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 Li4Pb
Value
Unit
Printed
Reading
Method (class, basis)
Composition
Scatter
Conversion
Effective
-34.06
kJ/mol-atom
2.04
0.005
8.395 (dft, calibrated)
8.395
-26.81
kJ/mol-atom
0.005
8.395 (dft, calibrated)
8.395
Sources
Chenyang Zhou, Cuiping Guo, Changrong Li, Zhenmin Du, Thermodynamic optimization of the Li–Pb system aided by first-principles calculations, Journal of Nuclear Materials 477, 95-101 (2016). doi:10.1016/j.jnucmat.2016.04.061