# Example: Geometry optimization with an external electric field or point charges: LiF¶

Download GO_LiF_Efield.run

In the first example a geometry optimization is performed with an external homogeneous electric field. In the second example a geometry optimization is performed with an external point charges

Note that SYMMETRY NOSYM should be used. In case of point charges it is important to use the QPNEAR subkeyword of the BECKEGRID key with a large enough value that would include some of the point charges.

$ADFBIN/adf << eor Title LiF Cartesian Geometry Optimization in the presence of electric field Symmetry NOSYM Atoms F 0.000000 0.800000 0.000000 Li 0.000000 -0.800000 0.000000 End Basis Type TZP Core Small End Geometry Optim Cartesian Branch New Converge 0.0000001 Iterations 100 End Efield 0.0 0.0 0.01 End Input eor  $ADFBIN/adf << eor
Title LiF Cartesian Geometry Optimization in the presence of point charges
Symmetry NOSYM
Atoms
F             0.000000     0.800000     0.000000
Li            0.000000    -0.800000     0.000000
End
Basis
Type TZP
Core Small
End
Geometry
Optim Cartesian
Branch New
Converge 0.001
Iterations 100
End
Efield &
0.0 0.0  5.3  0.5
0.0 0.0 -5.3 -0.5
End
BeckeGrid
qpnear 20
end
End Input
eor