These are raw data for the Figures1, 3-5 in the paper and Supplementary Figures 1-9 in the Supplementary Information for this work. Please see our paper for detailed descriptions and discussions. Figure 1_source data.xlsx: Results of lattice vibrations for La2Zr2O7. Figure 3_source data.xlsx: Results of phonon group velocity and relaxation time for La2Zr2O7. Figure 4_source data.xlsx: Lattice thermal conductivity of La2Zr2O7. Figure 5_source data.xlsx: Scattering rates and contributions from the ill-defined-in-time modes. Figure S1_source data.xlsx: Frequency-dependent thermal diffusivity of La2Zr2O7. Figure S2_source data.xlsx: Phonon dispersion of La2Zr2O7. Figure S3_source data.xlsx: Heat capacity of La2Zr2O7. Figure S4_source data.xlsx: Phonon dispersion of Tl3VSe4. Figure S5_source data.xlsx: Results of lattice vibrations for Tl3VSe4. Figure S6_source data.xlsx: Lattice Thermal conductivity of Tl3VSe4. Figure S7_source data.xlsx: Heat capacity of Tl3VSe4. Figure S8_source data.xlsx: Scattering rate of La2Zr2O7. Figure S9_source data.xlsx: Convergence test with respect to the Lorentzian broadening width.