Ni7Tb2: enthalpy of formation
4 accepted literature formation-enthalpy value(s) (model 3, DFT 1); Materials Project -37.383 kJ/mol-atom (mp-aaacprlj); OQMD -23.361 kJ/mol-atom (oqmd-2028135).
Systems: Ni–Tb
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -45.3 kJ/mol-atom | Tb2Ni7 | model | CALPHAD | Ni–Tb | [1] Rahou 2024 cites Rong 2004 doi | Table 4, p. 7, row 26 report | ||
| -38.3 kJ/mol-atom | Tb2Ni7 | model | CALPHAD | Ni–Tb | [1] Rahou 2024 | Table 4, p. 7, row 24 report | ||
| -35.1 kJ/mol-atom | Tb2Ni7 | model | Miedema model | Ni–Tb | [1] Rahou 2024 cites Niessen 1983 doi | Table 4, p. 7, row 25 report | ||
| -37.3 kJ/mol-atom | Tb2Ni7 | 0 | DFT | Ab initio | Ni–Tb | [1] Rahou 2024 | Table 4, p. 7, row 23 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 |
|---|---|---|---|---|---|---|---|---|
| -45.3 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -38.3 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -35.1 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -37.3 | kJ/mol-atom | 0.05 | 3.929 (dft, calibrated) | 3.929 |
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-aaacprlj | -37.383 | -0.387451 | R-3m | 0 | 0 | no |
| OQMD | oqmd-2028135 | -23.361 | -0.242119 | R-3m | 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
- Z. Rahou, D. Moustaine, Y. Ben-Ali, A. Hallaoui, CALPHAD-Based Thermodynamic Reassessment of Tb-Ni Binary System Supported by Ab-Initio Calculations, J. Phase Equilib. Diffus. 45, 75-85 (2024). doi:10.1007/s11669-024-01089-9