CONSTITUENT statements as written
CoSi-06Zha.tdb: CO2SI_BETA, type code %, sha256 849716b03f938610…
58: PHASE CO2SI_BETA % 2 2 1 ! 59: CONST CO2SI_BETA : CO% SI : CO SI% : !
Example references (4 of 4; assessments first):
- doi:10.1016/j.calphad.2006.06.001 Lijun Zhang, Yong Du, Honghui Xu, Zhu Pan, Experimental investigation and thermodynamic description of the Co–Si system, Calphad 30, 470-481 (2006).
assessment that models this phase; reports values for this phase - doi:10.1002/srin.193400094 Rudolf Vogel, Kurt Rosenthal, Das Zustandsschaubild Kobalt-Silizium, Archiv für das Eisenhüttenwesen 7, 689-691 (1934).
cited as the source of values for this phase - doi:10.2320/jinstmet1937.1.3_135 Uichi Haschimoto, The Equilibrium Diagram of the Cobalt-Silicon system, J.Japan Inst.Metals 1, 135-143 (1937).
cited as the source of values for this phase - doi:10.1007/bf02645074 K Ishida, T Nishizawa, M. E Schlesinger, The Co-Si (Cobalt-Silicon) system, JPE 12, 578-586 (1991).
cited as the source of values for this phase
CO2SI_C37 (Co–Si)
- Id:
phase:co-si:co2si-c37; statusassigned - Structure: Co2Si · C37 · oP12 · Pnma (62); type
st:c37-co2si-op12; tier A: standard phase name; confidence high - Caveat: partitioned order/disorder model in CoSi-06Zha.tdb also describes the disordered state
- Stability: stable in 2 of 2 calculated diagram(s): 300–1603.68 K, x(Si) 0.32229–0.33776
- Literature: 26 values (24 accepted) from 2 papers
- Interactive: phase registry entry
Names (5): corpus: corpus:phase:co-si:co2si-c37
paper: paper:10.1016/0364-5916(92)90003-g:Co2Si, paper:10.1016/j.calphad.2006.06.001:αCo2Si
tdb: tdb:CoSi-06Zha.tdb:CO2SI_C37, tdb:CoSi-92Cho-LB.tdb:CO2SI_C37
TDB models of CO2SI_C37 (2): PHASE and CONSTITUENT statements as written
CoSi-06Zha.tdb: CO2SI_C37, type code %, sha256 849716b03f938610…
53: PHASE CO2SI_C37 % 2 2 1 ! 54: CONST CO2SI_C37 : CO% SI : CO SI% : !
CoSi-92Cho-LB.tdb: CO2SI_C37, type code %, sha256 9fb5aa520ab17aa5…
59: PHASE CO2SI_C37 % 2 2 1 ! 60: CONST CO2SI_C37 : CO : SI : !
Example references (6 of 6; assessments first):
- doi:10.1016/j.calphad.2006.06.001 Lijun Zhang, Yong Du, Honghui Xu, Zhu Pan, Experimental investigation and thermodynamic description of the Co–Si system, Calphad 30, 470-481 (2006).
assessment that models this phase; reports values for this phase - doi:10.1016/0364-5916(92)90003-G S.-D. Choi, Calphad, 16, 151-59(1992).
assessment that models this phase; reports values for this phase - doi:10.1002/srin.193400094 Rudolf Vogel, Kurt Rosenthal, Das Zustandsschaubild Kobalt-Silizium, Archiv für das Eisenhüttenwesen 7, 689-691 (1934).
cited as the source of values for this phase - doi:10.2320/jinstmet1937.1.3_135 Uichi Haschimoto, The Equilibrium Diagram of the Cobalt-Silicon system, J.Japan Inst.Metals 1, 135-143 (1937).
cited as the source of values for this phase - doi:10.1007/bf02645074 K Ishida, T Nishizawa, M. E Schlesinger, The Co-Si (Cobalt-Silicon) system, JPE 12, 578-586 (1991).
cited as the source of values for this phase - doi:10.1016/0001-6160(72)90001-6 J Van Den Boomgaard, F.M.A Carpay, The eutectoid Co3Si phase in the Co-Si system, Acta Metallurgica 20, 473-476 (1972).
cited as the source of values for this phase
CO3SI_D019 (Co–Si)
- Id:
phase:co-si:co3si-d019; statusassigned - Structure: Ni3Sn · D0_19 · hP8 · P6_3/mmc (194); type
st:d0-19-ni3sn-hp8; tier A: standard phase name; confidence high - Stoichiometry: Co 0.7500, Si 0.2500
- Stability: stable in 2 of 2 calculated diagram(s): 1467.38–1500 K, x(Si) 0.25–0.25
- Literature: 17 values (17 accepted) from 2 papers
- Interactive: phase registry entry
Names (5): corpus: corpus:phase:co-si:co3si-d019
paper: paper:10.1016/0364-5916(92)90003-g:Co3Si, paper:10.1016/j.calphad.2006.06.001:αCo3Si
tdb: tdb:CoSi-06Zha.tdb:CO3SI_D019, tdb:CoSi-92Cho-LB.tdb:CO3SI_D019
TDB models of CO3SI_D019 (2): PHASE and CONSTITUENT statements as written
CoSi-06Zha.tdb: CO3SI_D019, type code %, sha256 849716b03f938610…
48: PHASE CO3SI_D019 % 2 3 1 ! 49: CONST CO3SI_D019 : CO : SI : !
CoSi-92Cho-LB.tdb: CO3SI_D019, type code %, sha256 9fb5aa520ab17aa5…
54: PHASE CO3SI_D019 % 2 3 1 ! 55: CONST CO3SI_D019 : CO : SI : !
Example references (5 of 5; assessments first):
- doi:10.1016/j.calphad.2006.06.001 Lijun Zhang, Yong Du, Honghui Xu, Zhu Pan, Experimental investigation and thermodynamic description of the Co–Si system, Calphad 30, 470-481 (2006).
assessment that models this phase; reports values for this phase - doi:10.1016/0364-5916(92)90003-G S.-D. Choi, Calphad, 16, 151-59(1992).
assessment that models this phase; reports values for this phase - doi:10.1002/srin.193400094 Rudolf Vogel, Kurt Rosenthal, Das Zustandsschaubild Kobalt-Silizium, Archiv für das Eisenhüttenwesen 7, 689-691 (1934).
cited as the source of values for this phase - doi:10.1016/0001-6160(72)90001-6 J Van Den Boomgaard, F.M.A Carpay, The eutectoid Co3Si phase in the Co-Si system, Acta Metallurgica 20, 473-476 (1972).
cited as the source of values for this phase - doi:10.2320/jinstmet1937.1.3_135 Uichi Haschimoto, The Equilibrium Diagram of the Cobalt-Silicon system, J.Japan Inst.Metals 1, 135-143 (1937).
cited as the source of values for this phase
COSI_B20 (Co–Si)
- Id:
phase:co-si:cosi-b20; statusassigned - Structure: FeSi · B20 · cP8 · P2_13 (198); type
st:b20-fesi-cp8; tier A: standard phase name; confidence high - Caveat: partitioned order/disorder model in CoSi-06Zha.tdb also describes the disordered state
- Stability: stable in 2 of 2 calculated diagram(s): 300–1729.38 K, x(Si) 0.49115–0.51491
- Literature: 26 values (24 accepted) from 2 papers
- Interactive: phase registry entry
Names (5): corpus: corpus:phase:co-si:cosi-b20
paper: paper:10.1016/0364-5916(92)90003-g:CoSi, paper:10.1016/j.calphad.2006.06.001:CoSi
tdb: tdb:CoSi-06Zha.tdb:COSI_B20, tdb:CoSi-92Cho-LB.tdb:COSI_B20
TDB models of COSI_B20 (2): PHASE and CONSTITUENT statements as written
CoSi-06Zha.tdb: COSI_B20, type code %, sha256 849716b03f938610…
63: PHASE COSI_B20 % 2 1 1 ! 64: CONST COSI_B20 : CO% SI : CO SI% : !
CoSi-92Cho-LB.tdb: COSI_B20, type code %, sha256 9fb5aa520ab17aa5…
64: PHASE COSI_B20 % 2 1 1 ! 65: CONST COSI_B20 : CO : SI : !
Example references (4 of 4; assessments first):
- doi:10.1016/j.calphad.2006.06.001 Lijun Zhang, Yong Du, Honghui Xu, Zhu Pan, Experimental investigation and thermodynamic description of the Co–Si system, Calphad 30, 470-481 (2006).
assessment that models this phase; reports values for this phase - doi:10.1016/0364-5916(92)90003-G S.-D. Choi, Calphad, 16, 151-59(1992).
assessment that models this phase; reports values for this phase - doi:10.2320/jinstmet1937.1.3_135 Uichi Haschimoto, The Equilibrium Diagram of the Cobalt-Silicon system, J.Japan Inst.Metals 1, 135-143 (1937).
cited as the source of values for this phase - doi:10.1002/srin.193400094 Rudolf Vogel, Kurt Rosenthal, Das Zustandsschaubild Kobalt-Silizium, Archiv für das Eisenhüttenwesen 7, 689-691 (1934).
cited as the source of values for this phase
COSI2_C1 (Co–Si)
- Id:
phase:co-si:cosi2-c1; statusassigned - Structure: CaF2 · C1 · cF12 · Fm-3m (225); type
st:c1-caf2-cf12; tier A: standard phase name; confidence high - Caveat: DFT agrees: on-hull mp-aaaaadnn and oqmd-5256, space group 225
- Stoichiometry: Co 0.3333, Si 0.6667
- Stability: stable in 2 of 2 calculated diagram(s): 300–1596.91 K, x(Si) 0.66667–0.66667
- Literature: 23 values (21 accepted) from 2 papers
- Interactive: phase registry entry
Names (7): corpus: corpus:phase:co-si:cosi2-c1
mp: mp:mp-aaaaadnn
oqmd: oqmd:oqmd-5256
paper: paper:10.1016/0364-5916(92)90003-g:CoSi2, paper:10.1016/j.calphad.2006.06.001:CoSi2
tdb: tdb:CoSi-06Zha.tdb:COSI2_C1, tdb:CoSi-92Cho-LB.tdb:COSI2_C1
TDB models of COSI2_C1 (2): PHASE and CONSTITUENT statements as written
CoSi-06Zha.tdb: COSI2_C1, type code %, sha256 849716b03f938610…
68: PHASE COSI2_C1 % 2 1 2 ! 69: CONST COSI2_C1 : CO : SI : !
CoSi-92Cho-LB.tdb: COSI2_C1, type code %, sha256 9fb5aa520ab17aa5…
69: PHASE COSI2_C1 % 2 1 2 ! 70: CONST COSI2_C1 : CO : SI : !
Example references (3 of 3; assessments first):
- doi:10.1016/j.calphad.2006.06.001 Lijun Zhang, Yong Du, Honghui Xu, Zhu Pan, Experimental investigation and thermodynamic description of the Co–Si system, Calphad 30, 470-481 (2006).
assessment that models this phase; reports values for this phase - doi:10.1016/0364-5916(92)90003-G S.-D. Choi, Calphad, 16, 151-59(1992).
assessment that models this phase; reports values for this phase - doi:10.2320/jinstmet1937.1.3_135 Uichi Haschimoto, The Equilibrium Diagram of the Cobalt-Silicon system, J.Japan Inst.Metals 1, 135-143 (1937).
cited as the source of values for this phase
FCC_A1 (Co–Si)
- Id:
phase:co-si:fcc-a1; statusassigned - Structure: Cu · A1 · cF4 · Fm-3m (225); type
st:a1-cu-cf4; tier A: standard phase name; confidence high - Stability: stable in 2 of 2 calculated diagram(s): 687.99–2500 K, x(Si) 0–0.74075
- Literature: 5 values (5 accepted) from 2 papers
- Interactive: phase registry entry
Names (5): corpus: corpus:phase:co-si:fcc-a1
paper: paper:10.1016/0364-5916(92)90003-g:α-Co, paper:10.1016/j.calphad.2006.06.001:(αCo)
tdb: tdb:CoSi-06Zha.tdb:FCC_A1, tdb:CoSi-92Cho-LB.tdb:FCC_A1
TDB models of FCC_A1 (2): PHASE and CONSTITUENT statements as written
CoSi-06Zha.tdb: FCC_A1, type code %A, sha256 849716b03f938610…
28: PHASE FCC_A1 %A 2 1 1 ! 29: CONST FCC_A1 : CO SI : VA : !
CoSi-92Cho-LB.tdb: FCC_A1, type code %A, sha256 9fb5aa520ab17aa5…
34: PHASE FCC_A1 %A 2 1 1 ! 35: CONST FCC_A1 : CO SI : VA : !
Example references (2 of 2; assessments first):
- doi:10.1016/j.calphad.2006.06.001 Lijun Zhang, Yong Du, Honghui Xu, Zhu Pan, Experimental investigation and thermodynamic description of the Co–Si system, Calphad 30, 470-481 (2006).
assessment that models this phase; reports values for this phase - doi:10.1016/0364-5916(92)90003-G S.-D. Choi, Calphad, 16, 151-59(1992).
assessment that models this phase; reports values for this phase
HCP_A3 (Co–Si)
- Id:
phase:co-si:hcp-a3; statusassigned - Structure: Mg · A3 · hP2 · P6_3/mmc (194); type
st:a3-mg-hp2; tier A: standard phase name; confidence high - Stability: stable in 2 of 2 calculated diagram(s): 300–1963.38 K, x(Si) 0–0.69033
- Literature: 15 values (15 accepted) from 2 papers
- Interactive: phase registry entry
Names (5): corpus: corpus:phase:co-si:hcp-a3
paper: paper:10.1016/0364-5916(92)90003-g:ε-Co, paper:10.1016/j.calphad.2006.06.001:(εCo)
tdb: tdb:CoSi-06Zha.tdb:HCP_A3, tdb:CoSi-92Cho-LB.tdb:HCP_A3
TDB models of HCP_A3 (2): PHASE and CONSTITUENT statements as written
CoSi-06Zha.tdb: HCP_A3, type code %A, sha256 849716b03f938610…
38: PHASE HCP_A3 %A 2 1 0.5 ! 39: CONST HCP_A3 : CO SI : VA : !
CoSi-92Cho-LB.tdb: HCP_A3, type code %A, sha256 9fb5aa520ab17aa5…
44: PHASE HCP_A3 %A 2 1 0.5 ! 45: CONST HCP_A3 : CO SI : VA : !
Example references (2 of 2; assessments first):
- doi:10.1016/j.calphad.2006.06.001 Lijun Zhang, Yong Du, Honghui Xu, Zhu Pan, Experimental investigation and thermodynamic description of the Co–Si system, Calphad 30, 470-481 (2006).
assessment that models this phase; reports values for this phase - doi:10.1016/0364-5916(92)90003-G S.-D. Choi, Calphad, 16, 151-59(1992).
assessment that models this phase; reports values for this phase
LIQUID (Co–Si)
- Id:
phase:co-si:liquid; statusassigned - Structure: liquid; type
st:liquid; liquid; confidence high - Stability: stable in 2 of 2 calculated diagram(s): 1475.55–2500 K, x(Si) 0–1
- Literature: 51 values (51 accepted) from 2 papers
- Interactive: phase registry entry
Names (5): corpus: corpus:phase:co-si:liquid
paper: paper:10.1016/0364-5916(92)90003-g:L, paper:10.1016/j.calphad.2006.06.001:L
tdb: tdb:CoSi-06Zha.tdb:LIQUID, tdb:CoSi-92Cho-LB.tdb:LIQUID
TDB models of LIQUID (2): PHASE and CONSTITUENT statements as written
CoSi-06Zha.tdb: LIQUID, type code %, sha256 849716b03f938610…
23: PHASE LIQUID:L % 1 1 ! 24: CONST LIQUID:L : CO SI : !
CoSi-92Cho-LB.tdb: LIQUID, type code %, sha256 9fb5aa520ab17aa5…
29: PHASE LIQUID:L % 1 1 ! 30: CONST LIQUID:L : CO SI : !
Example references (6 of 6; assessments first):
- doi:10.1016/j.calphad.2006.06.001 Lijun Zhang, Yong Du, Honghui Xu, Zhu Pan, Experimental investigation and thermodynamic description of the Co–Si system, Calphad 30, 470-481 (2006).
assessment that models this phase; reports values for this phase - doi:10.1016/0364-5916(92)90003-G S.-D. Choi, Calphad, 16, 151-59(1992).
assessment that models this phase; reports values for this phase - doi:10.2320/jinstmet1937.1.3_135 Uichi Haschimoto, The Equilibrium Diagram of the Cobalt-Silicon system, J.Japan Inst.Metals 1, 135-143 (1937).
cited as the source of values for this phase - doi:10.1002/srin.193400094 Rudolf Vogel, Kurt Rosenthal, Das Zustandsschaubild Kobalt-Silizium, Archiv für das Eisenhüttenwesen 7, 689-691 (1934).
cited as the source of values for this phase - doi:10.1007/bf02645074 K Ishida, T Nishizawa, M. E Schlesinger, The Co-Si (Cobalt-Silicon) system, JPE 12, 578-586 (1991).
cited as the source of values for this phase - doi:10.1016/0001-6160(72)90001-6 J Van Den Boomgaard, F.M.A Carpay, The eutectoid Co3Si phase in the Co-Si system, Acta Metallurgica 20, 473-476 (1972).
cited as the source of values for this phase