Dear All,

Further to Luigi's message, we too have noticed that the internal
coordinate optimisation in ADF2000 is nowhere near as reliable as in
2.3. We find in particular that torsion terms involving say H atoms
attached to aromatic rings become unstable and oscillate through +-10
degrees so that the energies and gradients are low but the angle
convergence is not met.

Then, on other occasions, we get gradients going through the roof for
no good reason. As Luigi finds, ADF2.3 performs much better as
does ADF2000 optimisations in cartesians. However, the latter is not
so convenient for linear transits.

If this problem with ADF2000 optimisations is a general observation,
perhaps we should encourage Stan to take a look.

Rob Deeth

=============================================
= Dr Robert J Deeth
= Inorganic Computational Chemistry Group
= Department of Chemistry
= University of Warwick
= Coventry CV4 7AL, UK
= ph: +44 (0)24 76 523187
= Fax:+44 (0)24 76 524112
= Web: http:/www.warwick.ac.uk/~mssbq
=
= DALTON DISCUSSION 4: Inorganic Reaction Mechanisms
= 10-13 January, 20002
= Kloster Banz, near Bamberg, Germany
= http://www.rsc.org/lap/confs/dd4.htm
=
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Received on 2001-04-26 13:56:32