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

Download GO_LiF_Efield.run

#! /bin/sh

# 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.

$ADFBIN/adf <<eor Title LiF Geometry Optimization in Cartesians with new optimizer in the presence of electric field Symmetry NOSYM Atoms F 0.000000 0.800000 0.000000 Li 0.000000 -0.800000 0.000000 End Basis Type TZP Core Small End Geometry Optim Cartesian Converge grad=0.0000004 Iterations 100 End Efield 0.0 0.0 0.01 eor mv TAPE21 LiF.t21 rm logfile$ADFBIN/adf <<eor
Title LiF Geometry Optimization in Cartesians with new optimizer 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
Iterations 100
End

PointCharges
0.0 0.0  5.3  0.5
0.0 0.0 -5.3 -0.5
End

! IT IS IMPORTANT to use the qpnear keyword with a large enough
! value that would include some of the point charges

BeckeGrid
qpnear 20
end

eor

mv TAPE21 LiF_pc.t21
rm logfile