TABLE OF CONTENTS

36a-bands-Si

DESCRIPTION

This example shows how to use the ::pwtk::bands_workflow to:

The structure considered is bulk Si.

EXAMPLE SOURCE FILE

bands-Si.pwtk

SOURCE

# load the pw.x input data with ::pwtk::load_fromPWI

load_fromPWI scf.Si.in

# increase the number of bands & include 4 unoccupied states

SYSTEM { nbnd = 8 }

# calculate and plot the spaghetti BAND structure with the
# ::pwtk::bands_run workflow. The usage is:
#
#    ::pwtk::bands_run ?OPTIONS? NAME UNIT NKTOT KSPECS
#
# Options:
# * -scf          ... requests pw.x SCF calculation
# * -nscf {8 8 8} ... requests pw.x NSCF calculation with denser 8x8x8 non-shifted k-mesh
# * -preserve     ... preserve the 'outdir', i.e., make the BANDS calculations in the outdir copy
# * -dos          ... calculate and plot total DOS alongside spaghetti BAND structure
# * -intdos       ... plot also integrated DOS
# * -gap          ... report the band gap
# * -t png        ... plot into PNG image (spaghetti.Si.png)
# * -v            ... visualize the generated image
#
# For other options, see ::pwtk::plot

DOS { bz_sum = 'tetrahedra_opt'  DeltaE = 0.01 }; # minimal input for dos.x

bands_run -scf -nscf {8 8 8} -preserve -dos -intdos -gap -yr -15:5 -yt -15,5 -my 5 -t png -v  Si crystal 100 {    
    0.000     0.50     0.000     L
    0.000     0.00     0.000     Γ
    0.500     0.50     0.000     X
    0.500     0.75     0.250     W
    0.375     0.75     0.375     K
    0.000     0.50     0.000     L
}


# this is how to calculate the spaghetti bands consisting of several k-path
# segments with discontinuities between them
#
# spaghetti are plotted into the PNG image 'spaghetti.Si-composite.png'
#
# N.B. we omit the SCF calculation because it was already performed above
#
# Option:
# -e pw.Si.nscf.out ... take the Fermi energy from the 'pw.Si.nscf.out' file that was created above

bands_run -e pw.Si.nscf.out -preserve -yr -15:5 -yt -15,5 -my 5 -t png -v  Si-composite crystal 100 {    
    0.000     0.50     0.000     L
    0.000     0.00     0.000     Γ
    0.500     0.50     0.000     X
    0.500     0.75     0.250     W
    0.375     0.75     0.375     K
    0.000     0.50     0.000     L
} {
    0.00     0.000     0.000     Γ
    0.625    0.375     0.000     U
} {
    0.00     0.000     0.000     Γ
    0.00     0.500     0.000     L
}