SCM: Examples

Cu₄CO: Density of States

Sample directory: adf/e_DOS_Cu4CO/

This sample illustrates the DOS property program to compute density-of-states data, for energy-dependent analysis.

First, the Cu₄CO molecule is calculated (ADF), using single-atom fragments.

$ADFBIN/adf <<eor
title  Cu4CO (3,1) from atoms

units
length bohr
end

define
rCu=2.784
end

atoms
1. Cu     rCu      0.0              0.0
2. Cu    -rCu/2    rCu*sqrt(3)/2    0.0
3. Cu    -rCu/2   -rCu*sqrt(3)/2    0.0
4. Cu     0.0      0.0             -rCu*sqrt(2)
5. C      0.0      0.0              2.65
6. O      0.0      0.0              4.91
end

fragments
Cu      t21.Cu
C       t21.C
O       t21.O
end

XC
  GGA  PostSCF    Becke Perdew
END

endinput
eor

The PostSCF feature in the specification of the XC functional is used: the 'Becke-Perdew' GGA corrections are not included self-consistently but applied to the energy evaluation after the self-consistent LDA solution has been obtained.

mv TAPE21 t21.Cu4COh

The TAPE21 result file is saved for later usage.

cp t21.Cu4COh TAPE21

The utility program dos requires a TAPE21 file, with that name.

$ADFBIN/dos << eor
file dostxt

energyrange npoint=36 e-start=-25 e-end=10

tdos
 
gpdos
  a1   10 11 12 13 14
  e1:1 10 11 12 13 14
  e1:2 10 11 12 13 14
end

pdos
  a1   13 15
  a2    3  4
end

opdos
  bas  32
  SUBEND
  bas  1 2 6 7 32 33 34
end

end input
eor

Computed is the total density of states as well as various kinds of partial densities of states. You may feed the results into a plotting program like gnuplot. The result is not displayed here. See the Utilities document for more detailed info about dos.