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 U0.413N0.587
Value
Unit
Printed
Reading
Method (class, basis)
Composition
Scatter
Conversion
Effective
-147.161
kJ/mol-atom
5.000e-5
3.5 (unknown, calibrated)
3.5
-140.272
kJ/mol-atom
5.000e-5
3.9 (model_calculated, calibrated)
3.9
Sources
P.-Y. Chevalier, E. Fischer, B. Cheynet, Thermodynamic modelling of the N–U system, Journal of Nuclear Materials 280, 136-150 (2000). doi:10.1016/s0022-3115(00)00043-x