Example: User-defined Brillouin zone for phonon dispersion¶

#!/bin/sh

# This example shows how to specify a user-defined path through the 
# Brillouin zone (BZ) when computing the phonon dispersion curves.

# Note: when computing the phonons, you should first run a geometry 
# optimization (including relaxation of lattice vectors). 
# Here we use a pre-optimized structure.

AMS_JOBNAME=BoronNitrade $AMSBIN/ams << eor

Task SinglePoint

System
    Atoms
        B 0.0              0.0              0.0 
        N 0.92538708336681 0.92538708336681 0.92538708336681 
    End
    Lattice
        0.0             1.8507741667336 1.8507741667336
        1.8507741667336 0.0             1.8507741667336
        1.8507741667336 1.8507741667336 0.0
    End
End

Properties 
    Phonons Yes
End

NumericalPhonons
    SuperCell
        2 0 0
        0 2 0
        0 0 2
    End

    # Disable the automatically generated path though the BZ

    AutomaticBZPath No

    BZPath
        # In each 'Path' block you should define the vertices of the path
        # in fractional coordinates (with respect to the reciprocal lattice 
        # vectors)

        # First segment: Gamma-X-W-K
        Path
             0.0   0.0   0.0  G
             0.5   0.0   0.5  X
             0.5   0.25  0.75 W
             0.375 0.375 0.75 K
        End

        # Second segment: Gamma-SomeRandomPoint
        Path
            0.0  0.0  0.0 G
            0.1  0.2  0.3 RandomPoint
        End
    End
End

Engine DFTB
    Model SCC-DFTB
    ResourcesDir DFTB.org/matsci-0-3
    KSpace Quality=Basic
EndEngine

eor

echo 'Content of phonon_curves section'
$AMSBIN/dmpkf BoronNitrade.results/dftb.rkf 'phonon_curves'
echo 'End content of phonon_curves section'