  The origin of the anomalous anharmonic lattice dynamics of lead telluride is
investigated using molecular dynamics simulations with interatomic force
constants (IFCs) up to quartic terms obtained from first principles. The
calculations reproduce the peak asymmetry of the radial distribution functions
and the double peaks of transverse optical phonon previously observed with
neutron diffraction and scattering experiments. They are identified to be due
to the extremely large nearest-neighbor cubic IFCs in the [100] direction. The
outstanding strength of the nearest-neighbor cubic IFCs relative to the
longer-range ones explains the reason why the distortion in the radial
distribution function is local.
