Example: CO absorption on a MgO slab: fragment option and PEDA

Download PEDA_MgO+CO.run

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.frag_MgO  0.00000000       0.00000000       0.00000000
   Mg.frag_MgO  1.50260191      -1.50260191      -2.12400000
   Mg.frag_MgO  0.00000000       0.00000000      -4.24800000
   Mg.frag_MgO  3.00520382       0.00000000       0.00000000
   Mg.frag_MgO  1.50260191       1.50260191      -2.12400000
   Mg.frag_MgO  3.00520382       0.00000000      -4.24800000
   O.frag_MgO   1.50260191      -1.50260191       0.00200000
   O.frag_MgO   0.00000000       0.00000000      -2.12400000
   O.frag_MgO   1.50260191      -1.50260191      -4.25000000
   O.frag_MgO   1.50260191       1.50260191       0.00200000
   O.frag_MgO   3.00520382       0.00000000      -2.12400000
   O.frag_MgO   1.50260191       1.50260191      -4.25000000
   O.frag_CO    0.00000000       0.00000000       3.73700000
   C.frag_CO    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.