The phonon code ph.x calculates normal modes at a given q-vector, starting
from data files produced by pw.xwith a simple SCF calculation.
NOTE: the alternative procedure in which a band-structure calculation
with calculation='phonon was performed as an intermediate step is no
longer implemented since version 4.1. It is also no longer needed to
specify lnscf=.true. for q
The output data file appear in the directory specified by variables outdir,
with names specified by variable prefix. After the output file(s) has been
produced (do not remove any of the files, unless you know which are used
and which are not), you can run ph.x.
The first input line of ph.x is a job identifier. At the second line the
namelist &INPUTPH starts. The meaning of the variables in the namelist
(most of them having a default value) is described in file
Doc/INPUT_PH.*. Variables outdir and prefix
must be the same as in the input data of pw.x. Presently
you must also specify amass(i) (a real variable): the atomic mass
of atomic type i
After the namelist you must specify the q-vector of the phonon mode,
in Cartesian coordinates and in units of 2
Notice that the dynamical matrix calculated by ph.x at q = 0
At q = 0
A sample phonon calculation is performed in Example 02.
0
/a
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Paolo Giannozzi
2011-07-17