Welcome to phonopy

Phonopy is an open source package for phonon calculations at harmonic and quasi-harmonic levels.

Phonopy-1.9.7 is the stable version and 1.10.0 is an experimental release toward python 3 support.

Phono3py for phonon-phonon interaction calculations has been released as an open beta version. See the document at http://phonopy.sourceforge.net/phono3py/ .

Phonon database: A collection of phonon and mode-Gruneisen parameter calculations is available at http://phonondb.mtl.kyoto-u.ac.jp/ . The raw data of phonopy & VASP results can be downloaed.

Selected features

Selected features of harmonic and quasi-harmonic phonons are:

  • Phonon dispersion relation (band structure)
  • Phonon DOS and partial-DOS
  • Phonon thermal properties, free energy, heat capacity (Cv), and entropy
  • Phonon group velocity
  • Thermal expansion and heat capacity at constant pressure (Cp) within quasi-harmonic approximation (phonopy-qha)
  • Mode Grüneisen parameters (gruneisen)
  • Non-analytical-term correction, LO-TO splitting (Born effective charges and dielectric constant are required.)
  • Creation of atomic modulations of normal modes
  • Characters of irreducible representations of normal modes
  • Crystal symmetry tools
  • Python module (Phonopy can be used in python script.)
  • Graphical plots

i0 i1 i2 i3

Interfaces to calculators

For the other calculators, input files under certain formats (force sets or force constants) are required. But the interfaces for popular calculators may be implemented if requested.

Mailing list

For questions, bug reports, and comments, please visit following mailing list:


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New BSD from version 1.3.

(LGPL from ver. 0.9.3 to version 1.2.1., GPL to version 0.9.2.)