and the diagonal averages of the 𝜿 𝜆 and 𝒗 𝜆 ⊗ 𝒗 𝜆 tensors, i.e. . The 𝜅 𝜆 range from 10 -5 to 1 W m -1 K -1 and are a maximum for the low-frequency acoustic modes as expected. The 𝐶 𝜆 are a shallow function of frequency and vary by ~30 % from 7.4-9.6 × 10 -5 eV over the 9