Since the CRTA method is not usually used for 𝜅 latt calculations, it is interesting to see how the 𝜏 CRTA compare to the actual 𝜏 𝜆 . In these calculations, the 𝜏 CRTA at 300 and 600 K are around twice the average mode lifetime 𝜏̅ 𝜆 (Table , Table .3), which is not surprising given the order of magnitude variation in 𝜏 𝜆 with frequency in Fig. . The 𝜏 CRTA do reflect the average order of magnitude of the 𝜏 𝜆 , and might therefore serve as a useful metric to compare between systems.