Zn2Zr: enthalpy of formation
6 accepted literature formation-enthalpy value(s) (experimental 1, model 3, DFT 2); experimental median -49.3 kJ/mol-atom (n = 1); Materials Project -29.192 kJ/mol-atom (mp-aaaaacbx); OQMD -28.719 kJ/mol-atom (oqmd-18188).
Systems: Zn–Zr
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -49.3 kJ/mol-atom ± 1 | Zn2Zr | 298.15 | experimental | Zn–Zr | [1] Arroyave 2006 cites Chiotti 1960 | Table 5, p. 8, row 24 report | ||
| -31.31 kJ/mol-atom | Zn2Zr | 298.15 | model | Zn–Zr | [1] Arroyave 2006 | Table 5, p. 8, row 29 report | ||
| -31.27 kJ/mol-atom | Zn2Zr | 298.15 | model | Zn–Zr | [1] Arroyave 2006 | Table 5, p. 8, row 27 report | ||
| -30.07 kJ/mol-atom | Zn2Zr | 298.15 | model | Zn–Zr | [1] Arroyave 2006 | Table 5, p. 8, row 28 report | ||
| -31.76 kJ/mol-atom | Zn2Zr | 298.15 | DFT | LDA | Zn–Zr | [1] Arroyave 2006 cites Arroyave 2005 | Table 5, p. 8, row 25 report | |
| -27.91 kJ/mol-atom | Zn2Zr | 298.15 | DFT | GGA | Zn–Zr | [1] Arroyave 2006 cites Arroyave 2005 | Table 5, p. 8, row 26 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 |
|---|---|---|---|---|---|---|---|---|
| -49.3 | kJ/mol-atom | 1 | 0.05 | 3.5 (unknown, calibrated) | 3.5 | |||
| -31.31 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -31.27 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -30.07 | kJ/mol-atom | 0.005 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -31.76 | kJ/mol-atom | 0.005 | 8.395 (dft, calibrated) | 8.395 | ||||
| -27.91 | kJ/mol-atom | 0.005 | 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-aaaaacbx | -29.192 | -0.302553 | Fd-3m | 0 | 0 | no |
| OQMD | oqmd-18188 | -28.719 | -0.297654 | Fd-3m | 0 | 0 | no |
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
- R. Arroyave, Z.K. Liu, Thermodynamic modelling of the Zn–Zr system, Calphad 30, 1-13 (2006). doi:10.1016/j.calphad.2005.12.006