# Example: Fragments: PtCl4H2 2-¶

Download Frags_PtCl4H2.run

The (scalar) ZORA relativistic option formalism) is used because of the presence of the heavy Pt atom. The complex is built from fragments H2 and PtCl4 2- .

The calculations of the molecule and larger fragments are performed with GGA’s.

Fragments H2 and PtCl4 2-

The two fragments H2 and PtCl4 2- are first calculated, from which we are going to build the final complex.

$ADFBIN/adf <<eor Title H2 R=1.68a.u. NoPrint sfo,frag,functions Units length bohr End Atoms H 0.0 0.0 0.84 H 0.0 0.0 -0.84 End Basis Type DZP End XC GGA becke perdew End Relativistic Scalar ZORA End Input eor mv TAPE21 t21H2  The result file TAPE21 is renamed and saved to serve as fragment file. $adf <<eor
title   PtCl4 (2-)
noprint sfo,frag,functions
units
length   bohr
end
ATOMS
Pt    0           0          0
Cl    4.361580    0.000000   0
Cl    0.000000    4.361580   0
Cl   -4.361580    0.000000   0
Cl    0.000000   -4.361580   0
end

Basis
Type DZP
Pt DZ/Pt.4d
End
xc
GGA  becke perdew
end
relativistic scalar ZORA
charge  -2
end input
eor

mv TAPE21 t21PtCl4


The key charge is used to specify the net total charge. The default for the net total charge is the sum-of-fragment-charges. The fragments (Pt and Cl atoms) have been computed neutrally, but we want to calculate the PtCl4 complex as a 2- ion.

Main calculation

Finally we compute PtCl4 H2 2- from the fragments PtCl4 2- and H2 .

\$ADFBIN/adf <<eor
title   PtCl4 H2
units
length bohr
end
EPRINT
SFO eig ovl
END
xc
GGA  becke perdew
end
relativistic scalar ZORA
ATOMS
Pt   0             0             0             f=PtCl4
Cl   0.000000     -4.361580      0.00000000    f=PtCl4
Cl   0.000000      4.361580      0.00000000    f=PtCl4
Cl  -4.361580      0.000000      0.00000000    f=PtCl4
Cl   4.361580      0.000000      0.00000000    f=PtCl4
H    0.0           0.0           5.58          f=H2
H    0.0           0.0           7.26          f=H2
end
fragments
PtCl4     PtCl4.t21
H2        H2.t21
end
end input
eor


Note that, although the key charge is not supplied, the molecule is not neutral: the default charge (that is, omitting the keys charge, occupations) is the sum-of-fragments: the fragments here are H2 and PtCl4 2- , yielding a net charge for the molecule of minus two.

Note the f= fragment specification in the Atoms block. No fragment-numbering suffix (/n) is required because there is only one fragment of each fragment type.