Example: Density of States: Cu4CO¶
This sample illustrates the DOS property program to compute density-of-states data, for energy-dependent analysis.
First, the Cu4 CO 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
Basis
Type TZP
Core small
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.
The utility program dos requires a file named TAPE21 in the current directory, unless overridden using a TAPE21 keyword (not used in this example).
$ADFBIN/dos << eor
file dostxt
energyrange npoint=36 e-start=-25 e-end=10
tdos
! Cu 3d partial DOS
gpdos
a1 14:22 32:34
a2 5:10
e1:1 18:32 37:42
e1:2 18:32 37:42
end
! The same but using BAS
gpdos
BAS 17:34 57:74 97:114 137:154
end
! The same as above, but using much less complicated input
gpdos
ATYPE Cu d
end
! Overlap PDOS between Cu 3d and CO 2p
opdos
ATYPE Cu 3d
SUBEND
ATOM 5 2p
ATOM 6 2p
end
end input
eor
Here, the total density of states, as well as various partial densities of states, are computed. You may feed the results found in the dostxt file into a plotting program such as gnuplot. The result is not displayed here. See the ADF manual for more detailed info about the dos program.