Input files

DFT structure file

Within InterPhon, the interfacial region is supposed to be defined through the statement of constraints on atom movements (selective dynamics). Phonon evaluation proceeds only for the atoms in the defined interface region.

See below example of Cu(111) surface where the top three layers are selected as the surface region. A part of the DFT structure file is shown in VASP, Quantum ESPRESSO, and FHI-aims format.

VASP:

Unknown
1.00000000000000
    2.5712952614000000    0.0000000000000000    0.0000000000000000
    1.2856476307000000    2.2268070170000001    0.0000000000000000
    0.0000000000000000    0.0000000000000000   27.7901687622000004
Cu
7
Selective dynamics
Cartesian
    0.0000000000000000    0.0000000000000000    6.2983610849999998   F   F   F  # atom index = 0
    2.5712951080000002    1.4845379230000000    8.3978147799999991   F   F   F  # atom index = 1
    1.2856475540000001    0.7422689609999999   10.5098654109999998   F   F   F  # atom index = 2
    0.0000000000000000    0.0000000000000000   12.6153545979999997   F   F   F  # atom index = 3
    2.5712951080000002    1.4845379230000000   14.7267644020000006   T   T   T  # atom index = 4
    1.2856475540000001    0.7422689609999999   16.8249826169999999   T   T   T  # atom index = 5
    0.0000000000000000    0.0000000000000000   18.9121107990000006   T   T   T  # atom index = 6

Quantum ESPRESSO:

CELL_PARAMETERS angstrom
    2.5712952614000000    0.0000000000000000    0.0000000000000000
    1.2856476307000000    2.2268070170000001    0.0000000000000000
    0.0000000000000000    0.0000000000000000   27.7901687622000004

ATOMIC_POSITIONS angstrom
Cu   0.0000000000000000    0.0000000000000000    6.2983610849999998  0 0 0
Cu   2.5712951080000002    1.4845379230000000    8.3978147799999991  0 0 0
Cu   1.2856475540000001    0.7422689609999999   10.5098654109999998  0 0 0
Cu   0.0000000000000000    0.0000000000000000   12.6153545979999997  0 0 0
Cu   2.5712951080000002    1.4845379230000000   14.7267644020000006
Cu   1.2856475540000001    0.7422689609999999   16.8249826169999999
Cu   0.0000000000000000    0.0000000000000000   18.9121107990000006

FHI-aims:

lattice_vector   2.5712952614000000    0.0000000000000000    0.0000000000000000
lattice_vector   1.2856476307000000    2.2268070170000001    0.0000000000000000
lattice_vector   0.0000000000000000    0.0000000000000000   27.7901687622000004
atom   0.0000000000000000    0.0000000000000000    6.2983610849999998 Cu
    constrain_relaxation .true.
atom   2.5712951080000002    1.4845379230000000    8.3978147799999991 Cu
    constrain_relaxation .true.
atom   1.2856475540000001    0.7422689609999999   10.5098654109999998 Cu
    constrain_relaxation .true.
atom   0.0000000000000000    0.0000000000000000   12.6153545979999997 Cu
    constrain_relaxation .true.
atom   2.5712951080000002    1.4845379230000000   14.7267644020000006 Cu
atom   1.2856475540000001    0.7422689609999999   16.8249826169999999 Cu
atom   0.0000000000000000    0.0000000000000000   18.9121107990000006 Cu

DFT force file

If the DFT calculations (electronic relaxation) are successfully converged, output files containing atomic forces are created in all DFT programs (e.g., vasprun.xml and OUTCAR in VASP). The force information is used to fill the dynamical matrix elements.

K-point file

The K-point file, which is supported in VASP KPOINTS format, is used for the mesh sampling of k-points.

KPOINTS_dos (file name is arbitrary):

kpoint
0
MP  # Monkhorst-Pack grids, use the first character ‘G’ for Gamma-centered grids.
9 9 1
0.0 0.0 0.0

KPOINTS_band (file name is arbitrary):

kpoint
41
L  # Line path
0.00 0.00 0.00  # G
0.00 0.50 0.00  # M

0.00 0.50 0.00  # M
0.333333 0.333333 0.00  # K

0.333333 0.333333 0.00  # K
0.00 0.00 0.00  # G