TABLE OF CONTENTS
INTRODUCTION
&INPUT
fildyn | flfrc | zasr | loto_2d
Line-of-input: nr1 | nr2 | nr3
fileSpecs
nfile | file
INTRODUCTION
Purpose of q2r.x:
It reads force constant matrices C(q) produced by the ph.x code
for a grid of q-points and calculates the corresponding set
of interatomic force constants (IFC), C(R)
Input data format: [ ] = it depends
Structure of the input data:
========================================================================
&INPUT
...specs of namelist variables...
/
[ nr1 nr2 nr3
nfile
file(1)
file(2)
...
file(nfile) ]
Namelist: &INPUT
|
|---|
| fildyn |
CHARACTER |
| Status: |
REQUIRED
|
Input file name (must be specified).
"fildyn"0 contains information on the q-point grid
"fildyn"1-N contain force constants C_n = C(q_n),
where n = 1,...N, where N is the number of
q-points in the irreducible brillouin zone.
Normally this should be the same as specified on input
to the phonon code.
In the non collinear/spin-orbit case the files
produced by ph.x are in .xml format. In this case
fildyn is the same as in the phonon code + the
.xml extension.
|
| flfrc |
CHARACTER |
| Status: |
REQUIRED
|
Output file containing the IFC in real space (must be specified)
|
| zasr |
CHARACTER |
| Default: |
'no'
|
Indicates the type of Acoustic Sum Rules used for the Born
effective charges.
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 force-constants matrix)
- 'crystal' :
3 translational asr imposed by optimized
correction of the IFC (projection)
- 'one-dim' :
3 translational asr + 1 rotational asr
imposed by optimized correction of the IFC (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 IFC.
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 cancelled
during the orthonormalization procedure (see below).
|
| loto_2d |
LOGICAL |
set to .true. to activate two-dimensional treatment
of LO-TO splitting.
|
|
|
IF file {fildyn}0 does not exist :
If a file "fildyn"0 is not found, the code will ignore variable
fildyn and will try to read from the following cards the missing
information on the q-point grid and file names:
Line of input
|
|---|
Syntax:
nr1 nr2 nr3
|
Description of items:
|
nr1, nr2, nr3 |
INTEGER |
dimensions of the FFT grid formed by the q-point grid
|
|
|
Card: fileSpecs |
|---|
Syntax:
|
Description of items:
| nfile |
INTEGER |
number of files containing C(q_n), n=1,nfile
|
| file |
CHARACTER |
names of the files containing C(q_n), n=1,nfile
Note that the name and order of files is not important as
long as q=0 is the first.
|
|
|
|
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