CrGa4: enthalpy of formation
8 accepted literature formation-enthalpy value(s) (experimental 3, model 5); experimental median -7.6 kJ/mol-atom (n = 1); Materials Project -15.083 kJ/mol-atom (mp-aaacixqu); OQMD -14.848 kJ/mol-atom (oqmd-29545).
Systems: Cr–Ga
Literature values
| Value | Phase as printed | T (K) | Class | Method | System | Source | Location | Quote |
|---|---|---|---|---|---|---|---|---|
| -14.5 kJ/mol (basis unstated) ± 1 | CrGa4 | 298.15 | experimental | Precipitation calorimetry | Cr–Ga | [1] Belgacem-Bouzida 2005 | Table 4, p. 4, row 17 report | |
| -7.6 kJ/mol (basis unstated) | CrGa4 | 298.15 | experimental | EMF | Cr–Ga | [1] Belgacem-Bouzida 2005 cites Goncharuk 1981 | Table 4, p. 4, row 14 report | |
| -7.6 kJ/mol-atom | CrGa4 | 850 | experimental | Cr–Ga | [2] Gröbner 1999 cites Gonchuruk 1981 | Table 1, p. 2, row 50 report | ||
| -13.3 kJ/mol (basis unstated) | CrGa4 | model | Assessed | Cr–Ga | [1] Belgacem-Bouzida 2005 | Table 4, p. 4, row 18 report | ||
| -8.7 kJ/mol (basis unstated) | CrGa4 | model | Assessed | Cr–Ga | [1] Belgacem-Bouzida 2005 cites Grobner 1999 doi | Table 4, p. 4, row 15 report | ||
| -8.7 kJ/mol-atom | CrGa4 | 298.15 | model | Cr–Ga | [2] Gröbner 1999 | Table 1, p. 2, row 51 report | ||
| -8 kJ/mol-atom | CrGa4 | 298.15 | model | Cr–Ga | [2] Gröbner 1999 cites F 1988 | Table 1, p. 2, row 52 report | ||
| -8 kJ/mol (basis unstated) | CrGa4 | model | Semi-empirical model | Cr–Ga | [1] Belgacem-Bouzida 2005 cites Djaballah 1999 | Table 4, p. 4, row 16 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 |
|---|---|---|---|---|---|---|---|---|
| -14.5 | kJ/mol (basis unstated) | 1 | 0.05 | 16 (solution_reaction_calorimetry, calibrated) | 16 | |||
| -7.6 | kJ/mol (basis unstated) | 0.05 | 23 (emf, cleaned_below_threshold) | 23 | ||||
| -7.6 | kJ/mol-atom | 0.05 | 3.5 (unknown, calibrated) | 3.5 | ||||
| -13.3 | kJ/mol (basis unstated) | 0.05 | 19.5 (model_calculated, calibrated) | 19.5 | ||||
| -8.7 | kJ/mol (basis unstated) | 0.05 | 19.5 (model_calculated, calibrated) | 19.5 | ||||
| -8.7 | kJ/mol-atom | 0.05 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -8 | kJ/mol-atom | 0.5 | 3.9 (model_calculated, calibrated) | 3.9 | ||||
| -8 | kJ/mol (basis unstated) | 0.5 | 19.5 (model_calculated, calibrated) | 19.5 |
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-aaacixqu | -15.083 | -0.156328 | Im-3m | 0 | 0 | no |
| OQMD | oqmd-29545 | -14.848 | -0.153887 | Im-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
- A. Belgacem-Bouzida, Y. Djaballah, M. Notin, Calorimetric measurement of the intermetallic compounds Cr3Ga and CrGa4 and thermodynamic assessment of the (Cr–Ga) system, Journal of Alloys and Compounds 397, 155-160 (2005). doi:10.1016/j.jallcom.2005.01.026
- J. Gröbner, R. Wenzel, G. G. Fischer, R. Schmid-Fetzer, Thermodynamic calculation of the binary systems M-Ga and investigation of ternary M-Ga-N phase equilibria (M=Ni, Co, Pd, Cr), JPE 20, 615-625 (1999). doi:10.1361/105497199770340608