# Ca–Mg system > Ca–Mg system: 74 accepted literature values (crystal structure 22, formation 19, invariant reaction 19, phase transition 11) and 6 calculated phase diagram(s) from ORCHID, each value with evidence class, source, page and quote. HTML: https://data.orchid-project.org/systems/CA-MG.html · Markdown: https://data.orchid-project.org/systems/CA-MG.md 74 accepted literature values from 5 paper(s) (experimental 25, model 8, DFT 9, unspecified 32); 6 calculated phase diagram(s). 8 further extracted value(s) not accepted by the reader-agreement checks are only in the JSON/CSV. Data: [JSON](https://data.orchid-project.org/literature/systems/CA-MG.json) · [CSV](https://data.orchid-project.org/systems/CA-MG.csv) · [interactive explorer](https://orchid-project.org/data-explorer/#CA-MG) · [interactive phase diagram](https://orchid-project.org/phase-diagrams/#CA-MG/CaMg-05Isl.json) · [phases (9)](https://data.orchid-project.org/phases/pages/CA-MG.html) · [papers (bibliography)](https://data.orchid-project.org/bibliography/pages/systems/CA-MG.html) · [Markdown](https://data.orchid-project.org/systems/CA-MG.md) Table: Accepted values by evidence class | Evidence class | Values | |---|---:| | experimental | 25 | | model | 8 | | DFT | 9 | | unspecified | 32 | Table: Accepted values by property group | Property group | Values | |---|---:| | invariant reaction | 19 | | phase transition | 11 | | formation | 19 | | heat capacity / entropy / enthalpy | 3 | | crystal structure | 22 | ## Calculated phase diagrams Binary phase diagrams calculated with pycalphad 0.11.2 from the SGTE binary collection (Hallstedt 2025, CC BY 4.0). Evidence class: model. Table: Assessments with a calculated phase diagram | TDB file | Assessment | SHA-256 | Links | |---|---|---|---| | CaMg-05Isl.tdb | F. Islam, M. Medraj, Can. Metall. Quart., 44, 523-36(2005). [doi:10.1179/cmq.2005.44.4.523](https://doi.org/10.1179/cmq.2005.44.4.523) | `89c94b67c90207421c18567fc55afcbaa8d6cba7c78db9b994e8adb5baf1e9ae` | [viewer](https://orchid-project.org/phase-diagrams/#CA-MG/CaMg-05Isl.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/CaMg-05Isl.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/CaMg-05Isl.json) | | CaMg-06Zho.tdb | Y. Zhong, K. Ozturk, J.O. Sofo, Z.-K. Liu, J. Alloys Compd., 420, 98-106(2006). [doi:10.1016/j.jallcom.2005.10.033](https://doi.org/10.1016/j.jallcom.2005.10.033) | `4975fabd57c900d50728d319f7ec3ecc6830c32a15c1c981156431dbe1e14f06` | [viewer](https://orchid-project.org/phase-diagrams/#CA-MG/CaMg-06Zho.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/CaMg-06Zho.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/CaMg-06Zho.json) | | CaMg-08Koz.tdb | A. Kozlov, M. Ohno, R. Arroyave, Z.-K. Liu, R. Schmid-Fetzer, Intermetallics, 16, 299-315(2008). [doi:10.1016/j.intermet.2007.10.010](https://doi.org/10.1016/j.intermet.2007.10.010) | `4be2efab4bdbe8082cf28faf1b72380892e4dfad7e97d1cb7de91eb6f2d7bbc2` | [viewer](https://orchid-project.org/phase-diagrams/#CA-MG/CaMg-08Koz.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/CaMg-08Koz.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/CaMg-08Koz.json) | | CaMg-23Hal.tdb | B. Hallstedt, M. Noori, Calphad, 82, 102577(2023). [doi:10.1016/j.calphad.2023.102577](https://doi.org/10.1016/j.calphad.2023.102577) | `76c9ca1f4d8ffe007baa38e76b7dbec96d263ebbb32674f327aa79ef881bdd4d` | [viewer](https://orchid-project.org/phase-diagrams/#CA-MG/CaMg-23Hal.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/CaMg-23Hal.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/CaMg-23Hal.json) | | CaMg-93Hal.tdb | B. Hallstedt, J. Phase Equilib., 14, 662-75(1993). [doi:10.1007/BF02667878](https://doi.org/10.1007/BF02667878) | `c8851e28a70ea868af22f96f765a54cd569470ec0050bf354ec1e6b4f257d38a` | [viewer](https://orchid-project.org/phase-diagrams/#CA-MG/CaMg-93Hal.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/CaMg-93Hal.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/CaMg-93Hal.json) | | CaMg-95Aga-LB.tdb | R. Agarwal, J.J. Lee, H.L. Lukas, F. Sommer, Z. Metallkd., 86, 103-8(1995). [doi:10.1515/ijmr-1995-860206](https://doi.org/10.1515/ijmr-1995-860206) | `67902d2e36bf24aa37045723b4ec7ddf27d7cb706ce62d7d1888c0afc6eeae50` | [viewer](https://orchid-project.org/phase-diagrams/#CA-MG/CaMg-95Aga-LB.json) · [TDB](https://orchid-project.org/data/databases/sgte-binary/CaMg-95Aga-LB.tdb) · [JSON](https://data.orchid-project.org/phase-diagrams/sgte/CaMg-95Aga-LB.json) | Table: Calculated three-phase invariants (model, mole fraction of the second component) | TDB file | T (K) | Phases at the invariant | |---|---:|---| | CaMg-05Isl.tdb | 789.9 | CAMG2_C14 (x(Mg) 0.66667) + LIQUID (x(Mg) 0.89676) + HCP_A3 (x(Mg) 0.99479) | | CaMg-05Isl.tdb | 789.9 | CAMG2_C14 (x(Mg) 0.66667) + LIQUID (x(Mg) 0.8968) + HCP_A3 (x(Mg) 0.9948) | | CaMg-05Isl.tdb | 719.08 | BCC_A2 (x(Mg) 0) + LIQUID (x(Mg) 0.28863) + CAMG2_C14 (x(Mg) 0.66667) | | CaMg-05Isl.tdb | 719.08 | BCC_A2 (x(Mg) 0) + LIQUID (x(Mg) 0.28843) + CAMG2_C14 (x(Mg) 0.66667) | | CaMg-05Isl.tdb | 716.03 | BCC_A2 (x(Mg) 0) + FCC_A1 (x(Mg) 0) + CAMG2_C14 (x(Mg) 0.66667) | | CaMg-06Zho.tdb | 784.42 | CAMG2_C14 (x(Mg) 0.66763) + LIQUID (x(Mg) 0.89091) + HCP_A3 (x(Mg) 0.99548) | | CaMg-06Zho.tdb | 716.03 | BCC_A2 (x(Mg) 0) + FCC_A1 (x(Mg) 0) + LIQUID (x(Mg) 0.28844) | | CaMg-06Zho.tdb | 710.13 | FCC_A1 (x(Mg) 0) + LIQUID (x(Mg) 0.29196) + CAMG2_C14 (x(Mg) 0.66111) | | CaMg-08Koz.tdb | 789.66 | CAMG2_C14 (x(Mg) 0.66667) + LIQUID (x(Mg) 0.89415) + HCP_A3 (x(Mg) 0.99574) | | CaMg-08Koz.tdb | 789.66 | CAMG2_C14 (x(Mg) 0.66667) + LIQUID (x(Mg) 0.89418) + HCP_A3 (x(Mg) 0.99574) | | CaMg-08Koz.tdb | 718.87 | BCC_A2 (x(Mg) 0) + LIQUID (x(Mg) 0.28696) + CAMG2_C14 (x(Mg) 0.66667) | | CaMg-08Koz.tdb | 718.87 | BCC_A2 (x(Mg) 0) + LIQUID (x(Mg) 0.2868) + CAMG2_C14 (x(Mg) 0.66667) | | CaMg-08Koz.tdb | 716.03 | FCC_A1 (x(Mg) 0) + BCC_A2 (x(Mg) 0) + CAMG2_C14 (x(Mg) 0.66667) | | CaMg-23Hal.tdb | 790.29 | C14_LAVES (x(Mg) 0.6703) + LIQUID (x(Mg) 0.89458) + HCP_A3 (x(Mg) 0.99577) | | CaMg-23Hal.tdb | 722.6 | BCC_A2 (x(Mg) 0.00749) + LIQUID (x(Mg) 0.28743) + C14_LAVES (x(Mg) 0.6596) | | CaMg-23Hal.tdb | 714.11 | FCC_A1 (x(Mg) 0.00672) + BCC_A2 (x(Mg) 0.00714) + C14_LAVES (x(Mg) 0.65996) | | CaMg-93Hal.tdb | 789.02 | CAMG2_C14 (x(Mg) 0.66667) + LIQUID (x(Mg) 0.89821) + HCP_A3 (x(Mg) 0.99885) | | CaMg-93Hal.tdb | 789.02 | CAMG2_C14 (x(Mg) 0.66667) + LIQUID (x(Mg) 0.89823) + HCP_A3 (x(Mg) 0.99885) | | CaMg-93Hal.tdb | 715.87 | FCC_A1 (x(Mg) 0) + LIQUID (x(Mg) 0.27365) + CAMG2_C14 (x(Mg) 0.66667) | | CaMg-95Aga-LB.tdb | 789.65 | CAMG2_C14 (x(Mg) 0.66667) + LIQUID (x(Mg) 0.89414) + HCP_A3 (x(Mg) 0.99574) | | CaMg-95Aga-LB.tdb | 789.65 | CAMG2_C14 (x(Mg) 0.66667) + LIQUID (x(Mg) 0.89418) + HCP_A3 (x(Mg) 0.99574) | | CaMg-95Aga-LB.tdb | 718.81 | BCC_A2 (x(Mg) 0) + LIQUID (x(Mg) 0.28699) + CAMG2_C14 (x(Mg) 0.66667) | | CaMg-95Aga-LB.tdb | 718.81 | BCC_A2 (x(Mg) 0) + LIQUID (x(Mg) 0.28683) + CAMG2_C14 (x(Mg) 0.66667) | | CaMg-95Aga-LB.tdb | 716.03 | FCC_A1 (x(Mg) 0) + BCC_A2 (x(Mg) 0) + CAMG2_C14 (x(Mg) 0.66667) | Convex hulls: [Materials Project DFT hull](https://data.orchid-project.org/hulls/dft-mp/CA/CA-MG.json) · [OQMD DFT hull](https://data.orchid-project.org/hulls/dft-oqmd/CA/CA-MG.json) · [CALPHAD hull CaMg-05Isl](https://data.orchid-project.org/hulls/calphad-sgte/CA/CA-MG--CaMg-05Isl.json) · [CALPHAD hull CaMg-06Zho](https://data.orchid-project.org/hulls/calphad-sgte/CA/CA-MG--CaMg-06Zho.json) · [CALPHAD hull CaMg-08Koz](https://data.orchid-project.org/hulls/calphad-sgte/CA/CA-MG--CaMg-08Koz.json) · [CALPHAD hull CaMg-93Hal](https://data.orchid-project.org/hulls/calphad-sgte/CA/CA-MG--CaMg-93Hal.json) · [CALPHAD hull CaMg-95Aga-LB](https://data.orchid-project.org/hulls/calphad-sgte/CA/CA-MG--CaMg-95Aga-LB.json) ## Invariant reactions (literature) Table: Invariant reactions reported in the literature for the Ca–Mg system (19) | T (K) | Reaction / phases | Compositions (mole fraction) | Class | Source | Location | Quote | |---:|---|---|---|---|---|---| | 798 | eutectic: L -> Mg2Ca+ Mg-hcp | L: Mg 0.886; Mg2Ca: Mg 0.666667 | unspecified | [1] ISLAM 2005; _cites ref. 10_ | Table II, p. 5, row 21; `ORC-DB5EXZOFTY` | | | 798 | eutectic: L \<-> Mg2Ca + Mg-hcp | L: Mg 0.886 | experimental | [2] Islam 2005; _cites Paris 1934_ | Table 9, p. 12, row 11; `ORC-OGF3TUDW4L` | | | 790 | eutectic: L \<-> Mg2Ca + Mg-hcp | L: Mg 0.895 | experimental | [2] Islam 2005; _cites Haughton 1937_ | Table 9, p. 12, row 12; `ORC-PFRTDQHQS3` | | | 790 | eutectic: L -> Mg2Ca+ Mg-hcp | L: Mg 0.895; Mg2Ca: Mg 0.666667 | unspecified | [1] ISLAM 2005; _cites ref. 15_ | Table II, p. 5, row 20; `ORC-YAKVQMUT26` | | | 789.8 | eutectic: L \<-> Mg2Ca + Mg-hcp | L: Mg 0.896 | experimental | [2] Islam 2005 | Table 9, p. 12, row 14; `ORC-MICFU7FYF2` | | | 789.8 | eutectic: L -> Mg2Ca+ Mg-hcp | L: Mg 0.8961; Mg2Ca: Mg 0.666667 | model | [1] ISLAM 2005 | Table II, p. 5, row 22; `ORC-RGZSS2BC3K` | | | 789.5 | eutectic: L -> Mg2Ca+ Mg-hcp | L: Mg 0.895; Mg2Ca: Mg 0.666667 | unspecified | [1] ISLAM 2005; _cites ref. 14_ | Table II, p. 5, row 19; `ORC-FEK2H4ESV3` | | | 789 | eutectic: L \<-> Mg2Ca + Mg-hcp | L: Mg 0.894 | experimental | [2] Islam 2005; _cites Vosskuhler 1937_ | Table 9, p. 12, row 13; `ORC-GHU4PPM2PX` | | | 787 | eutectic: L \<-> Mg2Ca + Mg-hcp | L: Mg 0.878 | experimental | [2] Islam 2005; _cites Baar 1911_ [doi](https://doi.org/10.1002/zaac.19110700126) | Table 9, p. 12, row 10; `ORC-VVGEBTSX77` | | | 733 | eutectic: L -> Mg2Ca+ Ca-fcc | L: Mg 0.266; Mg2Ca: Mg 0.666667 | unspecified | [1] ISLAM 2005; _cites ref. 10_ | Table II, p. 5, row 16; `ORC-THRYQ7KBZV` | | | 733 | eutectic: L \<-> Mg2Ca + Ca-fcc | L: Mg 0.266 | experimental | [2] Islam 2005; _cites Paris 1934_ | Table 9, p. 12, row 6; `ORC-U44TWHOMI2` | | | 719 | eutectic: L -> Mg2Ca+ Ca-fcc | L: Mg 0.286; Mg2Ca: Mg 0.666667 | unspecified | [1] ISLAM 2005; _cites ref. 15_ | Table II, p. 5, row 15; `ORC-477JRI7OVF` | | | 719 | eutectic: L \<-> Mg2Ca + Ca-fcc | L: Mg 0.309 | experimental | [2] Islam 2005; _cites Baar 1911_ [doi](https://doi.org/10.1002/zaac.19110700126) | Table 9, p. 12, row 5; `ORC-OZEEL6CKTO` | | | 719 | eutectic: L \<-> Mg2Ca + Ca-fcc | L: Mg 0.288 | experimental | [2] Islam 2005 | Table 9, p. 12, row 9; `ORC-PEKSTZTHPN` | | | 719 | eutectic: L -> Mg2Ca+ Ca-fcc | L: Mg 0.2883; Mg2Ca: Mg 0.666667 | model | [1] ISLAM 2005 | Table II, p. 5, row 18; `ORC-YR2EOZ5E5C` | | | 718 | eutectic: L \<-> Mg2Ca + Ca-fcc | L: Mg 0.27 | experimental | [2] Islam 2005; _cites Klemm 1947_ [doi](https://doi.org/10.1002/zaac.19472550102) | Table 9, p. 12, row 7; `ORC-4FRXLU32H4` | | | 718 | eutectic: L -> Mg2Ca+ Ca-fcc | L: Mg 0.27; Mg2Ca: Mg 0.666667 | unspecified | [1] ISLAM 2005; _cites ref. 13_ | Table II, p. 5, row 17; `ORC-5RWOUHQ3ET` | | | 718 | eutectic: L -> Mg2Ca+ Ca-fcc | L: Mg 0.27; Mg2Ca: Mg 0.666667 | unspecified | [1] ISLAM 2005; _cites ref. 14_ | Table II, p. 5, row 14; `ORC-J662VCYCVD` | | | 718 | eutectic: L \<-> Mg2Ca + Ca-fcc | | experimental | [2] Islam 2005; _cites Vosskuhler 1937_ | Table 9, p. 12, row 8; `ORC-N43HYLHTXD` | | ## Formation enthalpies Literature values in kJ/mol-atom where the per-atom basis is known. DFT columns: the lowest-energy entry at the same composition (Materials Project 2026.04.13, OQMD v1.8; different energy references, never averaged), from [dft_parity.json](https://data.orchid-project.org/literature/dft_parity.json). Table: Enthalpies of formation, Ca–Mg system (19) | Phase | Compound | Value | T (K) | Class | MP DFT (kJ/mol-atom) | OQMD DFT (kJ/mol-atom) | Source | Location | Quote | |---|---|---:|---:|---|---:|---:|---|---|---| | C14 | | -11.72 kJ/mol-atom | 0 | unspecified | | | [3] Zhong 2006 | Table 4, p. 5, row 1; `ORC-YAFNVUVC7X` | | | C15 | | -11.33 kJ/mol-atom | 0 | unspecified | | | [3] Zhong 2006 | Table 4, p. 5, row 2; `ORC-OY76UFOWVA` | | | C36 | | -11.62 kJ/mol-atom | 0 | unspecified | | | [3] Zhong 2006 | Table 4, p. 5, row 3; `ORC-AWNMO6ZWEX` | | | Ca2Mg-C14 | [Ca2Mg](https://data.orchid-project.org/compounds/Ca2Mg.html) | 26.8549 kJ/mol-atom | 0 | unspecified | 5.636 (mp-aaachdih) | 3.889 (oqmd-290195) | [4] Zhong 2006 | Table 2, p. 4, row 16; `ORC-OOZ4JZME4Z.5bf5d2` | | | Mg2Ca | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -13.5 kJ/mol-atom | 298.15 | experimental | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [2] Islam 2005; _cites King 1964_ [doi](https://doi.org/10.1016/0001-6160%2864%2990056-2) | p. 11; `ORC-3LFXR22QOA.709ed5` | “In this study, the calculated enthalpy of formation of Mg2 Ca intermetallic compound at 298 K is -12.70 kJ/g atom, which is in close agreement with King and Kleppa \[51\] and Davison and Smith \[52\] who reported this value as -13.5 kJ/g atom and -13.17 kJ/g atom, respectively.” | | Mg2Ca | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -13.5 kJ/mol-atom | 298.15 | experimental | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [5] Kozlov 2008; _cites King 1964_ [doi](https://doi.org/10.1016/0001-6160%2864%2990056-2) | Table 2, p. 5, row 4; `ORC-UWGNHDPS6J` | | | Mg2Ca | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -13.17 kJ/mol-atom | 298.15 | experimental | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [2] Islam 2005; _cites Davison 1968_ | p. 11; `ORC-3LFXR22QOA.15c12a` | “In this study, the calculated enthalpy of formation of Mg2 Ca intermetallic compound at 298 K is -12.70 kJ/g atom, which is in close agreement with King and Kleppa \[51\] and Davison and Smith \[52\] who reported this value as -13.5 kJ/g atom and -13.17 kJ/g atom, respectively.” | | Mg2Ca | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -13 kJ/mol-atom | 298.15 | experimental | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [5] Kozlov 2008; _cites Davison 1968_ | Table 2, p. 5, row 6; `ORC-JZ4L4Q7U2N` | | | Mg2Ca | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -12.85 kJ/mol-atom | 298.15 | model | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [5] Kozlov 2008; _cites Agarwal 1995_ | Table 2, p. 5, row 2; `ORC-XFTNAJZ22Q` | | | Mg2Ca | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -12.78 kJ/mol-atom | 298.15 | model | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [5] Kozlov 2008 | Table 2, p. 5, row 3; `ORC-S4AJ47FAEA` | | | Mg2Ca | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -12.7 kJ/mol-atom | 298.15 | experimental | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [5] Kozlov 2008; _cites Gartner 1965_ | Table 2, p. 5, row 5; `ORC-7O4OZG2DBF` | | | Mg2Ca | | -12.37 kJ/mol-atom | 298.15 | DFT | | | [5] Kozlov 2008 | Table 2, p. 5, row 1; `ORC-VKZEPFIM3R` | | | Mg2Ca-C14 | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -20.97 kJ/mol-atom | 0 | unspecified | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [4] Zhong 2006; _cites Pyagai 1990_ | Table 2, p. 4, row 8; `ORC-PZ7TZP7URJ.a0a8e2` | | | Mg2Ca-C14 | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -14.59 kJ/mol-atom | 255.5 | experimental | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [4] Zhong 2006; _cites Chiotti 1964_ [doi](https://doi.org/10.1016/0022-5088%2864%2990053-0) | Table 2, p. 4, row 13; `ORC-RZCL7BY52Z.730e2e` | | | Mg2Ca-C14 | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -13.38 kJ/mol-atom | 298.15 | experimental | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [4] Zhong 2006; _cites King 1964_ [doi](https://doi.org/10.1016/0001-6160%2864%2990056-2) | Table 2, p. 4, row 9; `ORC-NICUD3CMK2.13630a` | | | Mg2Ca-C14 | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -13.04 kJ/mol-atom | 298.15 | experimental | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [4] Zhong 2006; _cites Gartner 1965_ | Table 2, p. 4, row 10; `ORC-IKPTGBFS7P.6f9e12` | | | Mg2Ca-C14 | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -13.04 kJ/mol-atom | 0 | unspecified | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [4] Zhong 2006; _cites Davison 1968_ | Table 2, p. 4, row 11; `ORC-RGWLMRTDMG.5e2caf` | | | Mg2Ca-C14 | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -11.7161 kJ/mol-atom | 0 | unspecified | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [4] Zhong 2006 | Table 2, p. 4, row 6; `ORC-QFNUO7XCBY.c38408` | | | Mg2Ca-C14 | [CaMg2](https://data.orchid-project.org/compounds/CaMg2.html) | -11.29 kJ/mol-atom | 359 | experimental | -10.24 (mp-aaaaadpo) | -12.167 (oqmd-21025) | [4] Zhong 2006; _cites Smith 1961_ | Table 2, p. 4, row 12; `ORC-MFXA4ERQYD.227b60` | | ## Other properties ### Phase transition (11) Table: Phase transition, Ca–Mg system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Phase transition | 984 K | 984 | congruent melting: L -> Mg2Ca; _L: Mg 0.66; Mg2Ca: Mg 0.666667_ | unspecified | [1] ISLAM 2005; _cites ref. 15_ | Table II, p. 5, row 9; `ORC-MLYEGC2LIR` | | | Phase transition | 984.58 K | 984.58 | congruent melting: L -> Mg2Ca; _L: Mg 0.66; Mg2Ca: Mg 0.666667_ | model | [1] ISLAM 2005 | Table II, p. 5, row 10; `ORC-64EU7ICZNR` | | | Phase transition | 984.6 K | 984.6 | congruent melting: L \<-> Mg2Ca; _L: Mg 0.667_ | experimental | [2] Islam 2005 | Table 9, p. 12, row 4; `ORC-VKFIZVK6PK` | | | Phase transition | 987 K | 987 | congruent melting: L \<-> Mg2Ca; _L: Mg 0.667_ | experimental | [2] Islam 2005; _cites Baar 1911_ [doi](https://doi.org/10.1002/zaac.19110700126) | Table 9, p. 12, row 1; `ORC-DAYTJTQVIY` | | | Phase transition | 987 K | 987 | congruent melting: L \<-> Mg2Ca | experimental | [2] Islam 2005; _cites Vosskuhler 1937_ | Table 9, p. 12, row 3; `ORC-QDMTBLKGIR` | | | Phase transition | 988 K | 988 | congruent melting: L -> Mg2Ca; _L: Mg 0.66; Mg2Ca: Mg 0.666667_ | unspecified | [1] ISLAM 2005; _cites ref. 14_ | Table II, p. 5, row 8; `ORC-MABUAJNTBF` | | | Phase transition | 998 K | 998 | congruent melting: L -> Mg-hcp | unspecified | [1] ISLAM 2005; _cites ref. 10_ | Table II, p. 5, row 3; `ORC-PIAOXQUWUC` | | | Phase transition | 998 K | 998 | congruent melting: L \<-> Mg2Ca | experimental | [2] Islam 2005; _cites Paris 1934_ | Table 9, p. 12, row 2; `ORC-XSACUSTWGE` | | | Phase transition | 1115 K | 1115 | congruent melting: L -> Ca-bcc; _Ca-bcc: Mg 0_ | model | [1] ISLAM 2005 | Table II, p. 5, row 7; `ORC-BOJ2NBEMLY` | | | Phase transition | 1115 K | 1115 | congruent melting: L -> Ca-bcc; _Ca-bcc: Mg 0_ | unspecified | [1] ISLAM 2005; _cites ref. 15_ | Table II, p. 5, row 6; `ORC-DIGV5DPQ2G` | | | Phase transition | 1115 K | 1115 | congruent melting: L -> Ca-bcc; _Ca-bcc: Mg 0_ | unspecified | [1] ISLAM 2005; _cites ref. 14_ | Table II, p. 5, row 5; `ORC-JMI5ESIJCE` | | ### Heat capacity / entropy / enthalpy (3) Table: Heat capacity / entropy / enthalpy, Ca–Mg system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Entropy; _printed: S298_ | 36.21 J/mol-atom/K | 298.15 | Mg2Ca; _alloy: Mg 0.666667_ | DFT | [5] Kozlov 2008; _cites Arroyave 2006_ | Table 2, p. 5, row 7; `ORC-GQQ6O2FOLK` | | | Entropy; _printed: S298_ | 32.48 J/mol-atom/K | 298.15 | Mg2Ca; _alloy: Mg 0.666667_ | model | [5] Kozlov 2008; _cites Agarwal 1995_ | Table 2, p. 5, row 8; `ORC-NGIRKMPOWN` | | | Entropy; _printed: S298_ | 32.56 J/mol-atom/K | 298.15 | Mg2Ca; _alloy: Mg 0.666667_ | model | [5] Kozlov 2008 | Table 2, p. 5, row 9; `ORC-WASZNJLU2C` | | ### Crystal structure (22) Table: Crystal structure, Ca–Mg system | Property | Value | T (K) | Phases / composition | Class | Source | Location | Quote | |---|---:|---:|---|---|---|---|---| | Lattice a; _printed: a_ | 6.212 Å | 0 | C14 | unspecified | [3] Zhong 2006 | Table 4, p. 5, row 1; `ORC-5TF4CUFTLZ.79b677` | | | Lattice a; _printed: a_ | 8.76 Å | 0 | C15 | unspecified | [3] Zhong 2006 | Table 4, p. 5, row 2; `ORC-JBXUST33F4` | | | Lattice a; _printed: a_ | 6.2 Å | 0 | C36 | unspecified | [3] Zhong 2006 | Table 4, p. 5, row 3; `ORC-CD5RL4JFUD.7952fc` | | | Lattice a; _printed: a_ | 6.887 Å | 0 | Ca2Mg-C14; _alloy: Mg 0.333333_ | unspecified | [4] Zhong 2006 | Table 2, p. 4, row 16; `ORC-W3LIEBHNAW.8601dd` | | | Lattice a; _printed: a_ | 6.271 Å | | Mg2Ca-C14; _alloy: Mg 0.666667_ | experimental | [4] Zhong 2006; _cites Gingl 1993_ [doi](https://doi.org/10.1524/zkri.1993.206.part-2.313) | Table 2, p. 4, row 7; `ORC-UXCVXS5BUG.2807e5` | | | Lattice a; _printed: a (=b)_ | 6.212 Å | 0 | Mg2Ca-C14; _alloy: Mg 0.666667_ | unspecified | [4] Zhong 2006 | Table 2, p. 4, row 6; `ORC-ZPAMVKC7IH.359742` | | | Lattice a | 4.211 Å | 2 | bcc (A2); _alloy: Mg 0_ | DFT | [3] Zhong 2006 | Table 1, p. 4, row 31; `ORC-CLQDMWYFUM` | | | Lattice a | 4.218 Å | 2 | bcc (A2); _alloy: Mg 0_ | DFT | [3] Zhong 2006 | Table 1, p. 4, row 38; `ORC-IYYKLL4WRL` | | | Lattice a | 4.345 Å | 2 | bcc (A2); _alloy: Mg 0_ | DFT | [3] Zhong 2006 | Table 1, p. 4, row 39; `ORC-MW2KUZ3QYH` | | | Lattice a | 5.545 Å | 2 | fcc (A1); _alloy: Mg 0_ | DFT | [3] Zhong 2006 | Table 1, p. 4, row 30; `ORC-E7MK3JDHXY` | | | Lattice a | 5.344 Å | 2 | fcc (A1); _alloy: Mg 0_ | DFT | [3] Zhong 2006 | Table 1, p. 4, row 36; `ORC-LUKFYXILQI` | | | Lattice a | 5.331 Å | 2 | fcc (A1); _alloy: Mg 0_ | DFT | [3] Zhong 2006 | Table 1, p. 4, row 29; `ORC-MZLMLMSSNX` | | | Lattice a | 5.486 Å | 2 | fcc (A1); _alloy: Mg 0_ | DFT | [3] Zhong 2006 | Table 1, p. 4, row 37; `ORC-OHT66OJTI2` | | | Lattice a | 6.23 Å | 711 (\<) | Mg2Ca; _alloy: Mg 0.666667_ | unspecified | [5] Kozlov 2008 | Table 1, p. 4, row 6; `ORC-S5GHLNLNUB.5395f3` | | | Lattice a | 6.251 not_printed ± 0.004 | 711 (\<) | Mg2Ca; _alloy: Mg 0.666667_ | unspecified | [5] Kozlov 2008 | Table 1, p. 4, row 6; `ORC-S5GHLNLNUB.79a72b` | | | Lattice c; _printed: c_ | 10.05 Å | 0 | C14 | unspecified | [3] Zhong 2006 | Table 4, p. 5, row 1; `ORC-5TF4CUFTLZ.52d842` | | | Lattice c; _printed: c_ | 20.184 Å | 0 | C36 | unspecified | [3] Zhong 2006 | Table 4, p. 5, row 3; `ORC-CD5RL4JFUD.641670` | | | Lattice c; _printed: c_ | 10.836 Å | 0 | Ca2Mg-C14; _alloy: Mg 0.333333_ | unspecified | [4] Zhong 2006 | Table 2, p. 4, row 16; `ORC-W3LIEBHNAW.d0dfe0` | | | Lattice c; _printed: c_ | 10.17 Å | | Mg2Ca-C14; _alloy: Mg 0.666667_ | experimental | [4] Zhong 2006; _cites Gingl 1993_ [doi](https://doi.org/10.1524/zkri.1993.206.part-2.313) | Table 2, p. 4, row 7; `ORC-UXCVXS5BUG.168a11` | | | Lattice c; _printed: c_ | 10.05 Å | 0 | Mg2Ca-C14; _alloy: Mg 0.666667_ | unspecified | [4] Zhong 2006 | Table 2, p. 4, row 6; `ORC-ZPAMVKC7IH.6776bc` | | | Lattice c | 10.141 not_printed ± 0.007 | 711 (\<) | Mg2Ca; _alloy: Mg 0.666667_ | unspecified | [5] Kozlov 2008 | Table 1, p. 4, row 6; `ORC-S5GHLNLNUB.356e1d` | | | Lattice c | 10.15 Å | 711 (\<) | Mg2Ca; _alloy: Mg 0.666667_ | unspecified | [5] Kozlov 2008 | Table 1, p. 4, row 6; `ORC-S5GHLNLNUB.6946c1` | | ## Sources Reporting papers the values were read from (a value cited from another work names that work in its row). 1. F. ISLAM, M. MEDRAJ, THERMODYNAMIC MODELLING OF THE Mg-Al-Ca SYSTEM, Canadian Metallurgical Quarterly 44, 523-536 (2005). [doi:10.1179/cmq.2005.44.4.523](https://doi.org/10.1179/cmq.2005.44.4.523) 2. F. Islam, M. Medraj, The phase equilibria in the Mg–Ni–Ca system, Calphad 29, 289-302 (2005). [doi:10.1016/j.calphad.2005.08.006](https://doi.org/10.1016/j.calphad.2005.08.006) 3. Yu Zhong, Koray Ozturk, Jorge O. Sofo, Zi-Kui Liu, Contribution of first-principles energetics to the Ca–Mg thermodynamic modeling, Journal of Alloys and Compounds 420, 98-106 (2006). [doi:10.1016/j.jallcom.2005.10.033](https://doi.org/10.1016/j.jallcom.2005.10.033) 4. Yu Zhong, Jorge O. Sofo, Alan A. Luo, Zi-Kui Liu, Thermodynamics modeling of the Mg–Sr and Ca–Mg–Sr systems, Journal of Alloys and Compounds 421, 172-178 (2006). [doi:10.1016/j.jallcom.2005.09.076](https://doi.org/10.1016/j.jallcom.2005.09.076) 5. A. Kozlov, M. Ohno, R. Arroyave, Z.K. Liu, R. Schmid-Fetzer, Phase equilibria, thermodynamics and solidification microstructures of Mg–Sn–Ca alloys, Part 1: Experimental investigation and thermodynamic modeling of the ternary Mg–Sn–Ca system, Intermetallics 16, 299-315 (2008). [doi:10.1016/j.intermet.2007.10.010](https://doi.org/10.1016/j.intermet.2007.10.010) ## Please cite - R. Arróyave, J. Saal, D. Shin, ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature (version 2026.10; Version 1, machine-extracted), Zenodo (2026). https://doi.org/10.5281/zenodo.23735569 - R. Arróyave, J. Saal, D. Shin, ORCHID-Diagrams: calculated binary phase diagrams (version 2026.10), Zenodo (2026). https://doi.org/10.5281/zenodo.23735859 - R. Arróyave, J. Saal, D. Shin, ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD) (version 2026.10), Zenodo (2026). https://doi.org/10.5281/zenodo.23735891 - 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 the original source of every value you use (paper_citation / paper_doi, and cited_dois for values the paper cites from earlier work); 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). 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_literature_2026, author = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon}, title = {{ORCHID-Values: thermodynamic and phase-equilibrium values read from the literature}}, version = {2026.10}, publisher = {Zenodo}, year = {2026}, doi = {10.5281/zenodo.23735569}, url = {https://doi.org/10.5281/zenodo.23735569}, note = {Version 1, machine-extracted} } @misc{orchid_phase_diagrams_2026, author = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon}, title = {{ORCHID-Diagrams: calculated binary phase diagrams}}, version = {2026.10}, publisher = {Zenodo}, year = {2026}, doi = {10.5281/zenodo.23735859}, url = {https://doi.org/10.5281/zenodo.23735859} } @misc{orchid_hulls_2026, author = {Arr{\'o}yave, Raymundo and Saal, James and Shin, Dongwon}, title = {{ORCHID-Hulls: binary convex hulls (Materials Project, OQMD, assessed CALPHAD)}}, version = {2026.10}, publisher = {Zenodo}, year = {2026}, doi = {10.5281/zenodo.23735891}, url = {https://doi.org/10.5281/zenodo.23735891} } @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 ORCHID ([CITATION.cff](https://data.orchid-project.org/CITATION.cff)) and the original sources. Quotes are short excerpts kept so that each value can be checked; they remain under the publishers' copyright and are not relicensed. Source papers, page images and full text are not redistributed. Field reference: [SCHEMA.md](https://data.orchid-project.org/literature/SCHEMA.md). Machine-readable guide: [llms.txt](https://data.orchid-project.org/llms.txt). Found an error? The report link of a value (Markdown: its id, ORC-..., in the Location column) opens a pre-filled GitHub issue, https://github.com/orchid-calphad/orchid-data/issues/new?template=report-value-error.yml&record_id=\, carrying only the record id, source and value; [how to contribute](https://orchid-project.org/contribute/).