NiCu surface alloy with GGA xc potential

Sample directory: band/NiCu_XC/

This is an important example featuring many important keywords.

The line:
Skip DOS

reduces the length of the output considerably.

A spin-unrestricted calculation can be done by using the keyword
Unrestricted

The Becke Perdew generalized gradient approximation (GGA) for the exchange-correlation functional is invoked through the XC block:

XC
 GGA Always Becke Perdew
End

The subkey ALWAYS indicates that the Becke-Perdew xc potential should be used during the SCF. If this is not specified, the GGA energy will be calculated post-SCF using the LDA density.

$ADFBIN/band << eor
Title Surface alloy: Cu slab with one surface Cu replaced by Ni (1:1)

Comment
 Technical
   Low quadratic K space integration
   Reasonable real space integration accuracy
 Features
   Lattice   : 2D
   Unit cell : 4 atoms, sqrt(2) x sqrt(2), 2 layers
   Basis     : NO+STO w/ core
   Options   : XC functional in SCF
End

Skip DOS

Convergence
 Degenerate default
End

DIIS
 NCycleDamp 15
 DiMix 0.25
End

SCF 
 Mixing 0.10
End

Accuracy 3.5
Kspace 3

Unrestricted

XC
  GGA Always Becke Perdew
End

Units
 Length Angstrom
End

Define
latt=3.61 ! FCC lattice parameter
halflatt=latt/2
End

Lattice
latt 0    0
0    latt 0
End

Atoms Ni
0         0        0
End

Atoms Cu
:: layer 1
halflatt  halflatt 0
:: layer 2
0         halflatt -halflatt
halflatt  0        -halflatt
End

...
EndInput
eor