I was following the ABINIT DFPT-1 tutorial and is having some doubts.
Once we turn on the electric field to get the LO-TO splitting at Gamma point, is the dynamical matrix listed above the phonon frequency includes the contributions from lo-to splitting? (I feel no, because when I diagonalise the dynamical matrix, I get the phonon frequencies without LO-TO splitting)
Or some post-processing with anaddb is required to get the updated dynamical matrix with LO-TO splitting?
Is it possible to get the dynamical matrix corresponding to the phonon frequencies with non-analytic corrections along some direction, say [100]?
Thanks for the reply. From the qph2l tag, we can get the eigen displacements of the mode along the direction we specify, will it give the corresponding dynamical matrix components?
Is it possible to get the dynamical matrix once we give the qph2l point? From the ANADDB output, I see only the mode energies and the eigen displacements printed. Is there a better way to get the dynamical matrix printed from ABINIT itself without manually calculating it from the eigen values and eigen vectors (D = V E V^T)?
ddb_filepath = “trf2_3.ddb.abo”
! output file name
output_file = “trf2_4.abo”
outdata_prefix = “trf2_4o”