A presentation in pdf for introduction to phonopy is downloaded ***here***.
Phonon band structure is calculated for the specified band paths. See Band structure tags.
Phonon group velocity is calculated from first derivative of dynamical matrix. See Group velocity.
Helmholtz free energy, heat capacity at constant volume, and entropy at temperatures are calculated from the phonon frequencies on the q-point sampling mesh. See Thermal properties related tags.
Gibbs free energy, heat capacity at constant pressure, and thermal expansion are calcualted with quasi-harmonic approximation. See Quasi harmonic approximation.
How far atoms are displaced from their equilibrium positions at temperatures is calculated as mean square displacements. See Thermal displacements.
gruneisen is used for calculating mode Grüneisen
parameters in band structure style and mesh sampling style. See the
details at Calculation of mode Grüneisen parameters.
Irreducible representations are assigned using polarization vectors of phonon normal modes (Characters of irreducible representations). Atomic displacements corresponding to the real part of the polarization vectors are obtained (Create modulated structure). This may be applied for research of the second-order like structural phase transition.
The results of DOS, PDOS, band structure, and thermal properties are
immediately plotted by specifying
(Graph plotting). When
-s option is set together with the
-p option, the plot is stored in the PDF file
(-p -s). In addition those results are saved
in output text files (Output files), too.
Work flow of phonopy is shown schematically. There are two ways to calculate, (1) atomic forces from finite displacements and (2) given force constants. You can choose one of them. Forces on atoms or force constants are calculated by your favorite calculator (shown by the diamonds in the work flow). The boxes are jobs being done by phonopy, and the circles are input and intermediate output data structures.