How can measure the luminous efficiency of the radiation (LER) for white LED (i.e., 445 nm InGaN chips YAG:Ce powder, chromaticity coordinates (x, y)= 0.283, 0.305, CCT=8940, CRI=76.1?
the book chapter Chapter Laboratory Measurement of Optical Properties of LEDs
here on researchgate gives a good overview over ecperimental and theoretical aspects of optical properties of LED. Other helpfull papers might be
Tuomas Poikonen, Tomi Pulli, Anna Vaskuri, Hans Baumgartner,
Petri Kärhä, Erkki Ikonen: Luminous efficacy measurement of
solid-state lamps, Metrologia 49 (2012) S135–S140
(doi:10.1088/0026-1394/49/2/S135)
Zheng, Ruisheng. "Luminous efficiency and color rendering of phosphor-converted white LEDs." Journal of Light & Visual Environment 32.2 (2008): 230-233.
If you had the spectrum, you could calculate radiant flux and luminous flux. But you cannot calculate them from color temperature and color rendering index.