Example: CO absorption on a MgO slab: fragment option and PEDA¶
This example shall illustrate the use of the Fragment
keywords in combination with the PEDA
keyword to perform the PEDA. For this example two fragment calculations are necessary to calculate the unperturbed eigensystems of the MgO slab and CO fragment.
Fragment calculations¶
# ----------------------------- MgO slab --------------------------
$ADFBIN/band << eor
Title MgO surface
KSpace
Grid 3 3
End
BeckeGrid
quality basic
End
XC
GGA PBE
End
Units
length angstrom
end
Atoms
Mg 0.00000000 0.00000000 0.00000000
Mg 1.50260191 -1.50260191 -2.12400000
Mg 0.00000000 0.00000000 -4.24800000
Mg 3.00520382 0.00000000 0.00000000
Mg 1.50260191 1.50260191 -2.12400000
Mg 3.00520382 0.00000000 -4.24800000
O 1.50260191 -1.50260191 0.00200000
O 0.00000000 0.00000000 -2.12400000
O 1.50260191 -1.50260191 -4.25000000
O 1.50260191 1.50260191 0.00200000
O 3.00520382 0.00000000 -2.12400000
O 1.50260191 1.50260191 -4.25000000
End
Lattice
3.00520382 -3.00520382 0.00000000
3.00520382 3.00520382 0.00000000
End
BasisDefaults
BasisType TZP
Core small
End
END INPUT
eor
mv RUNKF MgO.runkf
# ----------------------------- CO fragment ------------------------
$ADFBIN/band << eor
Title CO molecule
KSpace
Grid 3 3
End
BeckeGrid
quality basic
End
XC
GGA PBE
End
Units
length angstrom
end
Atoms
C 0.00000000 0.00000000 2.61000000
O 0.00000000 0.00000000 3.73700000
End
Lattice
3.00520382 -3.00520382 0.00000000
3.00520382 3.00520382 0.00000000
End
BasisDefaults
BasisType TZP
Core small
End
END INPUT
eor
mv RUNKF CO.runkf
PEDA calculation¶
The two result files, MgO.runkf and CO.runkf, can now be used to perform the PEDA. Here, the mapping of the atoms of the PEDA calculation and the fragment calculations is necessary. And the used grid points in reciprocal space have to be identical in all three calculations.
# ----------------------------- PEDA calculation ------------------------
$ADFBIN/band << eor
Title PEDA
KSpace
Grid 3 3
End
BeckeGrid
quality basic
End
XC
GGA PBE
End
fragment MgO.runkf
1 1
2 2
3 3
4 4
5 5
6 6
7 7
8 8
9 9
10 10
11 11
12 12
end
fragment CO.runkf
2 13
1 14
end
PEDA
units
length angstrom
end
Atoms
Mg 0.00000000 0.00000000 0.00000000
Mg 1.50260191 -1.50260191 -2.12400000
Mg 0.00000000 0.00000000 -4.24800000
Mg 3.00520382 0.00000000 0.00000000
Mg 1.50260191 1.50260191 -2.12400000
Mg 3.00520382 0.00000000 -4.24800000
O 1.50260191 -1.50260191 0.00200000
O 0.00000000 0.00000000 -2.12400000
O 1.50260191 -1.50260191 -4.25000000
O 1.50260191 1.50260191 0.00200000
O 3.00520382 0.00000000 -2.12400000
O 1.50260191 1.50260191 -4.25000000
O 0.00000000 0.00000000 3.73700000
C 0.00000000 0.00000000 2.61000000
End
Lattice
3.00520382 -3.00520382 0.00000000
3.00520382 3.00520382 0.00000000
End
BasisDefaults
BasisType TZP
Core small
End
END INPUT
eor
In the output file the results can be found in the PEDA block after the Energy Analysis.