BiGd: enthalpy of formation
3 accepted literature formation-enthalpy value(s) (experimental 1, model 1, DFT 1); experimental median -96.7 kJ/mol-atom (n = 1); Materials Project -87.324 kJ/mol-atom (mp-aaabiyzx); OQMD -88.653 kJ/mol-atom (oqmd-1926131).
Systems: Bi–Gd
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -96.7 kJ/mol-atom | GdBi | 298.15 | experimental | Bi–Gd | [1] Wang 2013 cites Borzone 1980 doi | Table 5, p. 3, row 7 report | ||
| -83 kJ/mol-atom | GdBi | 0 | model | Miedema model | Bi–Gd | [1] Wang 2013 cites Colinet 1984 doi | Table 5, p. 3, row 9 report | |
| -90.4625 kJ/mol-atom | GdBi | 0 | DFT | first-principles | Bi–Gd | [1] Wang 2013 | Table 5, p. 3, row 8 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 |
|---|---|---|---|---|---|---|---|---|
| -96.7 | kJ/mol-atom | 5.000e-4 | 3.5 (unknown, calibrated) | 3.5 | ||||
| -83 | kJ/mol-atom | 5.000e-4 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -90.4625 | kJ/mol-atom | 5.000e-6 | 8.395 (dft, calibrated) | 8.395 |
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 |
|---|---|---|---|---|---|---|---|
| Materials Project | mp-aaabiyzx | -87.324 | -0.905058 | Fm-3m | 0 | 0 | no |
| OQMD | oqmd-1926131 | -88.653 | -0.918823 | P-3m1 | 0 | 0 | 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
- Jinsan Wang, Changrong Li, Cuiping Guo, Zhenmin Du, Bo Wu, Thermodynamic assessment of the Gd–Bi and the Ho–Bi systems, Calphad 41, 1-5 (2013). doi:10.1016/j.calphad.2013.01.003