MgB12: enthalpy of formation
3 accepted literature formation-enthalpy value(s) (experimental 3); experimental median -10.07 kJ/mol-atom (n = 1); OQMD -0.392 kJ/mol-atom (oqmd-1454219).
Systems: B–Mg
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -15.8 per mol-atom | MgB12 | 298.15 | experimental | Vap. p. | B–Mg | [1] Balducci 2005 | Table 2, p. 4, row 20 report | |
| -10.1 per mol-atom | MgB12 | 298.15 | experimental | calorimetry | B–Mg | [1] Balducci 2005 | Table 2, p. 4, row 21 report | |
| -10.07 kJ/mol-atom ± 0.9 | MgB12 | 298.15 | experimental | calorimetry | B–Mg | [2] Liu 2001 cites Sundman 1985 doi | Table 2, p. 2, row 10 report |
Uncertainty budget
Components kept separate, in the value's unit (literature SCHEMA.md, UNCERTAINTY_CALIBRATION.md): effective = max(sqrt(max(printed, reading, method)^2 + composition^2 + conversion^2), scatter). The method floor is the robust between-study scatter of the method class in ORCHID (calibrated) or a documented prior; printed values and printed uncertainties are unchanged.
| Value | Unit | Printed | Reading | Method (class, basis) | Composition | Scatter | Conversion | Effective |
|---|---|---|---|---|---|---|---|---|
| -15.8 | per mol-atom | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom | unit 'per mol-atom' not convertible to kJ/mol-atom | ||||
| -10.1 | per mol-atom | 0.05 | unit 'per mol-atom' not convertible to kJ/mol-atom | unit 'per mol-atom' not convertible to kJ/mol-atom | ||||
| -10.07 | kJ/mol-atom | 0.9 | 0.005 | 3.2 (solution_reaction_calorimetry, calibrated) | 3.2 |
DFT formation energies
Lowest-energy entries at this composition. Materials Project and OQMD use different energy references and are never averaged. 1 eV/atom = 96.485 kJ/mol-atom.
| Source | Entry | kJ/mol-atom | eV/atom | Space group | E above hull (kJ/mol-atom) | E above hull (eV/atom) | Theoretical |
|---|---|---|---|---|---|---|---|
| OQMD | oqmd-1454219 | -0.392 | -0.004061 | Fm-3m | 7.6551 | 0.0793 | yes |
DFT sources: A. Jain et al., Commentary: The Materials Project: A materials genome approach to accelerating materials innovation, APL Materials 1 (2013) 011002. doi:10.1063/1.4812323 (CC BY 4.0); J. E. Saal et al., JOM 65 (2013) 1501-1509; S. Kirklin et al., npj Comput. Mater. 1 (2015) 15010. doi:10.1007/s11837-013-0755-4 (CC BY 4.0);
Sources
- G. Balducci, S. Brutti, A. Ciccioli, G. Gigli, P. Manfrinetti, A. Palenzona et al., Thermodynamics of the intermediate phases in the Mg–B system, Journal of Physics and Chemistry of Solids 66, 292-297 (2005). doi:10.1016/j.jpcs.2004.06.063
- Zi-Kui Liu, Yu Zhong, D.G. Schlom, X.X. Xi, Qi Li, Computational thermodynamic modeling of the Mg-B system, Calphad 25, 299-303 (2001). doi:10.1016/s0364-5916(01)00050-5