CuGd: enthalpy of formation
2 accepted literature formation-enthalpy value(s) (experimental 1, DFT 1); experimental median -10.6 kJ/mol-atom (n = 1); Materials Project -20.386 kJ/mol-atom (mp-aaabiyyx); OQMD -22.451 kJ/mol-atom (oqmd-1976400).
Systems: Cu–Gd
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -10.6 kJ/mol-atom | CuGd | 298.15 | experimental | Cu–Gd | [1] Palumbo 2009 cites Sommer 2009 | Table 2, p. 4, row 21 report | ||
| -26.4 kJ/mol-atom | CuGd | 0 | DFT | ab initio | Cu–Gd | [1] Palumbo 2009 | Table 2, p. 4, row 20 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 |
|---|---|---|---|---|---|---|---|---|
| -10.6 | kJ/mol-atom | 0.05 | 3.5 (unknown, calibrated) | 3.5 | ||||
| -26.4 | kJ/mol-atom | 0.05 | 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-aaabiyyx | -20.386 | -0.211289 | Pm-3m | 0 | 0 | no |
| OQMD | oqmd-1976400 | -22.451 | -0.232693 | P21/m | 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
- M. Palumbo, L. Battezzati, A. Pasturel, S. Gottlieb-Schönmeyer, W. Assmus, Thermodynamic and ab initio investigation of the Cu–Dy system, Calphad 33, 511-516 (2009). doi:10.1016/j.calphad.2009.04.001