Element: phonons

Phonon frequencies and eigen vectors for an arbitrary q-point.

This element allows for specification of the following attributes: ngridq (required), deltaph, do, phonontype, reduceq

Attribute: deltaph

Phonon calculations are performed by constructing a supercell corresponding to a particular ${\bf q}$-vector and making a small periodic displacement of the atoms. The magnitude of this displacement is given by deltaph. This should not be made too large, as anharmonic terms could then become significant, neither should it be too small as this can introduce numerical error.

Attribute: do

Decides if the phonon calculation is skipped or recalculated or continued from file.

Attribute: ngridq

Number of q grid points along the basis vector directions.

Attribute: phonontype

Decides which method (supercell or linear response) is used to perform the phonon calculation.

Attribute: reduceq

The attribute reduceq is set to "true" if the $q$-point set is to be reduced with the crystal symmetries.

Element: phonondos

Phonon density of states.

This element allows for specification of the following attributes: ngrdos, nsmdos, ntemp, nwdos

Attribute: ngrdos

Attribute: nsmdos

Attribute: ntemp

Number of temperatures points for the calculation of the thermodynamical properties from the phonon density of states.

Attribute: nwdos

Element: phonondispplot

Phonon dispersion plot.

Element: reformatdynmat

Reads in the dynamical matrix rows from the corresponding files and outputs them in the DYNMAT*.OUT files, taking into account symmetrization and the accoustic sumrule.

Element: interpolate

Interpolates the phonon frequencies on a given q-point set.

This element allows for specification of the following attributes: ngridq (required), vqloff, writeeigenvectors

Attribute: ngridq

q-point grid for interpolation.

Attribute: vqloff

The q-point offset vector in lattice coordinates.

Attribute: writeeigenvectors

Set to true if the phonon eigenvectors are to be interpolated and output in addition to the phonon frequencies.

Reused Elements

The following elements can occur more than once in the input file. There for they are listed separately.

Data Types

The Input definition uses derived data types. These are described here.