#!/bin/sh
# The LINEARCONSTRAINTS keyword allows geometry optimizations (old branch) with
# constraints defined by arbitrary linear combinations of (internal)
# coordinates. The constraint has to be satisfied at the start of the geometry
# optimization.
# Example for bond length constraint, where at the start of the linear transit
# rOH1=R1=1.0, and rOH2=R2=1.5, such that (-1.0)*R1+(1.0)*R2=0.5, and in the
# final geometry -R1+R2=0.0 (Reactcoord 0.5 0.0)
$ADFBIN/adf <<eor
title linearconstraints keyword
XC
GGA Becke Perdew
END
Geometry
Branch Old
LinearTransit 6
End
BeckeGrid
Quality good
End
Atoms Internal
O 0 0 0
H 1 0 0 R1
H 1 2 0 R2 109.9
End
GeoVar
R1 =1.
R2 =1.5
End
LinearConstraints
ReactCoord 0.5 0.0
R1 -1.0
R2 1.0
SubEnd
End
Basis
Type DZP
End
eor
mv TAPE21 H2O.t21