Element: phonons
Phonon frequencies and eigen vectors for an arbitrary q-point.
contains: | qpointset (optional) phonondos (optional) phonondispplot (optional) reformatdynmat (optional) interpolate (optional) parts (optional) |
XPath: | /input/phonons |
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.
Type: | fortrandouble |
Default: | "0.03d0" |
Use: | optional |
XPath: | /input/phonons/@deltaph |
Attribute: do
Decides if the phonon calculation is skipped or recalculated or continued from file.
Type: | choose from: fromscratch skip |
Default: | "fromscratch" |
Use: | optional |
XPath: | /input/phonons/@do |
Attribute: ngridq
Number of q grid points along the basis vector directions.
Type: | integertriple |
Use: | required |
XPath: | /input/phonons/@ngridq |
Attribute: phonontype
Decides which method (supercell or linear response) is used to perform the phonon calculation.
Type: | choose from: supercell linearresponse |
Default: | "supercell" |
Use: | optional |
XPath: | /input/phonons/@phonontype |
Attribute: reduceq
The attribute reduceq is set to "true" if the $q$-point set is to be reduced with the crystal symmetries.
Type: | boolean |
Default: | "true" |
Use: | optional |
XPath: | /input/phonons/@reduceq |
Element: phonondos
Phonon density of states.
Type: | no content |
XPath: | /input/phonons/phonondos |
This element allows for specification of the following attributes: ngrdos, nsmdos, ntemp, nwdos
Attribute: ngrdos
Type: | no content |
Default: | "100" |
Use: | optional |
XPath: | /input/phonons/phonondos |
Attribute: nsmdos
Type: | no content |
Default: | "" |
Use: | optional |
XPath: | /input/phonons/phonondos |
Attribute: ntemp
Number of temperatures points for the calculation of the thermodynamical properties from the phonon density of states.
Type: | integer |
Default: | "10" |
Use: | optional |
XPath: | /input/phonons/phonondos/@ntemp |
Attribute: nwdos
Type: | no content |
Default: | "500" |
Use: | optional |
XPath: | /input/phonons/phonondos |
Element: phonondispplot
Phonon dispersion plot.
contains: | plot1d |
XPath: | /input/phonons/phonondispplot |
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.
Type: | no content |
XPath: | /input/phonons/reformatdynmat |
Element: interpolate
Interpolates the phonon frequencies on a given q-point set.
Type: | no content |
XPath: | /input/phonons/interpolate |
This element allows for specification of the following attributes: ngridq (required), vqloff, writeeigenvectors
Attribute: ngridq
q-point grid for interpolation.
Type: | integertriple |
Use: | required |
XPath: | /input/phonons/interpolate/@ngridq |
Attribute: vqloff
The q-point offset vector in lattice coordinates.
Type: | vect3d |
Default: | "0.0d0 0.0d0 0.0d0" |
Use: | optional |
XPath: | /input/phonons/interpolate/@vqloff |
Attribute: writeeigenvectors
Set to true if the phonon eigenvectors are to be interpolated and output in addition to the phonon frequencies.
Type: | boolean |
Default: | "false" |
Use: | optional |
XPath: | /input/phonons/interpolate/@writeeigenvectors |
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.