Phonopy is an open source package of phonon calculations based on the supercell approach.

On anharmonic phonopy

We are preparing to release a major update of phonopy with anharmonic phonon calculations: phonon lifetime, lattice thermal conductivity, etc. Currently the code is under the status of closed-beta. This is for the test and optimization of the user interface with the help of test users. Although we plan to release an open-beta with the manual on the web soon, we are ready to distribute the beta-manual in pdf via direct e-mail if we receive contacts from anybody who can be a test user. Some more information on the closed-beta release and how to contact is found at this post in the phonopy mailing list.

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 for 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.)