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.