First, dynamical matrices are calculated and saved for a suitable uniform
grid of q-vectors (only those in the Irreducible Brillouin Zone of the
crystal are needed). Although this can be done one q-vector at the time, a
simpler procedure is to specify variable ldisp=.true. and to set
variables nq1, nq2, nq3 to some suitable
Monkhorst-Pack grid, that will be automatically generated, centered at q = 0
Second, code q2r.x reads the dynamical matrices produced in the
preceding step and Fourier-transform them, writing a file of Interatomic Force
Constants in real space, up to a distance that depends on the size of the grid
of q-vectors. Input documentation in the header of PH/q2r.f90.
Program matdyn.x may be used to produce phonon modes and
frequencies at any q using the Interatomic Force Constants file as input.
Input documentation in the header of PH/matdyn.f90.
For more details, see Example 06.
Next: 7.3 Calculation of electron-phonon
Up: 7 Phonon calculations
Previous: 7.1 Single-q calculation
Contents
Paolo Giannozzi
2011-07-17