Logo of Phonon LiNbO_3


K.Parlinsk, Z.Q.Li and Y.Kawazoe,
Ab initio calculations of phonons in LiNbO_3,
Phys.Rev. B 61, 272 (2000).

Crystal: Lithium niobate LiNbO_3
Software: Ab initio VASP ver. 3.8
Space group: ferroelectric phase: rhombohedral, R3c, (C_3v^6), (Z=2); paraelectric phase: rhombohedral, R-3c, (D_3d^6), (Z=2).
Lattice constants: ferroelectric: a=5.0862, c=13.7238 angst; paraelectric: a=5.0970, c=13.7081 angst.
Supercells: rhombohedral 2x2x2.
Pseudopotentials: ultrasoft of Vanderbilt.
k-points: 1x1x1 (gamma).
LO/TO splitting fitted from experiment.
Soft mode A_2u(TO) found in paraelectric phase at k=0.

Phonon dispersion relations of lithium niobate, LiNbO3 in ferroelectric phase (T=0):

Phonon Dispersion Curves of ferroelectric LiNbO_3


Phonon dispersion relations of lithium niobate, LiNbO3 in paraelectric phase (T=0):

Phonon Dispersion Curves of paraelectric LiNbO_3