NaCl

Phonon band structure for NaCl (see Examples/Phonon_bands/NaCl).

Lattice parameter a = 5.64 Å and a 6x6x6 repetition of the primitive cell. Main computational settings:

PAO.EnergyShift 0.01 Ry
PAO.BasisSize   DZP
XC.functional   GGA
XC.authors      PBE
MeshCutoff      500. Ry
MD.FCDispl      0.02 Ang

Electrons

Band structure

electronic band structure

Desity of states

Density of states (DOS) sampled on a grid of 64x64x64 k-points:

electronic density of states

Phonons

Band structure

Phonon band structure computed with different force cutoff radii r = 5.0, 7.0, 9.0 Å:

phonon band structure with force cutoff radii of 5.0 angstroms phonon band structure with force cutoff radii of 7.0 angstroms phonon band structure with force cutoff radii of 9.0 angstroms

Desity of states

Density of states (DOS) sampled on a grid of 64x64x64 k-points:

phonon density of states

Reference results

One important difference is the modes at Gamma. With Inelastica the optical modes are found to be degenerate. The missing LO-TO splitting is likely the effect of macroscopic polarization in polar materials. The long-range electrostatic interactions are not corrected in the current code revisions.

reference phonon density of statesband structure

Raunio, G. & Rolandson, S. Lattice Dynamics of NaCl, KCl, RbCl, and RbF, Phys. Rev. B 2, 2098 (1970).