First-principles study on the lattice dynamics of FeSb2

The lattice dynamics of FeSb2 are investigated by first-principles calculations based on a plane wave pseudopotential method. Phonon spectrum and the electron–phonon linewidths at the Γ -point are obtained using the density-functional perturbation theory within the linear response method. Nine phonon modes are in good agreement with the experimental data, but the B 3 g mode shows unusually large disagreement. In order to investigate the possibility of anharmonicity of phonon modes, frozen phonon calculations have been performed for the B 1 g 1 , B 1 g 2 and B 3 g modes. But the results are all equal to the density-functional perturbation theory calculations, indicating that the phonons are all harmonic. Our calculated electron–phonon linewidth of the B 1 g 1 mode is consistent with experimental data, and we also confirm the existence of electron–phonon interactions for the A g 1 , B 1 g 1 , and B 1 u modes in FeSb2.