Charge-density wave-mediated soft phonon modes suppress the temperature dependence of lattice thermal conductivity in 2H-NbSe₂

See the supplementary material for detailed information on the phonon dispersions within the harmonic approximation, temperature-dependent phonon dispersions, convergence tests of the lattice thermal conductivity with respect to the q-point grids, the temperature dependence of the heat capacity, a comparison of three- and four-phonon scattering processes for 2H- and 1H-NbSe2, respectively, and the out-of-plane lattice thermal conductivity of 2H-NbSe2.