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This page gives hints on how to compute phonon frequencies and modes, IR and Raman spectra, Born effective charges, IR reflectivity … with the ABINIT package.


The computation of the second-order derivative of the total energy with respect to atomic displacements at an arbitrary wavevector, using topic_DFPT, opens the possibility to compute the dynamical matrix at that wavevector, and hence, to compute the phonon eigenfrequency and eigendisplacements. When the wavevector is (0,0,0), usually denoted as the Gamma point, the combination of the atomic displacements and electric field type perturbations opens also the access to Born effective charges, electronic (for frequencies lower than the electronic band gap) dielectric constants, and then, to infra-red reflectivity of materials (in the infinite lifetime approximation). See [Gonze1997a] for the presentation of the theory with DFPT.

In ABINIT, with one dataset for a fixed wavevector (see topic_q-points), one can compute all such second-order derivatives. ABINIT will already perform some post-processing treatment of the second-order derivatives (e.g. computation of the dynamical matrix, and corresponding eigenenergies and eigendisplacements), although the most extended post-processing treatment is provided by ANADDB. Thus, there is some overlap of the two executables, with some common input variables. Usually, the action of an input variable with the same name in the two executables is very similar, although there are some input variables that govern more options in ANADDB then in ABINIT, because of the previously mentioned difference in capabilities. In the database of input variables, the input variables related to ABINIT or ANADDB are clearly distinguished.

The band-by-band decomposition of the Born effective charge tensors can be computed thanks to prtbbb. The related localization tensor (see [Veithen2002] can also be computed.

Phonon calculations are arbitrary q-points can be done under finite electric field (topic_Berry).

It will be the easiest to discover the capabilities of these two executables through the rf1 lesson of the tutorial.

See topic_DFPT for the general information about DFPT, topic_q-points for the specification of q-points, and topic_PhononBands for the computation of full phonon bands.


  • rfatpol Response Function: ATomic POLarisation
  • rfdir Response Function: DIRections


  • asr Acoustic Sum Rule
  • dieflag DIElectric FLAG
  • ngqpt Number of Grids points for Q PoinTs
  • rfasr Response Function: Acoustic Sum Rule


  • amu Atomic Mass Units
  • chneut Integer for CHarge NEUTrality treatment
  • chneut CHarge NEUTrality treatment
  • dipdip DIPole-DIPole interaction
  • eivec EIgenVECtors
  • enunit ENergy UNITs
  • frmax FRequency MAXimum
  • frmin FRequency MINimum
  • nfreq Number of FREQuencies
  • prtvol PRinT VOLume
  • q1shft Q shifts for the grid number 1
  • symdynmat SYMmetrize the DYNamical MATrix
  • symdynmat SYMmetrize the DYNamical MATrix


Selected Input Files



  • The lesson Response-Function 1 (RF1) presents the basics of DFPT calculations within ABINIT. The example given is the study of dynamical and dielectric properties of AlAs (an insulator): phonons at Gamma, dielectric constant, Born effective charges, LO-TO splitting, phonons in the whole Brillouin zone. The creation of the “Derivative Data Base” (DDB) is presented.