Ga4Na: enthalpy of formation

3 accepted literature formation-enthalpy value(s) (experimental 2, model 1); experimental median -19.2 kJ/mol-atom (n = 2); Materials Project -13.759 kJ/mol-atom (mp-aaaaaarm); OQMD -15.938 kJ/mol-atom (oqmd-17259).

Systems: Ga–Na

Literature values

Enthalpy of formation of Ga4Na reported in the literature (3)
ValuePhase as printedT (K)ClassMethodSystemSourceLocationQuote
-20.9 kJ/mol-atomGa4Na723.15experimentalGa–Na[1] Wang 2007
cites Zabdyr 1983
Table 3, p. 4, row 3
report
-17.5 kJ/mol-atomGa4Na723.15experimentalGa–Na[1] Wang 2007
cites Gambino 1973 doi
Table 3, p. 4, row 2
report
-20.1 kJ/mol-atomGa4Na723.15modelGa–Na[1] Wang 2007Table 3, p. 4, row 1
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.

Uncertainty budget of the literature values of Ga4Na
ValueUnitPrintedReadingMethod (class, basis)CompositionScatterConversionEffective
-20.9kJ/mol-atom0.053.5 (unknown, calibrated)3.5
-17.5kJ/mol-atom0.053.5 (unknown, calibrated)3.5
-20.1kJ/mol-atom0.053.9 (model_calculated, calibrated)3.9

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.

DFT formation energy of Ga4Na
SourceEntrykJ/mol-atomeV/atomSpace groupE above hull (kJ/mol-atom)E above hull (eV/atom)Theoretical
Materials Projectmp-aaaaaarm-13.759-0.142607I4/mmm00no
OQMDoqmd-17259-15.938-0.165181I4/mmm00no

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

  1. Jingfang Wang, Wenxia Yuan, Min Li, Thermodynamic modeling of the Ga–N–Na system, Journal of Crystal Growth 307, 59-65 (2007). doi:10.1016/j.jcrysgro.2007.05.044