# Input File Description

## Program: dynmat.x / PHonon / Quantum ESPRESSO (version: 7.2)

> ### TABLE OF CONTENTS

> > INTRODUCTION

> > &INPUT

> > > fildyn | q | amass | asr | remove_interaction_blocks | axis | lperm | lplasma | filout | fileig | filmol | filxsf | loto_2d | el_ph_nsig | el_ph_sigma

> ### INTRODUCTION

> >     Purpose of dynmat.x:

> >     - reads a dynamical matrix file produced by the phonon code

> >     - adds the non-analytical part (if Z* and epsilon are read from
> >       file), applies the chosen Acoustic Sum Rule (if q=0)

> >     - diagonalise the dynamical matrix

> >     - calculates IR and Raman cross sections (if Z* and Raman
> >       tensors are read from file, respectively)

> >     - writes the results to files, both for inspection and for
> >       plotting

> >     Structure of the input data:
> >     ========================================================================

> >     &INPUT
> >        ...specs of namelist variables...
> >     /

## Namelist: &INPUT

fildyn | CHARACTER
Default: | 'matdyn'

>     input file containing the dynamical matrix

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q(i), i=1,3 | REAL
Default: | q = (0,0,0)

>     calculate LO modes (add non-analytic terms) along the direction q (Cartesian axis)

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amass(i), i=1,ntyp | REAL
Default: | amass is read from file fildyn

>     mass for each atom type

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asr | CHARACTER
Default: | 'no'

>     Indicates the type of Acoustic Sum Rule imposed.

>     Allowed values:

> `'no' :`

>       no Acoustic Sum Rules imposed (default)

> `'simple' :`

>       previous implementation of the asr used
>       (3 translational asr imposed by correction of
>        the diagonal elements of the dynamical matrix)

> `'crystal' :`

>       3 translational asr imposed by optimized
>       correction of the dyn. matrix (projection)

> `'one-dim' :`

>       3 translational asr + 1 rotational asr imposed
>       by optimized correction of the dyn. mat. (the
>       rotation axis is the direction of periodicity; it
>       will work only if this axis considered is one of
>       the Cartesian axis).

> `'zero-dim' :`

>       3 translational asr + 3 rotational asr imposed
>       by optimized correction of the dyn. mat.

>     Note that in certain cases, not all the rotational asr
>     can be applied (e.g. if there are only 2 atoms in a
>     molecule or if all the atoms are aligned, etc.).  In
>     these cases the supplementary asr are canceled during
>     the orthonormalization procedure (see below).

>     Finally, in all cases except 'no' a simple correction
>     on the effective charges is performed (same as in the
>     previous implementation).

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remove_interaction_blocks | LOGICAL
Default: | .false.

>     If .true. lines and rows corresponding to atoms that are not displaced
>     are set to 0. This can be used for ph.x calculations with nat_todo set
>     in ph.x, to remove the interaction between the diplaced and fixed parts of the system.

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axis | INTEGER
Default: | 3

>     indicates the rotation axis for a 1D system (1=Ox, 2=Oy, 3=Oz)

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lperm | LOGICAL
Default: | .false.

>     if .true. then calculate Gamma-point mode contributions to
>     dielectric permittivity tensor

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lplasma | LOGICAL
Default: | .false.

>     if .true. then calculate Gamma-point mode effective plasma
>     frequencies, automatically triggers lperm = .true.

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filout | CHARACTER
Default: | 'dynmat.out'

>     output file containing phonon frequencies and normalized
>     phonon displacements (i.e. eigenvectors divided by the
>     square root of the mass and then normalized; they are
>     not orthogonal)

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fileig | CHARACTER
Default: | ' '

>     output file containing phonon frequencies and eigenvectors
>     of the dynamical matrix (they are orthogonal)

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filmol | CHARACTER
Default: | 'dynmat.mold'

>     as above, in a format suitable for molden

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filxsf | CHARACTER
Default: | 'dynmat.axsf'

>     as above, in axsf format suitable for xcrysden

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loto_2d | LOGICAL
Default: | '.false.'

>     set to .true. to activate two-dimensional treatment of LO-TO splitting.

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el_ph_nsig | INTEGER

>     The number of double-delta smearing values used in an electron-phonon
>     coupling calculation.

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el_ph_sigma | REAL

>     The spacing of double-delta smearing values used in an electron-phonon
>     coupling calculation.

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This file has been created by helpdoc utility on Sat Mar 18 19:08:11 CET 2023.